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Volume 69, Issue 1
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Yoshitake MANO1971 Volume 69 Issue 1 Pages 1-10
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe mechanism of increase in the basal rate of protein synthesis in the early cleavage stage of the sea urchin, Pseudocentrotus depresses, was studied. In accordance with previous findings, no increase in the basal rate during incubation was found in cell-free systems and on disruption of cells their rate of synthesis is appeared to be maintained. The increase in the basal rate of synthesis was parallel with the activity of ribosomes in supporting amino acid incorporation, but no correlation was found between the basal rate and the activity of non-particulate fraction in supporting protein synthesis. On fertilization there were sudden parallel increases in the amount of polyribosomes in cells, the amount of informational RNA in the ribosomes, the binding capacity of mtRNA to ribosomes and the polyribosomal activity, expressed as the amount of nascent peptide on polyribosomes. Later, these all increased more gradually, and they were not correlated with the incorporation activity of intact embryos. On sedimentation the polyribosomes were distributed between 200 and 300S. Their peak was gradually displaced toward heavy regions until the end of the first cell cycle and then remained unchanged. The mechanism of increase in the basal rate, the interrelation between the polyribosomes formed in the cyclic and basal phases, and the mechanism controlling three subphases of the basal rate (the lag phase, the first phase and the succeeding phase) are discussed on the basis of these results.View full abstractDownload PDF (791K) -
Cell-free Cyclic Variation of Protein Synthesis Associated with the Cell Cycle in Sea Urchin EmbryosYoshitake MANO1971 Volume 69 Issue 1 Pages 11-25
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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II. Susceptibility of Tryptophan to the Riboflavin-sensitized Photooxidation in the Presence of AdenineKihachiro UEHARA, Tadashi MIZOGUCHI, Kenichi KISHIDA, Shigeyasu MANNEN1971 Volume 69 Issue 1 Pages 27-33
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAdenine remarkably accelerates the riboflavin-sensitized photoinactivation of sweet potato β-amylase [EC 3. 2.1. 2], but guanine has no effect. Studies on the photooxidation of native and alkali-denatured amylases and free amino acids with riboflavin in the presence and absence of adenine show that the oxidation of cysteine and methionine are accelerated by the addition of adenine, regardless of whether they are contained in the enzyme molecule or present free, and that some tryptophan residues in β-amylase are susceptible to the photooxidation and their degradations are accelerated by the addition of adenine probably because of their specific configurations in the enzyme molecule. The data also suggest that, at the photoinactivation of native β-amylase, the degradation of susceptible tryptophans are accelerated first by addition of adenine before the degradation of other amino acids, indicating their importance for the enzymatic activity.View full abstractDownload PDF (533K) -
III. Properties of Mitochondria from Mycelia Grown in the Presence of Antimycin AMasao KAWAKITA1971 Volume 69 Issue 1 Pages 35-42
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMitochondria were prepared from mycelia of Aspergillus oryzae grown in the presence of antimycin A as reported previously. The oxygen uptake of the mitochondria with Krebs cycle intermediates as substrates was insensitive to antimycin A and cyanide. Phosphorylation was coupled to the drug-resistant respiration, thus confirming the idea that antimycin A-resistant growth is due to the properties of the mitochondria. However, lower values of the P/O ratio were obtained with several substrates, suggesting that there might be some defect in the respiratory system. Normal cytochrome oxidase [EC 1.9.3. 1] was present in the mitochondria, as shown by spectrophotometry and by cyanide-sensitive oxidation of ascorbate plus tetra-methyl-p-phenylenediamine, although the enzyme did not seem to act on the oxidation of Krebs cycle intermediates. Cytochrome b was in the reduced form even in an aerobic suspension of the mitochondria and was hardly oxidized by ferricyanide. It appeared to be inactivated in situ. Presence of an alternate pathway of electron transport insensitive to antimycin A and cyanide was suggested, but its chemical nature remained to be studied. No indication of formation of a new cytochrome component was obtained.View full abstractDownload PDF (614K) -
Kinji KAKIUCHI, Yuji KOBAYASHI1971 Volume 69 Issue 1 Pages 43-52
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe description of some physico-chemical properties of soluble collagen extracted from chicken leg tendons in solution have been provided. The sedimentation equilibrium experiments were carried out. The molecular weight of soluble collagen was found to be 231, 000. When soluble collagen was treated with guanidine hydrochloride to destroy collagen structure effectively, its molecular weight was reduced to one-third, 76, 000. Furthermore, the molecular weight of heat denatured collagen was found to be 18, 500, which is a value of one-twelfth of that of native collagen in an aqueous solution.
For the soluble collagen the concentration dependence of apparent molecular weights, sedimentation coefficients, and viscosities, suggest that the collagen molecule has a rod shape, because the second virial coefficients are larger than that of globular protein molecules of the same molecular weights.
Data of the heat denatured collagen require the consideration of an association mechanism. It has become possible to calculate the dimerization constant and to assign the sedimentation coefficients for dieter and monomer.
The length of the collagen molecule which was obtained with hydrodynamic investigations agreed to our results of electron microscopy.View full abstractDownload PDF (2129K) -
I. Absorption, Excretion and Tissue Distribution in RatsTakeshi FUJITA, Shigeharu TANAYAMA, Yoshihiro SHIRAKAWA, Ziro SUZUOKI1971 Volume 69 Issue 1 Pages 53-61
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAbsorption, blood level, tissue distribution and elimination were studied on rats after the administration of 14C-labeled ubiquinone-7. Blood radioactivity attained its maximum at 2 hr after the oral dose of a hydrogenated castor oil solution of ubi-quinone-7 and gradually declined thereafter, whereas the peak level reached at d hr after administration of corn oil solution. Following the intravenous injection, blood radioactivity declined in three phases with half-lives of 2/3, 2 and 22 hr, respectively. Orally ingested ubiquinone-7 was absorbed unchanged exclusively via the lymphatic route. After absorption, the compound was located mainly in liver and excreted into intestinal tract with bile. A part of the radioactivity excreted in bile was resorbed and the remainder excreted in stool together with unabsorbed ubiquinone-7. Thus, 73% of the ingested radioactivity was recovered from urine, feces, expired air and gastrointestinal contents during the first 72 hr, of which the feces accounted for 62%. The fecal excretion was therefore the main route for elimination. All of the data was treated with the simulation technique by analog computer and a metabolic model to fit the observed events was proposed.View full abstractDownload PDF (580K) -
II. Isolation and Identification of Metabolites in the Urine, Liver, Bile and FecesTakeshi FUJITA, Shigeharu TANAYAMA, Ziro SUZUOKI1971 Volume 69 Issue 1 Pages 63-71
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe metabolic conversion of methoxy-14C-labeled ubiquinone-7 was investigated in the rat following intravenous injection. From urine two radioactive metabolites were isolated and identified. The major metabolite is a new compound whose structure is 2, 3-dimethoxy-5-methyl-6-(3'-carboxypropyl-3'-methyl)-l, 4-benzoquinone (compound B) whereas the other one is γ-lactone of 2, 3-dimethoxy-5-methyl-6-(5'-carboxypentyl-3'-hydroxy-3'-methyl)-l, 4-benzoquinone (compound A). Compound B accounted for about a half of the urinary metabolites and compound A a quarter. Both metabolites were excreted as conjugates into urine. About 90_??_ of the hepatic radioactivity was identified as unchanged ubiquinone-7. Chromatographic examinations indicated the occurrence of compounds A and B in bile and feces, presumably as conjugates. The main biotransformation of ubiquinone-7 was thus proved to be oxidative shortening of the side chain. The chain with 7 isoprenoid units was eventually degraded to 3-carboxy-3-methylpropyl group in compound B via 5-carboxvpentyl-3-hydroxy-3-methyl group in compound A, possibly due to β-oxidation of the latter. Metabolic conversion of ubiquinone-7 to ubiquinone-9 or ubiquinone-l0 was not recognized in the present studies.View full abstractDownload PDF (580K) -
Gotaro TODA, Hikaru KOIDE, Yawara YOSHITOSHI1971 Volume 69 Issue 1 Pages 73-82
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe effect of beryllium on K+-activated phosphatase was investigated. Preincubation of the enzyme preparation with BeCl2 in the presence of Mg2+ caused reduction of K+-activated phosphatase activity, while preincubation with BeCl2, only caused no reduction. Addition of K+, Rb+ or NH4+ but not Li+ with Mg2+ and BeCl2 during preincubation increased the inhibition rate. Under the same conditions, Na+ decreased the rate of inhibition. This protective effect of Na+ was greatest in the absence of K+ and decreased with increase in the concentration of K+.
The effects of cations on the inhibition of K+-activated phosphatase by beryllium were compared with their effects on that of (Na++K+)-activated ATPase [ATP phosphohydrolase, EC 3.6. 1.3] and results suggested that there is a close linkage between these two enzyme activities. It also seemed that K+ interacted with the enzyme even in the absence of p-nitrophenyl phosphate and that this interaction was intimately related with the activation of K+-activated phosphatase by K+. Results of kinetic analyses of the activation of K+-activated phosphatase by K+ and the effect of ouabain on the inhibition rate indicated that there are at least two different ways of interaction of K+ with enzyme.View full abstractDownload PDF (772K) -
Kunihiko SAITO, Kiyomi MUKOYAMA1971 Volume 69 Issue 1 Pages 83-90
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. Diglucosyldiglyceride from B. cereus was purified on columns of silicic acid and florisil.
2. The structure proposed was glucosyl-(1-.6)-glucosyl-(1-1)-diglyceride.
3. The crystalline lipase [EC 3.1.1.3] of Rh. delemar, which was known to attack the terminal ester linkage of the “synthetic” triglycerides, liberated from the diglucosyldiglyceride mainly the higher members of the constituent fatty acids, i.e., br-C15, br- and n-C16 and br-C17 acids with a formation of diglucosylmonoglyceride.
4. The constituent fatty acids of the diglucosylmonoglyceride, esterified at C-2 position, were mainly br-C13, br-C14 and br-C15.View full abstractDownload PDF (4358K) -
Properties of Two Types of Copper Ions in the MoleculeNobuo MAKINO, Yasuyuki OGURA1971 Volume 69 Issue 1 Pages 91-100
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS(1) The molecular weight of laccase [EC 1. 10. 3. 2, p-diphenol: oxygen oxidoreductase] from the latex of Rhus venicifera was re-estimated by the method of sedimentation equilibrium and found to be 1.04×105, taking the partial specific volume as 0.734ml/mg. It was confirmed that as reported previously (1), lactase contains 4.0g-atom of copper per mole of protein.
(2) The copper ions in laccase were titrated with hydrogen peroxide as an oxidant and with ascorbate as a reductant, measuring the absorbance changes at 615mμ and 330mμ under anaerobic conditions. The profiles of the titration curves measured at these two wave-lengths. differed. It was concluded that these two absorption bands were due to different species of copper ions in lactase. It was estimated that there was one copper ion, Cu2+(615), with an absorption band at 615mμ and two or three copper ions, Cu2+(330), with an absorption band at 330mμ in the molecule.
(3) Cu(615) and Cu(330) seemed to be in oxidation-reduction equilibrium, the oxidation-reduction potential of Cu(615) being lower than that of Cu(330). The redox potential difference, E0330-E0615, was estimated to be+45 mV at pH 7.0 and 25°C.
(4) On oxidative titration of the reduced enzyme with molecular oxygen, the amounts of the cupric forms of Cu(615) and Cu(330) increased almost linearly with increase in the concentration of molecular oxygen added. This suggests that the fully reduced enzyme is spontaneously oxidized with molecular oxygen by a four-electron transfer reaction.View full abstractDownload PDF (790K) -
I. Isolation of Sheath from Pyocin R by Alkali Treatment and Its PropertiesChie YUI1971 Volume 69 Issue 1 Pages 101-110
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. Pyocin R has been shown to be degraded into contractile sheath and other smaller subunits by treatment with 0.1N NaOH.
2. Alkali treated pyocin R was separated into two peaks (Peaks I and II) by sucrose density gradient centrifugation. Upon centrifugation contractile sheath formed the main peak (Peak I). Recovery of the sheath was more than 95%.
3. Disc electrophoresis of subunits of Peaks I and II showed that Peak I contained no significant contamination of Peak II and that Peak I contained the whole sheath.
4. Isolated sheath was homogeneous, electron microscopically, electrophoretically, immunochemically, and from the results of ultracentrifugation.
5. The particle weight of sheath was 7.2×106 daltons by the meniscus depletion method. 6, s°20, w was 89S.
7. Amino acid composition of sheath was analyzed.View full abstractDownload PDF (3509K) -
Tatsuro KOIKE, Tsuneko UCHIDA, Fujio EGAMI1971 Volume 69 Issue 1 Pages 111-117
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. The synthetic reactions by a novel ribonuclease, RNase U2 [ribonucleate purinenucleotido-2'-transferase (cyclizing)] were studied. The yield of adenylyl-(3', 5')-uridine amounted to 37% when adenosine 2', 3'-cyclic phosphate (A cyclic-p) and uridine were incubated with RNase U2. Furthermore 58% of A cyclic-p remained unchanged. RNase U2 was, thus, proved to be a useful tool for the synthesis of oligonucleotide.
2. The yield of ApN was influenced by various factors, such as temperature, in-cubation time, pH, enzyme concentration and phosphate acceptors. It was found that a lower temperature gave a larger amount of the product, reducing the competing hydrolytic activity. The yield of ApN decreased according to the type of phos-phate acceptors in the following order: cytosine>uridine>glyoxal G cyclic-p, inosine>adenosine> 2'(3')-cytidylate>2'(3')-guanylate.
3. ApG cyclic-p, a substrate of RNase N, [EC 2. 7. 7. 26] for the synthesis of oligo ApGp, was also prepared by RNase U2 with 10% yield.
4. Oligoadenylic acids consisting of two to five adenylyl residues were synthesized by RNase U2 and fractionated by DEAE-Sephadex column chromatography in the presence of 7M urea. The yield of polymerized products was about 22% including ApA cyclic-p (14.1%), ApAp (2.7%) and trimer (5.4%).View full abstractDownload PDF (484K) -
IV. Hydrolyses of p-Nitrophenyl Acetate with Copoly [L-Ser (or L-Thr), L-Asp (or L-Glu)] and Copoly [L-Ser (or L-Thr), L-Asp (or L-Glu), L-Ala]Junzo NOGUCHI, Hiroyuki YAMAMOTO1971 Volume 69 Issue 1 Pages 119-126
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe catalytic hydrolyses of p-nitropheny acetate (NPA) by the cooperative interaction between the alcoholic hydroxyl group of the seryl (or threonyl) residue and the carboxyl group of the aspartyl (or glutamyl) residue were studied. With aspartyl copolymers, the hydrolytic activity toward NPA increased with increase of pH, irrespective of the presence of an alanyl component. On the other hand, glutamyl copolymers showed remarkable difference in the hydrolytic activity at different pH values depending on whether the alanyl residue was or was not present in the molecule. The presence of an alanyl residue in the glutamyl copolymer changed the pH activity curve from a simple quadratic curve to bell-shaped one.
With alanyl copolymers a plot of NPA hydrolysis against temperature had a bell-shaped profile at 30-60°C, while that of copolymers without alanine increased steadily with temperature.
The aspartyl copolymer containing alanine showed an interesting phenomenon of irreversible coagulation in aqueous solution on heating. Thus the L-alanyl residue seems to contribute to the formation of a specific active site in the copolymer molecule. The apparent Vmax's of all the copolymers were in the order of 10-6M/min per mg/ml of copolymer and the apparent Km's were 10-2-10-3M.View full abstractDownload PDF (548K) -
Terumi SAITO, Akio YOSHIMOTO, Kenkichi TOMITA1971 Volume 69 Issue 1 Pages 127-135
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMalic enzyme [malate: NADP oxidoreductase (decarboaylating) EC 1. 1. 1. 40] was purified about 900-fold from the liver of hyperthyroid rats maintained on diet containing 2% desiccated thyroid for 5 days. The pH optimum of the purified enzyme was 7.4 and the apparent Km, values for malate, NADP and Mg2+ were 0.46mM, 5.4μM and 0.5mM, respectively.
Malic enzyme purified from the liver of hyperthyroid rat was indistinguishable from that from normal rat liver with respect to its electrophoretic mobility on polvacrylamide gel, pH optimum and apparent Km, values for malate and NADP.
Rat liver malic enzyme has some properties in common with pigeon liver malic enzyme, such as its pH optimum at 7.4 and its molecular weight (ca. 250, 000) estimated by gel filtration on Bio-Gel P-300. However, the rat liver enzyme differs from the pigeon liver enzyme in its stabilities and in the effects of various inhibitors. Both malic enzymes were unstable when stored in the presence of 1mM mercaptoethanol, but in its absence the rat liver enzyme was quite stable for a long period, while the pigeon liver enzyme was not. Rat liver enzyme was inhibited by the same inhibitors as pigeon liver enzyme such as heavy metal ions, iodoacetate and p-chloromercurihenzoate, but was only partially inhibited at concentrations which completely inhibited the pigeon liver enzyme.View full abstractDownload PDF (636K) -
Hidehiko KUMAGAI, Hideaki YAMADA, Haruo SUZUKI, Yasuyuki OGURA1971 Volume 69 Issue 1 Pages 137-144
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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I. Preparation Using ChymotrypsinMasahiko ONODERA, Koichi YAGI1971 Volume 69 Issue 1 Pages 145-153
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn enzymatically active subfragment was isolated from heavy meromyosin and also from myosin aggregate after the chymotryptic digestion at low temperature. The adenosine-triphosphatase [EC 3. 6. 1. 3] activity in the presence of Ca2+ was 1.0μmole of P, liberated per mg protein per min. The molecular weight of this subfragment was about 1.0×105. The two properties were indistinguishable from those of sub-fragments prepared by using other proteolytic enzymes. In the presence of F-actin, however, the adenosine-triphosphatase activity of this subfragment was considerably higher than that of other subfragments. Actin polymerization was accelerated by this subfragment as heavy meromyosin does, while it was not accelerated by the subfragment prepared by the tryptic digestion.View full abstractDownload PDF (604K) -
Nozomu OSHINO, Yoshio IMAI, Ryo SATO1971 Volume 69 Issue 1 Pages 155-167
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSOn addition of NADPH to rat liver microsomes cytochrome b5 assumes a steady-state reduction level, based on a balance between its reduction by NADPH and its aut-otiidation. Initiation of fatty acid desaturation by adding stearoyl-CoA (stearyl CoA) results in a rapid shift of the NADPH-supported steady state of the cytochrome in favor cf more oxidation, and this shift is intensified by partially inhibiting microsomal NADPH-_??_specific flavoprotein by HgCl2. This suggests that increased utilization of reducing equivalents for desaturation is accompanied by a stimulation of reoxidation of cvtochrome b5. Actually, the magnitude of stearyl CoA-induced shift is roughly proportional to the fatty acid desaturation activity of the microsomes employed. Moreover, this shift is interfered with by cyanide which inhibits a terminal component (“cyanide-sensitive factor”) of the desaturation system.
Since the reduction of microsomal bound cytochrome b5 by NADH is much faster than the autoxidation of the cytochrome and the overall desaturation reaction, NADH causes complete reduction of cytochrome b5 and no change in the reduction level is observed on addition of stearyl CoA. However, when NADH-cytochrome b5 reductase is strongly inhibited by PCMS, stearyl CoA does lower the steady-state reduction level of cytochrome b5 in NADH-treated microsomes. Stearyl CoA also stimulates the oxidation of cytochrome b5 observable on exhaustion of the NADH added, and this stimulation is again prevented by cyanide.
With microsomes from which cytochrome b5 has been removed to various extents by mild proteolytic digestion, the desaturation of stearyl CoA supported by ascorbate as electron donor is dependent on the content of remaining cytochrome b5.
It is concluded that cytochrome b5 in liver microsomes acts as an intermediary electron carrier which passes reducing equivalents from NADH, NADPH and ascorbate to the cyanide-sensitive factor where fatty acid desaturation per se probably takes place.
Microsomes prepared from rat epididymal adipose tissue contain a significant amount of cytochrome b5, which plays a similar role in fatty acid desaturation.View full abstractDownload PDF (4892K) -
Nozomu OSHINO, Ryo SATO1971 Volume 69 Issue 1 Pages 169-180
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSVarious phenols, notably p-cresol, and two non-phenolic compounds have been found to stimulate the aerobic reoxidation of cytochrome b5, reduced by NADH, in rat liver microsomes having a high activity of stearyl CoA desaturation. This stimulation is accompanied by simultaneous increases in the oxidation of NADH and consumption of molecular oxygen. The phenols added also seem to be oxidized. Evidence has been obtained that cytochrome b5 located in a microsomal vesicle undergoes oxidation independently of that present in the other vesicles during the phenol-stimulated process. As in the similar stimulation of cytochrome b5 reoxidation by stearvl CoA, the phenol effect is inhibited by cyanide. The magnitude of phenol effect can be correlated with the stearyl CoA desaturation activity of the microsomes; it is negligible in liver microsomes from fasted rats, but can be induced profoundly by refeeding the animals on a high-carbohydrate diet. The phenol effect is also detectable in adipose tissue microsomes, which show a high desaturation activity. It is concluded that the phenols interact with the cyanide-sensitive factor, the terminal enzyme of the microsomal desaturation system, resulting in an increased utilization by oxygen of electrons of reduced cytochrome b5. Since the phenol effect is depressed by low concentrations of stearyl CoA, the cyanide-sensitive factor seems to react with stearyl CoA in preference to the phenols.View full abstractDownload PDF (2552K) -
Masatake OHNISHI1971 Volume 69 Issue 1 Pages 181-189
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1) The inhibition by β-cyclodextrin (cyclomaltoheptaose), maltose, and glucose of the hydrolysis of amylose by bacterial liquefying α-amylase [EC 3. 2. 1. 1] was studied kinetically. The type of the inhibition was competitive for all the inhibitors employed, and the inhibitor constant K_??_'s determined were 0.018M for β-cyclodextrin, 0.072M for maltose and 0.38M for glucose.
2) The number of exposed tryptophan residues was estimated by solvent pertur-bation technique, in which various organic perturbants were used. It was found that 8 to 9 tryptophan residues are exposed although the enzyme has 15 tryptophan residues in total.
3) Difference spectra of the enzyme in the presence of β-cyclodextrin, maltose, or glucose were measured to investigate their specific binding with the enzyme. In the presence of β-cyclodextrin, a characteristic difference spectrum was observed. The difference spectrum was attributed to one tryptophan and one tyrosine residues on the basis of the analyses of its shape and magnitude. On the basis of the difference-spectral titration at 291-293 mμ, the dissociation constant of β-cyclodextrin-enzyme complex was determined to be 0.018M, which was in good agreement with Ki value obtained from kinetic studies. Maltose and glucose, however, did not show any characteristic difference spectrum other than that arising from common solvent perturbation, although they formed complexes with the enzyme as inferred from their competitive type of inhibition.
4) The comparison of Ki values for the three competitive inhibitors with each other indicated that β-cyclodextrin covered an additional area (subsite) at the active site of the enzyme and that the area was not covered either by glucose or by maltose. By combination of the results obtained by means of kinetic and difference-spectral techniques, it was suggested that one tryptophan and one tyrosine residues are located in the subsite of the enzyme, in which the subsite is covered by β-cyclodextrin but not by maltose or glucose.View full abstractDownload PDF (662K) -
Sadato YABUKI, Motohiro FUKE, Akiyoshi WADA1971 Volume 69 Issue 1 Pages 191-207
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSRemarkable fine structures have been observed in the melting and renaturation curves of phage lambda DNA with our automatic recording apparatus of heatingcooling curves of UV absorbance. The fine structures are thought to originate from the unusual internal heterogeneity of the base sequence of the DNA molecule of bacteriophage lambda.
A new method for the analysis of the fine structures in the melting and renatu-ration curves is described. Using this method, the molecular process of melting of phage lambda DNA and the detail of the molecular ensemble at an intermediate stage of denaturation are analyzed.View full abstractDownload PDF (1372K) -
Takashi MURACHI, Tokiko MIYAKE, Keiko KATO1971 Volume 69 Issue 1 Pages 209-217
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSOn chemical modification of hen egg-white lysozyme [EC 3. 2. 1. 17] with diisopropylphosphorofiuoridate (DFP) diisopropylphosphoryl (DIP) enzyme was obtained. The spectral characteristics of various DIP-lysozyme preparations obtained under different conditions were studied. The spectral studies included measurements of the ultra-violet difference spectra of DIP-lysozyme minus lysozyme, the change in the spectra of DIP-lysozyme at alkaline pH, spectrophotometric titration curves for ionizable phenolic hydroxyl groups, measurement of optical rotatory dispersion in the far ultraviolet region, and measurement of circular dichroism spectra in the range of 200-320mμ. Modification of the tyrosyl residues in DIP-lysozyme was demonstrated by the changes in the absorption spectra of DIP-lysozyme at neutral and alkaline pH values and also by the changes in its circular dichroism spectra at an alkaline pH. One or slightly more than one tyrosyl residue per molecule was found to have been modified by DFP at pH 10.2-11.0. However, when the reaction of lysozyme with DFP was carried out in the presence of 3M or 5M guanidine hydrochloride, the number of modified tyrosyl residues increased markedly. A DIP-lysozyme specimen in which nearly all the three tyrosyl residues were modified showed a significant decrease in ordered conformation as judged by its optical rotatory dispersion and circular dichroism spectra. Other DIP-lysozyme samples tested seemed to retain a conformation indistinguishable from that of native lysozyme.View full abstractDownload PDF (639K) -
Isao KATSURA, Haruhiko NODA1971 Volume 69 Issue 1 Pages 219-229
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMyosin forms at physiological KCl concentration, filaments which resemble native thick filaments of a sarcomere. An extensive survey on filament length changing various conditions was carried out by both flow birefringence and electron microscopy. The most effective condition on filament length was the speed of lowering of KCl concentration, whereas protein concentration was not effective. The change of turbidity caused by association reaction was measured with a stopped flow apparatus, and the early reaction fitted with an exponential curve. The apparent half time was inversely proportional to the square of protein concentration. The width of the filament calculated from the length in electron micrographs and was s°20, w was 125 Å and independent of length when the length was longer than 0.61μ. The degree of association was about 200 per 1μ. It is difficult to explain the mechanism of asso-ciation using a usual nucleation-and-growth model without modification.View full abstractDownload PDF (1442K) -
Carbon Monoxide Evolution during Auto- and Enzymatic Oxidation of PhenolsSadao MIYAHARA, Hitoshi TAKAHASHI1971 Volume 69 Issue 1 Pages 231-233
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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Yoichi TAMAI, Shigeko MATSUKAWA, Mei SATAKE1971 Volume 69 Issue 1 Pages 235-238
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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Kosuke MORIKAWA, Yoichi IITAKA, Masamichi TSUBOI, Susumu NISHIMURA1971 Volume 69 Issue 1 Pages 239-241
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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Yasuhiro ANRAKU1971 Volume 69 Issue 1 Pages 243-245
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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Shigeru KUROOKA, Kanoo HOSOKI, Yoshio YOSHIMURA1971 Volume 69 Issue 1 Pages 247-249
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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Tokuji IKENAKA, Susumu TSUNASAWA, Takehiko KOIDE1971 Volume 69 Issue 1 Pages 251-253
Published: January 25, 1971
Released on J-STAGE: November 18, 2008
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