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Volume 78 (1975)
- Issue 6 Pages 1113-
- Issue 5 Pages 863-
- Issue 4 Pages 641-
- Issue 3 Pages 435-
- Issue 2 Pages 247-
- Issue 1 Pages 1-
Volume 78, Issue 3
Displaying 1-24 of 24 articles from this issue
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Takahisa SHINOMIYA, Jiro KOYAMA1975 Volume 78 Issue 3 Pages 435-441
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe intradermal catabolism of antibodies injected in guinea pigs to provoke skin reactions was studied using 125I-labeled guinea pig IgG1 and IgG2 anti-ovalbumin antibodies. Disappearance of both the IgG1 and IgG2 antibodies from injected sites was accelerated by intravenous injection of the antigen. The antigen-antibody complexes produced in vitro were also catabolized more rapidly than free antibodies, when estimated using 125I-labeled antibodies. On the other hand, the catabolism of normal IgG2 was not influenced by local anaphylactic reaction elicited by IgG1 antiovalbumin antibody coexisting at the sites. Therefore, the enhanced catabolism of antibodies on challenge was not caused by increased vascular permeability due to anaphylactic reactions, but by more rapid elimination of immune complexes formed at the sites. The Fc parts of IgG1 and IgG2 antibodies played an essential role in the enhancement of catabolism since the catabolism of the F(ab')2 fragments was not accelerated by complex formation with ovalbumin, but rather reduced.View full abstractDownload PDF (524K) -
The Enzymic Electric Cell MethodTatsuhiko YAGI, Masako GOTO, Kenichi NAKANO, Keisaku KIMURA, Hiroo INO ...1975 Volume 78 Issue 3 Pages 443-454
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA new assay method for hydrogenase [EC 1. 12. 2. 1] based on the enzymic electrode reaction of H2-H+ equilibrium has been established. The method is based on the experimental fact that the short-circuit current of the electric cell composed of an electrode with hydrogenase and methylviologen as the mediator of H2-H+ equilibrium and a saturated calomel electrode as the counter electrode, is practically proportional to the amount of hydrogenase in the cell. The new method is referred to as the “enzymic electric cell method.”
This technique has applications not only to routine activity assay but also to the direct determination of the time course of enzyme denaturation, which has not previously been possible.View full abstractDownload PDF (822K) -
Yuzo YOSHIDA, Hiroshi KUMAOKA1975 Volume 78 Issue 3 Pages 455-468
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe spectral changes of cytochrome P-450 caused by the addition of small molecules to liver microsomes were investigated precisely and the following conclusions were reached.
1. The Type I spectral change was entirely due to the interaction of the cytochrome with a hydrocarbon residue in a ligand. To induce the modified Type II spectral change, the presence of a hydroxyl group in a ligand was required. Compounds which contain a basic amino group induced the Type II spectral change.
2. The Type I spectral change was caused by the interaction of a ligand with the 419-nm form of cytochrome P-450, with its concomitant conversion to the 394-nm form. Whereas, compounds inducing modified Type II spectral change interacted with the 394-nm form of the cytochrome. In this case, however, the 394-nm form was not converted back to the 419-nm form but was converted to a new state showing an absorption peak at 416 nm. The Type II spectral change-inducing interaction of a ligand with the cytochrome could occur with all forms of the cytochrome.
3. Both Type II and modified Type II compounds bound to the cytochrome at heme iron, and converted the cytochrome into modified ferrihemochromes. On the other hand, the Type I interaction occurred in a protein moiety of the cytochrome, and probably caused a conformational change of the cytochrome accompanied either by weakening of the internal ligand interaction or by displacement of the ligand with another one having a weaker field at the heme iron.
4. Type I and each of other two types of binding of compounds with cytochrome P-450 could occur simultaneously.View full abstractDownload PDF (1134K) -
Effects of Temperature and Citrate AnionsSachiko TSUDA, Akio TOMODA, Shigeki MINAKAMI1975 Volume 78 Issue 3 Pages 469-474
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe intracellular pH (pHi) of red cells stored in acid citrate dextrose (ACD) medium was estimated by the 5, 5'-dimethyloxazolidine-2, 4-dione (DMO) method. The initial pHi at 4° was about 7.6 and was higher than the extracellular pH (pHe) at 4°. During storage, both pHi and pHe decreased, but the former was always higher than the latter and the former decreased more slowly than the latter. The high pHi of ACD blood was a results of the temperature at which the pHe and the pHi were measured (4°) and the presence of citrate anions in the medium, and could be explained by application of the Donnan-Gibbs equilibrium. ATP and 2, 3-diphosphoglycerate (DPG) were well-maintained in heparinized blood when it was acidified and pHe and pHi at 4° were both about 7.4, which suggests that improvement of blood preservation may be attained by suitable adjustment of the pHi and pHe of the blood.View full abstractDownload PDF (466K) -
I. Patterns of the Rhythms in Various Regions of the Small IntestineMasayuki SAITO, Eiko MURAKAMI, Teruo NISHIDA, Yoshiki FUJISAWA, Masami ...1975 Volume 78 Issue 3 Pages 475-480
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe activities of the digestive enzymes, maltase [EC 3. 2. 1. 20], sucrase [EC 3. 2. 1. 26], trehalase [EC 3. 2. 1. 28], leucine aminopeptidase [EC 3. 4. 11. 1], and alkaline phosphatase [EC 3. 1. 3. 1] were measured in various regions of the small intestine of rats. The activities of all these enzymes were much higher in the jejunum than in the ileum, and in the distal regions of the ileum no sucrase, trehalase or alkaline phosphatase activity was detected. In the jejunum, the activities of all the enzymes tested exhibited clear circadian variations with the highest activity at 0000-0400h and the lowest at 1200h when the rats were fed ad libitum. In the ileum, maltase and sucrase also exhibited circadian variations, but the amplitude of the rhythm was smaller than that in the jejunum. Trehalase and alkaline phosphatase did not show any circadian variation in the ileum. Leucine aminopeptidase showed a circadian variation in the ileum with the same amplitude as in the jejunum. The phase of the circadian variations shifted about half a day when the rats were fed in the daytime, but the amplitude of the rhythm did not change.View full abstractDownload PDF (479K) -
Hiroyuki SUMI, Nobuo IZUMIYA, Mutumi MURAMATU1975 Volume 78 Issue 3 Pages 481-484
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn immunoadsorbent-antibody (egg albumin-Sepharose-antibody) column was found to be suitable for the rapid separation of Cl-esterase from normal human serum. About 1.54mg of Cl-esterase, with a specific activity of 447 units/mg was obtained in over 80% yield from 20ml of human serum.View full abstractDownload PDF (306K) -
Masashi HIRAI, Tadashi ASAHI1975 Volume 78 Issue 3 Pages 485-492
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSTwo RNases in bound forms associated with the microsomal membrane and with the ribosomes or unknown particles in pea root tissue were solubilized by subjecting the membrane to sonic oscillation in the presense of EDTA and KCl and by treating the particles with EDTA, respectively. The RNases were then purified by DEAE-cellulose and Sephadex G-75 column chromatographies. The elution profiles of RNases from the columns were very similar. No significant differences were observed in their electrophoretic mobilities in polyacrylamide gels, in molecular weight, in activation by inorganic ions, urea or phospholipid micelles or in the dependence of their activities upon pH. The purified RNases were not different from the bound enzymes as regards activation by inorganic ions and urea and the dependence of the activity upon pH. Triton X-100 stimulated the activity only if RNase was in a bound form associated with the microsomal membrane. We propose that the two RNases may be the same molecular species and differ only in the form of association with intracellular structures.View full abstractDownload PDF (559K) -
XII. Investigation of the Active Site of Taka-amylase A by Examining the Properties of p-Phenylazobenzoyl Taka-amylase AKaoru OMICHI, Shigehiro KASAI, Yoshio MATSUSHIMA1975 Volume 78 Issue 3 Pages 493-498
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. When p-phenylazobenzoyl Taka-amylase A (PhAB-TAA) was incubated at pH 6.5 with hydroxylamine for 3hr at 20°, some of the p-phenylazobenzoyl residues that had been introduced into Taka-amylase A (TAA) [1, 4-α-D-glucan glucanohydrolase, EC 3. 2. 1. 1, Aspergillus oryzae] were liberated as a hydroxamic acid, and the activity pattern of PhAB-TAA changed to that of intact TAA. This result suggested that the p-phenylazobenzoyl residues liberated had been bound to the tyrosyl residue located near the active site in the enzyme.
2. The transferase action of TAA or PhAB-TAA was studied using phenyl a-malto-side as a substrate and maltotriitol as an acceptor. Unlike intact TAA, PhAB-TAA was not able to transfer the maltose residue to maltotriitol, and this suggested that the p-phenylazobenzoyl residue was located near one of the aglycone-binding subsites, causing steric hindrance.View full abstractDownload PDF (450K) -
Shogo SHIKATA, Kazutosi NISIZAWA1975 Volume 78 Issue 3 Pages 499-512
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn enzyme extract from Cellulase-Onozuka, a commercial product of Trichoderma viride, was fractionated by Amberlite CG-50 column chromatography into three cellulase [EC 3. 2. 1. 4] groups, peaks I to III. A novel enzyme, which has both β-gluco-sidase [EC 3. 2. 1. 21] and exo-carboxymethyl-cellulase (exo-CMCase) properties, was obtained from peak III by extensive purification through consecutive column chromatography. The enzyme was homogeneous on ultracentrifugation, SDS-gel and cellulose acetate film electrophoreses and molecular sieve chromatography on Bio-Gel P-150. The molecular weight of this enzyme was estimated to be 53, 000. The enzyme appeared to release cellobiose residues one by one from the nonreducing end of higher cellooligosaccharides and CM-cellulose (CMC), but to release glucosyl residues from reduced cellotriose and β-cellobioside, resembling a β-glucosidase in this respect. Furthermore, this exo-CMCase also attacked xylan exo-wise to produce xylobiose molecules one by one, but it scarcely attacked insoluble cellulose, except for a cellodextrin apparently rich in amorphous structure.View full abstractDownload PDF (4474K) -
Eiji SHIMADA, Go MATSUMURA1975 Volume 78 Issue 3 Pages 513-517
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe intrinsic viscosity ([η]) and the molecular weight (M) by sedimentation equilibrium were determined for hyaluronic acids of low (M=104-7.2×104) and high (M=3.1×105-1.5×106) molecular weights. Double logarithmic plot of [η] against M gave different lines for the two groups. The relationship between [η] and M was [η]=3.0×106×M1.20 for the former and [η]=5.7×10-4×M0.76 for the latter group. The molecular weight at the point of intersection of the two lines was about 1.5×105.
The rheological behavior of the hyaluronic acids below M=2.1×104, for which the value of reduced viscosity was independent of concentration, was different from that of the hyaluronic acids above M=5.7×104, for which the value of reduced viscosity increased with concentration.View full abstractDownload PDF (354K) -
VI. Crystallization and Some Properties of D-Erythrulose Reductase from Beef LiverKihachiro UEHARA, Tsuyoshi TANIMOTO1975 Volume 78 Issue 3 Pages 519-526
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSD-Erythrulose reductase of beef liver was crystallized from ammonium sulfate solution at pH 8.17. The crystals are needle-shaped. The enzyme protein contains 851 amino acid residues per mole of the enzyme: Lys28, His11, Arg52, Asp79, Thr58, Ser56, Glu68, Pro20, Gly80, Ala107, Val112, Met24, Ile31, Leu88, Tyr7, Phe22, Trp4, and Cys4. The enzyme is inactivated by exposure to temperatures below 12°. The inactivation is accelerated by increasing the salt concentration and decreasing the enzyme concentration. The pH of the medium also has a pronounced effect, and maximum stability of the enzyme is obtained at pH 8.5. NADP+ protected the enzyme from cold inactivation at all stages of the process and also afforded protection against inactivation by heat and pH. The cold inactivation of the enzyme is accompanied by dissociation of the enzyme protein to subunits.View full abstractDownload PDF (1427K) -
Atsushi HARA, Tamotsu TAKETOMI1975 Volume 78 Issue 3 Pages 527-536
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSEquine renal glycosphingolipids were composed of galactocerebroside, glucocerebroside, ceramide dihexoside, ceramide trihexoside, sulfatide, globoside I, Forssman globoside, and hematoside. Free ceramide and sphingomyelin were also found in equine kidney. Their long chain bases consisted of sphingosine, dihydrosphingosine, C18-phytosphingosine, and C20-phytosphingosine, whereas the fatty acids were separated into two groups: nonhydroxy and hydroxy fatty acids. Ceramide monohexoside was separated into five spots by TLC on borax-impregnated plates. The major component of ceramide monohexoside was glucocerebroside which accounted for 46.6% of the total ceramide monohexoside and contained a ceramide consisting of phytosphingosines and hydroxy fatty acids. The long chain bases of hematoside and sulfatide contained dihydroxy and trihydroxy bases in nearly equal ratios. On the other hand, the other glycosphingolipids contained mainly dihydroxy bases, though with significant amounts of trihydroxy bases. Free ceramides were separated into four groups by silicic acid column chromatography and the major ceramides were of two kinds, consisting of dihydroxy bases and nonhydroxy fatty acids (49.9% of the total ceramide) and of trihydroxy bases and nonhydroxy fatty acids (38.5% of the total ceramide). The minor ceramides contained predominantly hydroxy fattyacids. Neither trihydroxy bases nor hydroxy fatty acids were detected in sphingomyelin.View full abstractDownload PDF (3012K) -
III. Purification and Properties of Streptomyces hachijoensis Phospholipase CYoshio OKAWA, Tsutomu YAMAGUCHI1975 Volume 78 Issue 3 Pages 537-545
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. Phospholipase C [EC 3. 1. 4. 3] found in the growth medium of Streptomyces hachijoensis was purified about sixty-fold by dialysis and column chromatography on Sephadex G-50.
2. The active fraction was separated by isoelectric focusing into two fractions, phospholipase C-I (pI 6.0) and phospholipase C-II (pI 5.6).
3. Both purified phospholipases C were homogeneous by immunodiffusion and were not differentiated as regards antigenicity.
4. Phospholipase C-I had maximal activity at pH 8.0 and the optimal temperature was 50°. Phospholipase C-I was stable at 50° for 30min and was stable at neutral PH.
5. The activity of phospholipase C-I was inhibited by high concentrations of various detergents such as Triton X-100, sodium cholate, SDS and was also inhibited by Ca2+, Ba2+, A13+, and EDTA, but was stimulated by Mg2+, and ethyl ether.
6. The Km value of phospholipase C-I was 0.9mM, using phosphatidylcholine as a substrate.
7. By the gel filtration procedure, the molecular weights of phospholipase C-I and-II were both determined to be 18, 000.
8. Phosphatidylcholine, phosphatidylinositol, cardiolipin, sphingomyelin, and lysophosphatidylcholine were hydrolyzed by phospholipase C-I, but phosphatidylethanolamine and phosphatidylserine were hydrolyzed with difficulty under the same conditions. Phospholipase C-I also hydrolyzed phosphatidic acid.View full abstractDownload PDF (1369K) -
Akio SASAKI1975 Volume 78 Issue 3 Pages 547-554
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSPhospholipids extracted with hot methanol from Mycobacterium tuberculosis, strain H37Rv, were fractionated with solvent mixtures and by partition chromatography on silica-gel columns. Of 12 components detected on a thin-layer chromatogram of the total phospholipid fraction, 6 components were purified. They were all phosphatidylinositol oligomannosides: two hexamannosides (H-2 and H-3), one tetramannoside (H-4), one trimannoside (H-5), and two dimannosides (H-6 and H-7). The molar ratios of fatty acid to phosphorus were 3 for H-2, H-4, H-5, and H-6, and 4 for H-3 and H-7. In each lipid, more than 80% of the total fatty acids were palmitic and tuberculostearic acids. Each of the six lipids had serological activity to various degrees.View full abstractDownload PDF (594K) -
Takashi SUZUKI, Yutaka MAEDA, Hiroshi SAKAI, Shigeru FUJIMOTO, Yuhei M ...1975 Volume 78 Issue 3 Pages 555-560
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMössbauer effect and electron paramagnetic resonance (EPR) were measured for yeast aconitase [EC 4. 2. 1. 3] purified from the cells of Candida lipolytica (ATCC 20114). Mössbauer spectra suggested that yeast aconitase mostly contained two high-spin Fe (III) ions in an antiferromagnetically coupled binuclear complex that resembled oxidized 2 Fe ferredoxins, together with a small amount of high-spin Fe (II). EPR spectra recorded no signal at 77°K, but showed a slightly asymmetric signal centered at g=2.0 at 4.2°K, presumably due to the small amount of Fe (II) Fe (III) pairs.View full abstractDownload PDF (426K) -
Yoshiyuki TAMURA, Yuhei MORITA1975 Volume 78 Issue 3 Pages 561-571
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThermal denaturation of Japanese-radish peroxidase [EC 1. 11. 1. 7] was investigated with respect to its spectrophotometric properties and effect on the enzymatic activity. Inactivation of the peroxidase occurred at temperatures higher than 60° and involved three processes, i.e., dissociation of protohemin from the holoperoxidase, a conformation change in the apoperoxidase, and the modification or degradation of protohemin. The splitting process of protohemin from holoperoxidase as followed by the change in the absorption spectrum at high temperatures coincided with the decrease in the activity, and it was found to be at least biphasic. The regeneration of peroxidase on cooling to room temperature was essentially reversible at neutral pH, while at pH 5 and pH 9 these processes were irreversible. The irreversibility at acidic pH was mainly due to an irreversible change in the conformation of the apoenzyme. The difference spectrum of heat-treated apoperoxidase exhibited a denaturation blueshift with negative maxima at 287 and 294 nm, and the total protein fluorescence quantum yield, qprotein, increased by 20% compared to that of the untreated apoenzyme. On the other hand, the irreversibility at alkaline pH was largely attributable to the modification of protohemin. Apoperoxidase was more resistant to heat denaturation but the modification or degradation of protohemin in heated enzyme was greater at alkaline pH than at acidic pH. The pyridine-ferrohemochrorne spectrum of peroxidase exhibited slight shifts of the maxima of the α-band to shorter wavelength on heat treatment, and the paper chromatogram showed the presence of a new derivative other than protohemin. The modified product is probably 2 (4)-vinyl-4 (2)-hydroxyethyldeuterohemin.View full abstractDownload PDF (761K) -
Yukio NISIMOTO, Fumio TAKEUCHI, Yukio SHIBATA1975 Volume 78 Issue 3 Pages 573-581
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSOuter membrane preparations of rat liver mitochondria were isolated, after the mitochondria had been prepared by mild digitonin treatment under isotonic conditions. -Kynurenine 3-hydroxylase [EC 1. 14. 13. 9] was solubilized on a large scale from outer membrane by mixing with 1% digitonin or 1% Triton X-100, followed by fractionation into a minor fraction I and a major fraction II by DEAE-cellulose column chromatography. The distribution of total -Kynurenine 3-hydroxylase was roughly 20 and 80% in fraction I and II, respectively. Fraction I consisted of crude enzyme loosely bound to anion exchanger. In the present investigation, fraction I was not used because of its low activity and rapid inactivation. In contrast, fraction II consisted of crude enzyme with high activity, excluded from DEAE-cellulose column chromatography in the presence of 1M KCl. In addition, fraction II was purified by Sephadex G-200 gel nitration and DEAE-Sephadex A-50 column chromatography with linear gradient elution, adding 1M KCl and 1% Triton X-100 to 0.05M Tris-acetate buffer, pH 8.1. After isoelectric focusing, the purified enzyme preparation was proved to be homogeneous, since the -kynurenine 3-hydroxylase fraction gave a single band on disc gel electrophoresis. The molecular weight of this enzyme was estimated to be approximately 200, 000 or more by SDS-polyacryl-amide gel electrophoresis and from the elution pattern on Sephadex G-200 gel filtration. A 16-fold increase of the enzyme activity was obtained compared with that of the mitochondrial outer membrane. The isoelectric point of the enzyme was determined to be pH 5.4 by Ampholine isoelectric focusing.View full abstractDownload PDF (1279K) -
Isolation and PropertiesToyoki KATO, Yuji TONOMURA1975 Volume 78 Issue 3 Pages 583-588
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe relaxing protein (TM-TN complex) was isolated from plasmodia of Physarum. SDS-gel electrophoresis revealed that the relaxing protein consists of tropomyosin subunits with a molecular weight of 35, 000, troponin subunits with molecular weights of 38, 000 (T) and 24, 000 (I) and several other components. No component corresponding to muscle troponin-C (MW=18, 000) was detected in the plasmodium relaxing protein. The relaxing protein combined with muscle F-actin, and inhibited the ATPase [EC 3. 6. 1. 3] activity and superprecipitation of reconstituted muscle actomyosin in the absence of Ca2+ ions. This inhibition was reversed by adding 1μM Ca2+ ions.View full abstractDownload PDF (1390K) -
Yoshiko NAKAE, Eisaku RYO, Seiki KURAMITSU, Kiyoshi IKEDA, Kozo HAMAGU ...1975 Volume 78 Issue 3 Pages 589-597
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe binding constants of N-acetylglucosamine (GlcNAc) and its methyl α-andβ-glycosides to hen and turkey egg-white lysozymes [EC 3. 2. 1. 17], in the latter of which Asp 101 is replaced by Gly, were determined at various pH values by measuring changes in the circular dichroic (CD) band at 295 nm. The binding of β-methyl-GlcNAc to turkey and hen lysozymes perturbed the pK value of Glu 35 from 6.0 to 6.5, the pK value of Asp 52 from 3.5 to 3.9, and the pK value of Asp 66 from 1.3 to 0.7. In addition, perturbation of the pK value of Asp 101 from 4.4 to 4.0 was observed in the binding of this saccharide to hen lysozyme. The binding of a-methyl-GlcNAc to hen and turkey lysozymes perturbed the pK value of Glu 35 to the alkaline side by about 0.5 pH unit, the pK value of Asp 66 to the acidic side by about 0.5 pH unit, and the pK value (4.4) of an ionizable group to the acidic side by about 0.6 pH unit. The last ionizable group was tentatively assigned to Asp 48. The pK value of Asp 52 was not perturbed by the binding of this saccharide. The pH dependence curves for the binding of GlcNAc to hen and turkey lysozymes were very similar and it was suggested that Asp 48, in addition to Asp 66, Asp 52, and Glu 35, is perturbed by the binding of GlcNAc.View full abstractDownload PDF (732K) -
III. Secondary Structure of 18 and 26S Yeast Ribosomal RNA's and Their Complex: Circular Dichroism and Infrared AnalysesKazuo YANAGI, Tatsuo KATSURA, Koujiro ISO1975 Volume 78 Issue 3 Pages 599-604
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSCircular dichroism (CD) and infrared (IR) spectroscopic analyses were performed of 26 and 18S yeast ribosomal RNA's (rRNA) and their specific complex, 30S RNA. The molecular ellipticity coefficients [θ] of 18, 26, and 30S rRNA's were 2.72, 2.63, and 2.65×104 degree•cm2/decimole at 264nm, respectively. The base-pairing contents of 18, 26, and 30S RNA's determined by infrared spectroscopy were 66% (30% AU, 36% GC), 66% (30% AU, 36% GC), and 70% (32% AU, 38%. GC), respectively. These results suggest that 18 and 26S rRNA have very similar secondary structures, and that 30S RNA may have a slightly higher base-pairing content than the estimated sum of those of 18 and 26S rRNA's. The biological significance of this phenomenon is discussed in this report.View full abstractDownload PDF (495K) -
Toshiharu HASE, Keishiro WADA, Hiroshi MATSUBARA1975 Volume 78 Issue 3 Pages 605-610
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAbout 20% of the total extractable ferredoxin from a blue-green alga, Aphanothece sacrum, was separated as a minor compnent on a DEAE-cellulose column during the preparation of the major component of the cells. It was always found in cells collected in three different seasons. The chemical properties of the minor component were different from those of the major one. The enzymatic activity and spectral properties were those of typical chloroplast-type ferredoxins. The significance of isozymes in ferredoxin is discussed.View full abstractDownload PDF (459K) -
Subtilisin-Benzeneboronic Acid SystemHiroshi NAKATANI, Yukiko UEHARA, Keitaro HIROMI1975 Volume 78 Issue 3 Pages 611-616
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe interaction of benzeneboronic acid (BBA), a possible transition state analog, with subtilisin BPN' [EC 3. 4. 21. 14] was studied by the temperature-jump method at various pH's, temperatures and in D2O as well as H2O. From analysis of the concentration dependence of the relaxation times, it was suggested that the subtilisin-BBA interactions consist of at least two elementary steps, a fast bimolecular association followed by a slow unimolecular process. Similar concentration dependence was observed at pH 6.1-6.7 at 25°. However, in D20 the reciprocal relaxation times generally decreased compared to those in H2O and became concentrationindependent below pD 6.5. The relaxation times were influenced considerably by the temperature. From these results, the slow unimolecular process was assigned to the trigonal-tetrahedral interconversion of BBA at the active site of the enzyme.View full abstractDownload PDF (1085K) -
III. Action on Ester, Amide, and Anilide Substrates and the Effects of Some Environmental FactorsYasuo BAI, Rikimaru HAYASHI, Tadao HATA1975 Volume 78 Issue 3 Pages 617-626
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSKinetic parameters of carboxypeptidase Y are given for the hydrolyses of ester, amide, and anilide substrates. The kcat/Km values were compatible with those of chymotrypsin [EC 3. 4. 21. 1] with a few exceptions. One ionizable group with a pK of around 5.8 was suggested to be involved in the free enzyme in hydrolyzing all the substrates, including peptide substrates. In addition, hydroxylaminolysis and the kinetic isotope effects of deuterium oxide indicated, with some reservations, a reaction mechanism which proceeds via the formation of an acyl intermediate.View full abstractDownload PDF (765K) -
Shoshi OTA, Hiroko UMI, Eiko MUTA, Yoshiko OKAMOTO1975 Volume 78 Issue 3 Pages 627-635
Published: September 25, 1975
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (651K)
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