巻号一覧
88 巻, 6 号
選択された号の論文の38件中1～38を表示しています
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Yasufumi EMORI, Hideo IBA, Yoshimi OKADA1980 年 88 巻 6 号 p. 1569-1575
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーTreatment of Pseudomonas phaseolicola double-stranded RNA bacteriophage Ø6 with sodium deoxycholate converted the virions to nucleocapsids, which had in vitro RNA polymerase activity. The incorporation of [3H]UMP continued for at least 7 h. The initial incorporation was detected as intermediate RNA. Radioactivity was chased first into three segments of double-stranded RNA, and then into small, medium, and large species of single-stranded RNA successively via the intermediate RNA. Several copies of single-stranded RNA at least were synthesized from a template. The RNA synthesis clearly took place by a semi-conservative mechanism with respect to templates. That is, 5-bromo UTP was incorporated into one strand of double-stranded RNA to make a hybrid RNA of brominated and unbrominated strands. Furthermore, one strand of the 3H-labeled parental double-stranded RNA was shown to be released as single-stranded RNA.抄録全体を表示PDF形式でダウンロード (2226K) -
I. Purification and CharacterizationEisuke NISHIDA, Hikoichi SAKAI1980 年 88 巻 6 号 p. 1577-1586
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーA new protein factor that modulates microtubule assembly in a Ca2+ or Mg2+ concentration-dependent manner was extracted from porcine brain and purified by ammonium sulfate fractionation, acetone fractionation, chromatography on an affinity column fixed with microtubule proteins, and high speed liquid chromatography. The isolated protein was nearly homogeneous on SDS-polyacrylamide gel, appearing as a 94, 000-dalton polypeptide. The protein gave a single symmetric peak with a relatively large Stokes radius on Sepharose 4 B gel filtration. Moreover, it sedimented as a single homogeneous component with a sedimentation constant of nearly 5 S on sucrose density gradient centrifugation. These analyses indicated the homogeneity of the isolated protein and the asymmetry of its conformation. The purified protein factor slightly inhibited microtubule assembly under standard assembly condition. Increase in the concentration of either free Ca2+ or free Mg2+ markedly enhanced its inhibitory effect. Neither Ni2+ nor Mn2+ potentiated the inhibitory effect of the protein. The inhibition was reversible in a fashion dependent on the concentration of Ca2+ or Mg2+ and appeared to be stoichiometric rather than catalytic. The inhibitory activity was totally destroyed by trypsin digestion, but was very heat stable and was not lost on treatment with N-ethylmaleimide. This new protein factor may play an important role in regulation of microtubule assembly and/or function.抄録全体を表示PDF形式でダウンロード (1404K) -
Seiichi TAKASAKI, Katsuko YAMASHITA, Koji SUZUKI, Akira KOBATA1980 年 88 巻 6 号 p. 1587-1594
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe asparagine-linked sugar chains of cold-insoluble globulin isolated from human plasma were released as oligosaccharides from the polypeptide moiety by hydrazinolysis. These oligosaccharides were N-acetylated and could be labeled by reduction with NaB[3H]4. The yield of radioactive oligosaccharides indicated that the glycoprotein has four asparagine-linked sugar chains in one molecule. More than 90% of the radioactive oligosaccharides contain N-acetylneuraminic acid, and could be separated into two acidic oligosaccharides, A-1 and A-2. By sequential exoglycosidase digestion in combination with methylation studies, their structures were elucidated as Galβ1→4GlcNAcβ1→2Manα1→6(NeuAcα2→6Galβ1→4GlcNAcβ1→2Manα1→3) Manβ1→4GlcNAcβ1→4GlcNAc and NeuAcα2→6Galβ1→4GlcNAcβ1→2Manα1→6 (NeuAcα2→6Gaβ1→4GlcNAcβ1→2Manα1→3)-Manβ1→4GlcNAcβ1→4GlcNAc.抄録全体を表示PDF形式でダウンロード (617K) -
Koshi SAITO, Kunihiro YAMAMOTO, Takaji TAKAI, Sho YOSHIDA1980 年 88 巻 6 号 p. 1595-1600
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe effect of triiodothyronine (T3) on hepatic thyroxine (T4) 5'-monodeiodinase and the subcellular localization of the enzyme were examined in regenerating rat liver, because it seemed likely that the effect of T3 might be accentuated during liver regeneration.
Five days after T3 treatment, the specific activity of the monodeiodinase in the microsomal fraction (105, 000×g pellet) of regenerating liver was increased to 207% of the control value. Lineweaver-Burk plots showed that the Vmax for T4 5'-monodeiodination was about 3 times greater in T3-treated rats than in controls, but that there was no difference between the two groups in the apparent Km value for T4. About 55% of the total enzyme activity was found in the endoplasmic reticulum (ER) of the liver of both controls and T3-treated rats. The subcellular distribution of the enzyme was similar to that of NADPH-cytochrome c reductase (NADPH-cyt c reductase), a marker of the ER, but different from that of Na+, K+-ATPase, a marker of plasma membranes (PM).抄録全体を表示PDF形式でダウンロード (455K) -
Substrate Specificity and Inhibition by Amino AcidsShuji KAWATA, Shuji TAKAYAMA, Kazuto NINOMIYA, Satoru MAKISUMI1980 年 88 巻 6 号 p. 1601-1605
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーPorcine liver aminopeptidase B [EC 3. 4. 11. 6] is highly specific for hydrolysis of β-naphthyl-amides of basic L-amino acids; the Km values for L-arginine β-naphthylamide and L-lysine β-naphthylamide were 0.035 and 0.12mM, respectively. The enzyme was inhibited by various α-amino acids. Among basic amino acids, L-homoarginine and L-arginine were the most potent inhibitors, L-lysine and L-norarginine (α-amino-γ-guanidinobutyric acid) being less inhibitory. Hydrophobic amino acids also inhibited the enzyme competitively. This suggests that there is a hydrophobic region that binds the side chain of the substrates or inhibitors in the specificity site of the enzyme. Studies on the inhibitions by L-arginine derivatives showed that blocking of the α-carboxyl or the α-amino group reduced the inhibitory effect of L-arginine. Porcine liver aminopeptidase B was not inhibited by puromycin, whereas bestatin inhibited the enzyme competitively with a K1 value of 1.4×10-8M. This enzyme had no kinin-converting activity.抄録全体を表示PDF形式でダウンロード (381K) -
Yoshichika KITAGAWA, Eiji OKUHARA1980 年 88 巻 6 号 p. 1607-1613
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe rabbit antiserum against poly(I)•poly(C) purified by hydroxyapatite column chromatography contained three distinct antibodies. They were fractionated into three antibody populations by a series of precipitations (with poly(A)•poly(U), poly(I), and poly(I)•poly(C)) and their specificities were examined by quantitative complement fixation, double diffusion tests and radioimmunoassay. The first population was common to the double helical structure of double-stranded RNAs. The second was specific for poly(I) and the third was specific for poly(I)•poly(C). These studies demonstrated that specific antibodies exclusively reactive with poly(I)•poly(C) existed in the rabbit antiserum against poly(I)•poly(C).抄録全体を表示PDF形式でダウンロード (1519K) -
Hisako KOJIMA, Yoichi TAMAI, Mei SATAKE, Tadashi KURIHARA, Shozo FUJIT ...1980 年 88 巻 6 号 p. 1615-1622
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe light and heavy smooth-surfaced membranes (LSM and HSM), which had densities corresponding to 1.08M and 1.28M sucrose, respectively, were isolated from rat brain and some of their biochemical properties were investigated.
Both LSM and HSM showed high Na+, K+-ATPase activity and, in particular, in HSM the activity was four times (21.55 μmol/mg protein/h) higher than that of the brain homogenate. High 2', 3'-cyclic nucleotide 3'-phosphodiesterase activity (293.4 μmol/mg protein/h) was characteristic of LSM. 5'-Nucleotidase and acetylcholinesterase activities were also higher in LSM than in HSM. SDS-polyacrylamide gel electrophoresis showed that LSM and HSM had many protein component and that low molecular weight proteins such as proteolipid protein and basic protein were almost absent, in contrast with myelin and myelin-like membrane. GM1 ganglioside constituted the major class of total ganglioside in both LSM and HSM. These biochemical findings suggested that LSM is a membrane that has not previously been described, or a membrane fraction related to the oligodendroglial plasma membrane.抄録全体を表示PDF形式でダウンロード (2182K) -
Satoshi YOSHIDA, Hiroshi HORI, Yutaka ORII1980 年 88 巻 6 号 p. 1623-1627
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーSpectrophotometric studies revealed the irreversible photodissociation of reduced cytochrome oxidase-nitric oxide (NO) at 5 K. The dissociated NO recombined as the sample temperature was raised, and the half-recombination temperature was 65 K. The photodissociation at 5 K was also confirmed by a change in the EPR spectrum; that is, ferroheme α-NO signals at gx=2.09 and gm=2.006 were replaced by a new signal at gm=2.03, and this change was reversed at the temperature of liquid nitrogen. Comparison of such behavior with that of cytochrome oxidase-carbon monoxide led us to propose that on photodissociation of NO from heme iron, the NO was trapped specifically at a site near the heme iron producing a new paramagnetic species. Its identification will require further studies.抄録全体を表示PDF形式でダウンロード (343K) -
Ken-Ichi FURUKAWA, Mitsuo IKEBE, Akio INOUE, Yuji TONOMURA1980 年 88 巻 6 号 p. 1629-1641
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーIn order to determine whether or not the main intermediate in the ATPase reaction catalyzed by one of the two heads of myosin molecule is identical with that catalyzed by the other head, we measured the amount of nucleotides bound to myosin and the size of P1 burst under various conditions. The following results were obtained: 1. In the presence of either Mg2+ or Mn2+ ions, myosin, HMM, and S-1 were each capable of binding 0.95±0.08 mol of nucleotides per mol of myosin head. The amounts of nucleotides bound to myosin, HMM, and S-1 in the steady state of ATP hydrolysis were estimated by measuring the ATP-dependent luminescence in the presence of both the luciferin-luciferase system and the pyruvate kinase system. 2. In the presence of Mg2+ ions, the size of the initial P1-burst was always larger than 0.5 mol/mol myosin head. For instance, it was 11 mol/mol myosin head at 1 μM Mg2+ ions, and decreased with increase in Mg2+, concentration, reaching 0.55-0.65 mol/mol myosin head at several mM Mg2+ ions. On the other hand, the P1-burst size in the presence of Mn2+ ions increased with increase in Mn2+ concentration, and it was 0.48±0.04 mol/mol myosin head at Mn2+ concentrations higher than 10 μM. These results support our view that the two heads of myosin are different from one another, and that the myosin-phosphate-ADP complex (MADPP) is produced only at one (burst head) of the two heads.
We also measured the rate of nucleotide release from myosin by two methods. 1. In the first method, nucleotides bound to myosin were released from myosin on addition of excess amounts of MgCTP. ADP thus released was immediately converted into ATP in the presence of excess amounts of pyruvate kinase and phosphoenol pyruvate. Thus, both ADP released and ATP released were measured by the luciferin-luciferase system. The rate of nucleotide release thus measured was found to obey first-order kinetics. The rate constant for nucleotide release was 0.90_??_min-1, slightly higher than the rate constant for ATPase reaction in the steady state, 0.5-0.7min-1 2. In the second method, the ATP released from myosin was rapidly converted into HMMADPP by adding excess amounts of HMM, and the amount of P1, associated with the formation of HMMADPP. was measured. The results thus obtained strongly suggested that the rate of ATP release from the myosin-ATP complex was higher than the rate of the initial P1-burst catalyzed by HMM. In other words, the rate of ATP release in high concentrations of nucleoside triphosphate (NTP) (in the first method) was about equal to the rate of ATP hydrolysis in the steady state, whereas the rate of ATP release in low concentrations of NTP (in the second method) was higher than the rate of ATP hydrolysis in the initial P1-burst which must be much higher than that in the steady state
. On the basis of these results, we concluded that release of ATP from the nonburst head was strongly inhibited by high concentrations of NTP.抄録全体を表示PDF形式でダウンロード (888K) -
Akio INOUE, Yuji TONOMURA1980 年 88 巻 6 号 p. 1643-1651
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーActo-HMM or acto-S-1 was dissociated by the addition of AMPPNP in 50mM KCl, 2mM MgCl2, and 10mM Tris-HCl at pH 7.8 and 20°C, and the extent of dissociation of HMM or S-1 from acto-HMM or acto-S-1, α, was measured by a light-scattering method. The dependence of α on the concentrations of F-actin and of AMPPNP was found to be given by the equation α=1/[1+[A] (1+Ks/[S])/Ka], where [A] and [S] are the concentrations of actin monomer and AMPPNP, respectively. This equation suggested the existence of a ternary complex of F-actin, HMM or S-1, and AMPPNP, since α approached 0 when the F-actin concentration was increased even in the presence of high concentrations of AMPPNP. The dissociation constant of a complex of HMM-AMPPNP with F-actin, Ka, and that of a complex of acto-HMM with AMPPNP, Ks, were estimated to be 5.7±1.5 and 850±200 μM, respectively, for four different preparations. When S-1 was used in place of HMM, the Ka. value increased 2-3 times, while the Ks value remained unchanged.
The rate constant for dissociation of acto-HMM induced by AMPPNP was determined under conditions where α was nearly 1. The time course of decrease in the light-scattering intensity, ΔLS, after adding AMPPNP to acto-HMM was found to be given by the relation-ship ΔLS=ΔLSmax (1-e-vft), where ΔLSmax is ΔLS at t=∞, i.e., at α_??_1. The dependence on AMPPNP concentration, [S], of the apparent first-order rate constant, vf, was found to be given by vf=Ka/(1+Ks/[S]). The values of ka and Ks were 2 s-1 and 810 μm, respectively. The rate constant for binding of F-actin with an HMM-AMPPNP complex was determined under conditions where α was nearly 0. The time course of increase in the light-scattering intensity, ΔLS, after adding a sufficiently high concentration of F-actin to HMM-AMPPNP complex was found to be given by the relationship ΔLS=ΔLSmax (1-e-vrt), where ΔLSmax is ΔLS at t=∞, i.e., at α=0. The apparent first-order rate constant, vr, was found to be given by vr=k-a [A], and the k-a value was found to be 0.12 μM-1•s-1 The ratio, ka/k-a, was almost equal to the Ka value obtained by measuring the dependence of α on [A] and [S].
The dependence of α of acto-HMM on the concentrations of F-actin and AMPPNP was also determined in the presence of 2mM MnCl2 by the light-scattering method. The values of Ka and Ks were found to be 5.8 and 60 μm, respectively. The binding of AMPPNP to HMM in the presence of F-actin was directly measured by an ultracentrifugal separation method at concentrations of F-actin much higher than Ka. We found that the extent of AMPPNP binding was independent of the F-actin concentration, and that AMPPNP bound to each head of HMM with a dissociation constant of 60 μM.抄録全体を表示PDF形式でダウンロード (637K) -
Mitsuo IKEBE, Akio INOUE, Yuji TONOMURA1980 年 88 巻 6 号 p. 1653-1662
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe rate constants of a series of elementary steps in the H-meromyosin (HMM) Mn2+-ATPase [EC 3. 6. 1. 3] and acto-HMM Mn2+-ATPase reactions were determined in 0.1M KCl at 5°C. We found that the rate-limiting step in the HMM Mn2+-ATPase reaction was the liberation of ADP from HMM•ADP, of which the rate constant was estimated to be 0.17 s-1. All the results obtained with the acto-HMM Mn2+-ATPase reaction could be quantitatively explained by a modified Lymn-Taylor mechanism (see Fig. 15). The second-order rate constant for the dissociation of acto-HMM induced by ATP was 3.0×105M-1•s-1, and that for the P1, burst in the acto-HMM ATPase reaction was 1.7×105M-1•s-1. The second-order rate constant for the binding of HMMADP with F-actin was 0.25 s-1•mg-1•ml, and the rate-limiting step in the acto-HMM Mn2+-ATPase reaction was the conversion of HMMADPP into HMM•ADP plus P1, when the F-actin concentration was high.抄録全体を表示PDF形式でダウンロード (645K) -
Akio INOUE, Mitsuo IKEBE, Yuji TONOMURA1980 年 88 巻 6 号 p. 1663-1677
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe extent of binding of myosin heads with F-actin was estimated by a light-scattering and an ultracentrifugal separation method, using well-homogenized F-actin. The extent of binding of HMM or S-1 with F-actin during the ATPase reaction was estimated in 2mM K-PEP, 1 mM MgCl2, and 1mM K-P1 at pH 7.4 and compared with the rate of the acto-HMM ATPase or acto-S-1 ATPase [EC 3. 6. 1. 3] reaction in the steady state. The apparent firstorder rate constant for recombination of the HMM-P-ADP complex, HMMADPP, or the S-1-P-ADP complex, S-1ADPP with F-actin was also determined.
At 20°C, the extent of binding (1-α) increased with increase in the F-actin concentration and approached 1.0 at a sufficiently high concentration of F-actin. The steady-state rate constant of the F-actin-dependent ATPase reaction, Δv0, was proportional to the value of (1-α). On the other hand, the apparent first-order rate constant for recombination of HMMADPP or S-1ADPP with F-actin, vrecomb, was found to be 1/5-1/13 of Δv0. Therefore, we concluded that the main route of ATP hydrolysis at low ionic strength at 20°C is the one via direct decomposition of acto-MADPP and that the ATP hydrolysis cycle does not involve the dissociation step of actomyosin. This conclusion was supported by our finding that a high ATPase activity was observed immediately after adding ATP to acto-HMM, while a high ATPase rate in the steady state was observed after a lag phase required for binding of HMMADPP with F-actin, when the acto-HMM ATPase reaction was started by adding F-actin to a solution containing HMM and ATP.
At 12°C, the rate constant of the acto-HMM ATPase reaction, Δv0, was not proportional to the extent of binding of HMM with F-actin, 1-α, and Δv0 was given by the equation Δv0=(1-α)ΔV0+αvrecomb, where ΔV0. is the value at sufficiently high concentrations of F-actin. The rate constant of the acto-HMM Mn2+-ATPase reaction at low ionic strength at 25°C was also accounted for by the above equation.
The results obtained in this study, together with those described in one of the preceding papers (Ikebe, M., Inoue, A., & Tonomura, Y. (1980) J. Biochem. 88, 1653-1662), clearly demonstrate that in the actomyosin ATPase reaction, ATP is hydrolyzed via two routes: one via direct decomposition of acto-MADPP without dissociation of actomyosin and the other via the route proposed by Lymn and Taylor (Lymn, R. W. & Taylor, E. W. (1971) Biochemistry 10, 4617-4624). The rate of the latter route is limited by the steps for recombination of MADPP with F-actin.
The F-actin-concentration dependence of the apparent first-order rate constant for recombination of HMMADPP with F-actin could be accounted for by the Michaelis-Menten equation. Therefore, HMMADPP produced by the reaction of HMM with ATP may exist largely in a refractory state and may recombine with F-actin only after transformation into a nonrefractory state.抄録全体を表示PDF形式でダウンロード (1043K) -
Amino Acid Sequence and Attachment Sites of Oligosaccharide Units of Porcine Erythrocyte GlycophorinKikuko HONMA, Motowo TOMITA, Akira HAMADA1980 年 88 巻 6 号 p. 1679-1691
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe amino acid sequence of the glycophorin from porcine erythrocyte membrane has been determined by Edman degradation. Porcine glycophorin is a polypeptide chain of 133 amino acid residues and contains 12 oligosaccharide units attached to the amino-terminal side of the molecule. Ten oligosaccharides are linked O-glycosidically to threonine/serine residues and the remaining two oligosaccharides are attached N-glycosidically to asparagine residues. The amino acid sequence is consistent with the transmembrane orientation of glycophorin. Porcine and human glycophorins are similar in amphiphilic property, molecular size, and carbohydrate content, but the two glycophorins differ considerably in the amino acid sequence: particularly, the amino-terminal sequences which are highly glycosylated show no homology.抄録全体を表示PDF形式でダウンロード (927K) -
Kikuko TAKEUCHI1980 年 88 巻 6 号 p. 1693-1702
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーMyosin was prepared from arterial smooth muscle, and a hybrid actomyosin was formed from arterial myosin and rabbit skeletal muscle F-actin. We performed transient kinetics on the ATPase reaction [EC 3. 6. 1. 3] of arterial myosin and the hybrid actomyosin at high ionic strength, and compared the kinetic properties of arterial myosin ATPase with those of skeletal muscle myosin ATPase. No significant difference was found between these two myosins in the size of the initial PS burst, the amount of bound nucleotides, and the rates of various elementary steps in the ATPase reaction. On the other hand, two important differences were observed between the hybrid actomyosin and skeletal muscle actomyosin: (i) The amounts of ATP necessary for complete dissociation of the hybrid and skeletal muscle actomyosins were 2 and 1 mol/mol of myosin, respectively. (ii) The rate of dissociation of the hybrid actomyosin induced by ATP was much lower than that of skeletal muscle actomyosin and also was lower than that of fluorescence enhancement.抄録全体を表示PDF形式でダウンロード (704K) -
Ikuo KIMURA, Ken-ichi ARAI, Koui TAKAHASHI, Shizuo WATANABE1980 年 88 巻 6 号 p. 1703-1713
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーIn a previous paper (Kimura, I., Arai, K., & Watanabe, S. (1979) J. Biochem. 86, 1629-1638), we reported that when myosin was subjected to heat treatment, inactivation of actomyosin ATPase occurred in two steps; an early fast inactivation, followed by a slow inactivation. A further study was conducted on the fast inactivation in the early stage of heat treatment of myosin, and the following results were obtained:
1. As the weight ratio of actin to heat-treated myosin increased, the rate of early inactivation of actomyosin ATPase increased.
2. The superprecipitation activity of actomyosin was also decreased in two steps by heat treatment of myosin: an early fast inactivation and a subsequent slow inactivation were distinguishable.
3. The turbidity of myosin suspensions in 0.05M KCI increased during heat treatment of myosin. The increase also proceeded in two distinct steps, and the rate constants for the two steps of increase were comparable to those for inactivation of actomyosin ATPase.
4. In an electron microscopic study, a new change in the morphology of “thick filaments” of myosin was detectable in the early period of heat treatment, when the fast inactivation of actomyosin ATPase was found to occur; myosin filaments were shorter and thinner than the “regular thick filaments” of untreated myosin, and their size was much more heterogeneous. Heterogeneity of myosin aggregates was also detectable in the sedimentation patterns.
5. The actin-binding ability of myosin or HMM remained unaffected during heat treatment of myosin. The binding ability was estimated in three different ways; by measuring the ATP-induced change in the turbidity of actomyosin solution, the actin-inhibition of EDTA-ATPase of myosin, and the actin-activation of Mg-ATPase of HMM.
6. In a sedimentation study, formation of myosin dimers was not detectable in the early period of heat treatment of myosin, and was detectable only in the later period. Likewise, increase in the light scattering intensity of myosin solutions occurred only in the later period of heat treatment of myosin.
7. Heat treatment caused a decrease in the ATP-induced enhancement of the HMM fluorescence. The decrease was fitted by a single exponential (first-order reaction), and not by two exponentials.
8. Heat-induced change was not detectable either in the light scattering intensity of LMM solutions in 0.5M KCl or in the turbidity of LMM suspensions in 0.05M KCI.
Based on these results, it is strongly suggested that the earliest event in heat denaturation of myosin is loss of the ability of myosin to form “regular thick filaments.”抄録全体を表示PDF形式でダウンロード (2737K) -
Secretion of Four Alkaline DNases by Plasmodia of Physarum polycephalumJaap H. WATERBORG, Martin POOT, Charles M. A. KUYPER1980 年 88 巻 6 号 p. 1715-1721
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーIn plasmodia of Physarum polycephalum, DNase activity with a preference for native DNA was found in a pattern of three or four isoenzymes. During growth a constant specific activity of approx. 0.3 unit of DNase activity per mg protein was found in the plasmodia, with a broad maximum during the G2-phase in the naturally synchronous flat cultures. Under conditions of starvation or sclerotization, DNase activity was secreted by the plasmodia in amounts which were up to ten times higher than the internal level of enzyme activity. Purification of the secreted DNase activity to high purity by three simple chromatographic steps showed that four different DNase isoenzymes existed which were identical with the intracellular ones. The relative abundances of the various isoenzyme forms inside and outside the plasmodia seemed to be slightly different. The possible functions of the DNase activities are discussed.抄録全体を表示PDF形式でダウンロード (553K) -
Tetsuya IGARASHI, Yukio MISHIMA, Masami MURAMATSU, Etsuro OGATA1980 年 88 巻 6 号 p. 1723-1731
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーAfter having defined reliable assay conditions for free and template-bound RNA polymerase I activities, we examined in detail the effect of thyroid hormone in vivo on nucleolar RNA polymerase I in rat liver. The enzyme activity decreased markedly in the hypothyroid state produced by either thyroidectomy, hypophysectomy or by administration of propylthiouracil (PTU). One large dose (25 μg/100g body weight) of T, given intraperitoneally caused a rapid recovery of the enzyme activity within 24h either in the presence or absence of the pituitary. The enzyme activity of both free and chromatin-bound enzyme changed in parallel throughout. A similar recovery was noted after daily subcutaneous injections of a physiological dose (1 μg/100g body weight) of T3 for about 3 weeks. Analyses of subfractions of the enzyme indicated that only IB-type enzyme (the enzyme fraction containing the whole set of subunits) changed in response to thyroid hormone action, also irrespective of the presence or absence of the pituitary. The possibility that thyroid hormone is a major physiological regulator of the synthesis of RNA polymerase I in rat liver is discussed.抄録全体を表示PDF形式でダウンロード (671K) -
Kyoko OGASAHARA, Katsuhide YUTANI, Minoru SUZUKI, Yoshinobu SUGINO, Ma ...1980 年 88 巻 6 号 p. 1733-1738
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe states of tyrosine residues in an α-subunit of wild-type tryptophan synthase from Escherichia coli and a mutant protein which has tyrosine in place of glutamic acid at position 49, were examined by absorption spectrum, spectrophotometric titration of phenolic hydroxyl ionization, and deuteration kinetics of phenolic hydrogen monitored by fluorescence measurement.
The difference absorption spectrum of the mutant protein against the wild-type protein at pH 7.0 and 25°C had peaks at 289, 282, and 276.5 nm. These positions corresponded to those in the absorption spectrum of L-tyrosine derivatives in a non-aqueous solvent at 77K and these bands were well-resolved even at 25°C as if the tyrosine residue were fixed at lower temperature. The titration curve of the mutant protein at 3°C differed from that of the wild-type protein only above pH 12.7, where the difference molar extinction coefficient at 295 nm reached a plateau, indicating that ionization of Tyr 49 took place at an abnormally high pH. These results suggest that Tyr 49 is buried in the hydrophobic interior and fixed in a certain orientation.
The deuterium exchanges of phenolic hydrogen at pH 7.0 and 13°C in the wild-type and mutant proteins consisted of a single and two first order processes, respectively, all three having smaller rate constants than that of free tyrosine, indicating that these tyrosine residues are buried. It is concluded that Tyr 49 in the mutant protein is not on the surface of the molecule.抄録全体を表示PDF形式でダウンロード (463K) -
Yoshinori SATOW, Yuichi WATANABE, Yukio MITSUI1980 年 88 巻 6 号 p. 1739-1755
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーSolvent accessibility (Lee, B. & Richards, F. M. (1971) J. Mol. Biol. 55, 379-400) was calculated for each atom of a bacterial protein proteinase inhibitor SSI (Streptomyces subtilisin inhibitor) based on crystallographic coordinates. Mainly based on this information, various chemical and spectroscopic (UV, Raman, NMR) observations made on the microenvironments of cystines, methionines, tryptophan, histidines, and tyrosines of SSI in solution were evaluated. Crystallographic data and the latter two sets of data were mainly at least qualitatively consistent with each other. These data include (1) the conformation of the two disulfide bridges, (2) the flexibility of the three methionyl side chains, (3) the extent of exposure of the indole ring of a tryptophan, (4) the environment of the two histidines, (5) the environment of the tyrosines, and (6) the hydrogen-deuterium exchangeability of peptide NH's. However, the extents of exposure of tyrosines deduced by solvent perturbation UV difference spectroscopy were significantly larger than those based on solvent accessibility calculations. Possible reasons for this discrepancy are discussed.抄録全体を表示PDF形式でダウンロード (1171K) -
Makio KITADA, Koki HORIKOSHI1980 年 88 巻 6 号 p. 1757-1764
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーMembrane vesicles were isolated from alkalophilic Bacillus No. 8-1, and the active transport of amino acids was studied. The transport of amino acids was dependent upon substrate oxidation and the presence of Na+. Concentrative uptake of amino acids was stimulated by the addition of an artificial electron donor system, ascorbate-phenazine methosulfate (PMS), and to a lesser extent by NADH, while succinate, L-lactate, and α-glycerol-phosphate did not stimulate the uptake. N, N, N', N'-Tetramethyl-p-phenylenediamine (TMPD) and cytochrome c were able to replace PMS, and reduced forms of these compounds were also very efficient electron donors. Amino acid transport was dependent on electron transfer, and inhibition of NADH oxidation by cyanide, 2-heptyl-4-hydroxyquinoline-N-oxide (HOQNO), and sodium azide directly prohibited serine transport. The pH optima for serine transport lay between pH 8 and 9 for all energy sources. Sodium ion stimulated serine transport in the presence of NADH, NADH plus cytochome c or succinate plus PMS, but had no stimulatory effect on the corresponding dehydrogenase activities. Sodium ion was also required for accumulation of serine in response to an artificial membrane potential where the respiratory chain was not operative. These results indicated that the stimulatory effect of Na+ on amino acid uptake was on the transport process itself.抄録全体を表示PDF形式でダウンロード (569K) -
Hisamoto EBATO, Toshiaki ABE, Tamio YAMAKAWA, Kazuo NAGASHIMA1980 年 88 巻 6 号 p. 1765-1772
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe twisted tubular cytoplasmic inclusion bodies were isolated from spleens of four patients with adult form Gaucher's disease. The chemical composition of the CIB (cytoplasmic inclusion bodies) was as follows: proteins, 10%, cholesterol, 10%, phospholipids, 10%, glycolipids, 70%. More than 90% of glycolipids from CIB were glucosylceramide. The structural protein profile of these bodies was examined by SDS-polyacrylamide disc gel electrophoresis on a semimicro-scale (s-PAGE). A similar protein composition which included two glycoproteins was found in all the four cases. The tubular structure of the bodies was changed to a small and round form by the treatment with 1 mM EDTA-Na2 which removed some structural proteins from the bodies. This indicated that some proteins might have an important role in maintaining the tubular structure of CIB.抄録全体を表示PDF形式でダウンロード (2013K) -
Hideaki TSUNEMATSU, Satoru MAKISUMI1980 年 88 巻 6 号 p. 1773-1783
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーEthyl N-benzoyl-p-and m-guanidine-DL-phenylglycinates (DL-Bz-p-GPG-OEt and DL-Bz-m-GPG-OEt), and ethyl N-benzoyl-p-guanidine-L- and D-phenylalaninates (L-Bz-p-GPA-OEt and D-Bz-p-GPA-OEt) were synthesized. The ester of the racemic p-guanidinophenylglycine derivative was completely hydrolyzed by trypsin, pronase, α-chymotrypsin, and thrombin, though hydrolysis by the latter two enzymes was much slower. Papain hydrolyzed this ester substrate stereospecifically at a moderate rate and left the ester derivative of the D-enantiomer unaltered. Optical resolution of DL-Bz-p-GPG-OEt with papain gave N-benzoyl-p-guanidino-L-phenylglycine (L-Bz-p-GPG-OH) and the ester of the D-enantiomer of this amino acid derivative. On the other hand, DL-Bz-m-GPG-OEt was completely hydrolyzed by pronase and was stereospecifically hydrolyzed by papain, but was unaffected by trypsin, α-chymotrypsin, and thrombin. The trypsin-catalyzed hydrolysis of Nα-benzoyl-L-arginine p-nitroanilide (L-Bz-Arg-pNA) was inhibited competitively by this ester.
The specificity constant (kcat/Km) for L-Bz-p-GPG-OEt was about 57 times smaller than that for a specific ester substrate, ethyl Nα-benzoyl-L-argininate (L-Bz-Arg-OEt), while the value for the D-enantiomer of the former is about 14 times larger than that for the D-enantiomer of the latter. L-Bz-p-GPA-OEt has a specificity constant comparable to that for L-Bz-Arg-OEt. The value for the former is about 51 times larger than that for L-Bz-p-GPG-OEt. This suggests that the existence of the β-methylene group in L-Bz-p-GPA-OEt is important in relation to the higher susceptibility of the ester to trypsin-catalyzed hydrolysis. In contrast with the L-enantiomer, D-Bz-p-GPA-OEt was found to be a competitive inhibitor for the hydrolysis of L-Bz-Arg-pNA. A significant difference was found between the stereo-specificities of hydrolysis of the ester substrates of the two amino acid derivatives by trypsin.抄録全体を表示PDF形式でダウンロード (832K) -
Yasutaro HAMAGISHI, Toshikazu OKI, Hiroshi TONE, Taiji INUI1980 年 88 巻 6 号 p. 1785-1792
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーA radioimmunoassay for guanosine-5'-diphosphate-3'-diphosphate (ppGpp) and adenosine-5'-triphosphate-3'-diphosphate (pppApp) has been developed. The assay method is based on competition of an unlabeled highly phosphorylated nucleotide with 3H-labeled highly phosphorylated nucleotide for binding sites on a specific antibody. Antibodies to ppGpp and pppApp were obtained by immunizing rabbits with the antigen prepared by conjugating ppGpp with human serum albumin using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, and with the antigen prepared by conjugating 8-(6-aminohexyl)amino-adenosine-5'-triphos-phate-3'-diphosphate with human serum albumin using glutaraldehyde, respectively. Antibody-bound 3H-labeled highly phosphorylated nucleotides were separated from the free 3H-labeled highly phosphorylated nucleotides by selective adsorption on dextran-coated charcoal.
Displacement plots were linear over a concentration range of 5-1, 000 pmol/assay tube in a log-probit percentage plot.
Application of this method to biological systems offers improved accuracy and convenience compared with the previous 32PO4-labeling technique.抄録全体を表示PDF形式でダウンロード (670K) -
Itaru MIYAMOTO, Sumi NAGASE1980 年 88 巻 6 号 p. 1793-1803
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーA proteodermatansulfate was extracted from rat skin with 4M guanidine hydrochloride containing protease inhibitors at 4°C. It was separated from collagen on DEAE-cellulose in 7M urea and was purified by cesium chloride density gradient centrifugation under associative conditions, DEAE-Sephadex column chromatography and then Sephadex G-200 gel filtration. On SDS-disc electrophoresis, the proteoglycan gave a single band staining for protein and a band of the same mobility staining with periodate-Schiff reagent. The proteoglycan contained 46% protein, and this was bound to dermatansulfate via an O-glycosidic linkage. The proteoglycan also contained 20% uronic acid and 16% hexosamine, but no detectable hydroxyproline. The ratio of galactosamine to glucosamine was 68.
The dermatansulfate, the only glycosaminoglycan, had a hybrid structure containing iduronic acid and glucuronic acid as uronic acids. The content of glucuronic acid in uronic acid was much higher than that of pig skin dermatansulfate. The dermatansulfate had a slightly higher mobility on cellulose acetate electrophoresis than those from other sources.
Gel chromatography on Sepharose CL-6B showed that the molecular weight of the dermatansulfate was 23, 000, while that of the proteoglycan was 36, 000.
The elution profile of a mixture of the proteoglycan and hyaluronic acid on Sepharose 6 B column chromatography was similar to that of the proteoglycan alone.抄録全体を表示PDF形式でダウンロード (2451K) -
Seiichi HASHIDA, Takae TOWATARI, Eiki KOMINAMI, Nobuhiko KATUNUMA1980 年 88 巻 6 号 p. 1805-1811
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe mechanism of inhibition of cathepsin B [EC 3. 4. 22. 1] and cathepsin L [EC 3. 4. 22. -] by E-64 was investigated. Kinetic studies indicated that E-64 was an irreversible inhibitor of these enzymes. [3H] E-64 is incorporated into cathepsin B in a one/one molar ratio in parallel with inactivation of the enzyme. Titration of one of the 10 SH groups of native cathepsin B with 2, 2'-dithiodipyridine resulted in complete loss of enzyme activity. Decrease of titratable SH groups and activity of cathepsin B was proportional to the concentration of E-64 added, indicating that E-64 binds to an equimolar amount of active -SH residues of cathepsin B. The effects of E-64 and its derivatives on lysosomal cathepsin B and cathepsin L in rat liver were studied in vitro and in vivo. The D form of E-64 inhibited the cathepsins both in vitro and in vivo, although its inhibitory effects were less than those of E-64-(L). E-64-b (RR), in which the terminal agmatine of E-64 is replaced by leucine, was as active as E-64-(L) in vitro, but was completely inactive in vivo. Among the E-64 derivatives tested, E-64-c (SS), in which the terminal agmatine of E-64 is replaced by isoarylamide, showed strong inhibitory activity in vivo, like E-64-(L).抄録全体を表示PDF形式でダウンロード (435K) -
Hiroshi YOSHIDA, Ikuko FUKUDA, Masahiro HASHIGUCHI1980 年 88 巻 6 号 p. 1813-1818
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーRibonuclease F1, the guanine-specific ribonuclease of Fusarium moniliforme, was purified to homogeneity by a combination of ethanol fractionation, affinity chromatography and DEAE-cellulose column chromatography. The adsorbent for the affinity chromatography was synthesized by the coupling of periodate-oxidized guanosine 5'-monophosphate to aminohexyl agarose followed by sodium borohydride reduction. Ribonuclease F2, the minor component, was also purified to near homogeneity by the same procedure. Ribonucleases F1 and F2 had the same molecular weight (about 11, 000) as determined by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. They also showed the same amino acid composition and differed only in the isoelectric point: 4.10 for F1 and 3.96 for F2.抄録全体を表示PDF形式でダウンロード (883K) -
Toshiko YAMAMOTO, Kazuko TAHARA, Morio SETAKA, Masafumi YANO, Takao KW ...1980 年 88 巻 6 号 p. 1819-1827
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe permeability properties of multilayer planar membranes of uniformly oriented lipids between a pair of cellulose sheets were investigated. The effect of the two cellulose sheets supporting the lipid membrane on the glucose or the Ca permeation was subtracted empirically, and values of 5×10-6 and 8×10-6cm/s were thus obtained for the permeability coefficients of an egg yolk lecithin (egg PC)-cholesterol membrane of about 200 bilayers to Ca2+ and glucose, respectively. These values are discussed as compared with the permeability coefficients of other model membranes.
The membrane permeability was moderately affected by the addition of chemical substances to egg PC membranes. It was reduced by the presence of cholesterol, but enhanced by the presence of isopropanol, n-butanol, or thymol in the sample solution above a critical concentration of each compound. These and previous observations (8) suggest that a close correlation may exist between the permeability of the membrane and the orientation of the membrane lipids.
The glucose permeation was drastically suppressed by the presence of Ca2+ (10mM) in the sample solution with the membrane containing phosphatidylserine, but was not at all suppressed with the membrane of the egg PC-cholesterol mixture.抄録全体を表示PDF形式でダウンロード (644K) -
Masataka MORI, Satoshi MIURA, Masamiti TATIBANA, Philip P. COHEN1980 年 88 巻 6 号 p. 1829-1836
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーA putative precursor of rat liver ornithine transcarbamylase [EC 2. 1. 3. 3] which was about 3, 400 daltons larger than the subunit of the mature enzyme (36, 000 daltons) was synthesized in a rabbit reticulocyte cell-free system and inununoprecipitated using an antibody against the bovine enzyme and fixed Staphylococcus aureus cells. The mature enzyme of rat liver competed effectively with the putative precursor for interaction with the antibody. Digestion of the putative precursor by S. aureus protease gave a pattern of peptide fragments similar to that of the mature enzyme. A rat liver mitochondrial preparation converted the putative precursor to a polypeptide which comigrated with the mature subunit on sodium dodecyl sulfate/polyacrylamide gels. The “processed” product was recovered in sedimented mitochondria and was no longer susceptible to externally added proteases. These results indicate that the enzyme is synthesized as a larger precursor which may be imported into mitochondria in association with post-translational proteolytic processing to the mature form of the enzyme.抄録全体を表示PDF形式でダウンロード (3045K) -
Tsutomu KAIZU, Yutaka KIRINO, Hiroshi SHIMIZU1980 年 88 巻 6 号 p. 1837-1843
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーBy means of saturation transfer electron spin resonance spectroscopy the rotational motion of spin-labeled Ca2+-dependent ATPase molecules has been investigated for three kinds of preparations of rabbit skeletal muscle sarcoplasmic reticulum: MacLennan's enzyme (purified ATPase preparation), DOPC- and egg PC-ATPase (purified ATPase preparations in which endogenous lipids are replaced with dioleoyl and egg yolk phosphatidylcholine, respectively). The rotational mobility of the enzyme in these preparations is somewhat lower than that in the intact membrane, probably due to the reduced amount of lipids. For all the preparations, however, the Arrhenius plot for rotational mobility showed a break at about 18°C, the same temperature at which a break in the Arrhenius plot for Ca2+-ATPase activity occurs. This result provides further evidence that the break in the Arrhenius plot is not related to a lipid phase transition but to a change in the physical state of the Ca2+-ATPase molecule existing in fluid lipids.抄録全体を表示PDF形式でダウンロード (524K) -
Masatoshi MAKI, Masaaki HIROSE, Hideo CHIBA1980 年 88 巻 6 号 p. 1845-1854
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーPrevious reports have shown that in the cytosol from rat mammary gland, the high affinity binding of glucocorticoid is strongly inhibited by unlabeled progestin and that of progestin is strongly inhibited by glucocorticoid. Experiments were carried out with [3H] dexamethasone and [3H] R5020 to determine whether the binding sites for glucocorticoid and progestin are the same. Thermal inactivation experiments showed that the molecular properties of the [3H]-dexamethasone-binding sites closely resemble those of the [3H] R5020-binding sites. The dissociation constant of the [3H] R5020-receptor complex was almost exactly the same as the inhibition constant of unlabeled R5020 for [3H]dexamethasone-binding sites. The same correlation was observed between the dissociation constant and the inhibition constant of dexamethasone. In addition, no [3H] R5020-binding was observed after saturating the [3H]-dexamethasone-binding sites. These results led us to conclude that common binding sites for [3H] dexamethasone and [3H] R5020 exist in the cytosol from the rat mammary gland. The results of further experiments, including Scatchard analyses and DEAE-cellulose chromatography, strongly suggest that there are at least two classes of [3H] dexamethasone-binding sites, and that one of them binds both glucocorticoid and progestin stably.抄録全体を表示PDF形式でダウンロード (866K) -
Two Distinct α1→3 Specificities of Rabbit Anti-Dextran B1355Mitsuo TORII, Blesila P. ALBERTO, Setsuko TANAKA1980 年 88 巻 6 号 p. 1855-1859
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーRabbit anti-dextran B1355 sera prepared by injecting rabbits with Leuconostoc mesenteroides NRRL B1355 were separated on a Sephadex G75 column into two fractions, one binding and the other not binding to the column. Oligosaccharide inhibition of precipitation of the two fractions with dextran B1355 indicated that both fractions had α1→3 specificity. However, antibodies in the non-binding fraction were shown to be directed against O-α-D-glucopy-ranosyl-(1→3)-O-α-D-glucopyranosyl-(1→6)-D-glucose, while those in the binding fraction were directed against O-α-D-glucopyranosyl-(1→6)-O-α-D-glucopyranosyl-(1→3)-D-glucose. These results are consistent with the proposal of Bhoopalam et al. (Proc. Soc. Exp. Biol. Med. (1979) 161, 430-434) that there are different epitopic groups on this dextran.抄録全体を表示PDF形式でダウンロード (335K) -
Yoshiko KASHIWABARA, Hiroko NAKAGAWA, Genji MATSUKI1980 年 88 巻 6 号 p. 1861-1868
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリー1) The particulate fraction of cultivated murine leprosy bacilli (Mycobacterium lepraemurium, rough colonies of the Hawaiian-Ogawa strain) contained phospholipid deacylating activities with acidic pH optima. It hydrolyzed phosphatidylcholine and phosphatidylethanolamine at similar rates, and phosphatidylinositol oligomannosides more slowly. It also hydrolyzed 1-acyl- and 2-acyl-GPCs (sn-glycerol 3-phosphocholine) more rapidly than phosphatidyl-choline.
2) Ca2+ did not stimulate either diacyl- or monoacyl-hydrolase activity.
Triton X-100 and Emulgen 913 had little influence on the hydrolysis of phosphatidylcholine, but at rather high concentrations inhibited the hydrolyses of 1-acyl- and 2-acyl-GPCs.
Iron ions strongly inhibited the hydrolysis of phosphatidylcholine, but caused little or no inhibition of the deacylations of 1-acyl- and 2-acyl-GPCs.
3) With 1-[stearoyl-14C]phosphatidylcholine and 2-[oleoyl-14C]phosphatidylcholine as substrates, both labeled fatty acid and lysophosphatidylcholine were produced. Labeled fatty acid appeared more rapidly from 2-[oleoyl-14C]phosphatidylcholine than labeled lysophos-phatidylcholine, while labeled lysophosphatidylcholine was produced more than labeled fatty acid from 1-[stearoyl-14C]phosphatidylcholine in the early stage of incubation.抄録全体を表示PDF形式でダウンロード (613K) -
Akio MATSUKAGE, Miwako NISHIZAWA, Taijo TAKAHASHI, Tatsunobu HOZUMI1980 年 88 巻 6 号 p. 1869-1877
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーThe DNA chain elongation mechanisms of mouse DNA polymerases α and β have been analyzed by using denatured DNA with a (dT)n block at the 3'-end as a template in combination with RNA ((rA)12-20) primer. The (rA)12-20-primed DNA product synthesized by DNA polymerase α was 3-5 s in size even after prolonged reaction; instead of a size increase, the number of 3-5 s molecules increased with the reaction time. The size of products was not affected by differences in 3H-labeled substrate (dATP or dTTP), enzyme amount, KCI concentration, or the length of 3'-(dT)n blocks. On the other hand, DNA polymerase β synthesized long DNA products by a highly distributive reaction mechanism. 3-5 s DNA pieces synthesized by DNA polymerase a were not elongated any further by DNA polymerase α, but were converted into long DNA chains by DNA polymerase β. The results imply that DNA polymerase α recognizes the size of the product DNA, and shuts off further elongation.抄録全体を表示PDF形式でダウンロード (706K) -
Masaaki TAGUCHI, Katsura IZUI, Hirohiko KATSUKI1980 年 88 巻 6 号 p. 1879-1882
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーAn abrupt increase of cyclopropane fatty acid (CFA) occurred concomitant with a decrease of the corresponding unsaturated fatty acids in CP78 (rel+) of Escherichia coli at the onset of the stationary growth phase, whereas such variations were slight in CP79 (rel-). When the cells were starved for isoleucine, the CFA content increased in CP78 but not in CP79. The rate of 14C-incorporation from [methyl-14C]methionine into CFAs increased in CP78 about two-fold due to the starvation. The apparent level of CFA synthase also increased due to the starvation. These results indicate that the CFA formation is augmented under stringent control.抄録全体を表示PDF形式でダウンロード (305K) -
Fumi MORITA, Atsushi MATSUMOTO1980 年 88 巻 6 号 p. 1883-1886
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーBinding of divalent metal ions to the g1 subunit isolated from myosin was shown by the difference UV-absorption spectrum. The difference spectrum indicated movement of a tyrosyl residue of g1. The residue responsible for the difference spectrum was assigned to be 180 Tyr.抄録全体を表示PDF形式でダウンロード (250K) -
Yuhachiro YODA, Teruo ISHIBASHI, Akira MAKITA1980 年 88 巻 6 号 p. 1887-1890
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーA glycolipid was isolated from normal lung and lung carcinoma tissues. This glycolipid was identified as the Forssman antigen of pentaglycosyl ceramide by means of chemical and immunological methods. The presence of this antigenic glycolipid was observed in all the tissues examined of adult and embryo lungs, and of lung tumors irrespective of histological type. The extracts of human lung and lung tumors were capable of catalyzing the synthesis of Forssman antigen from globoside.抄録全体を表示PDF形式でダウンロード (1032K) -
Toshisuke KAWASAKI, Yasuko MIZUNO, Tohru MASUDA, Ikuo YAMASHINA1980 年 88 巻 6 号 p. 1891-1894
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーA binding protein which recognizes mannose and N-acetylglucosamine was isolated from mesenteric lymph nodes of rats by affinity chromatography. The isolated binding protein shares some common properties with liver mannan-binding protein: requirement of Ca2+ for the binding and high affinity for mannan. However, these two proteins were distinguishable by their antigenicity and their binding affinity for mannosamine.抄録全体を表示PDF形式でダウンロード (916K) -
Atsushi IKAI1980 年 88 巻 6 号 p. 1895-1898
発行日: 1980/12/01
公開日: 2008/11/18
ジャーナル フリーA statistical analysis shows that the aliphatic index, which is defined as the relative volume of a protein occupied by aliphatic side chains (alanine, valine, isoleucine, and leucine), of proteins of thermophilic bacteria is significantly higher than that of ordinary proteins. The index may be regarded as a positive factor for the increase of thermostability of globular proteins.抄録全体を表示PDF形式でダウンロード (288K)
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