All issues
Volume 75 (1974)
- Issue 6 Pages 1201-
- Issue 5 Pages 951-
- Issue 4 Pages 679-
- Issue 3 Pages 441-
- Issue 2 Pages 215-
- Issue 1 Pages 1-
Volume 75, Issue 3
Displaying 1-28 of 28 articles from this issue
- |<
- <
- 1
- >
- >|
-
Toshio TAKAGI, Tadashi IZUTSU1974 Volume 75 Issue 3 Pages 441-446
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe contribution of disulfide groups to the observed circular dichroic spectrum of bovine pancreatic ribonuclease [EC 2. 7. 7. 16] in 6M guanidine hydrochloride, pH 3.0, in the near ultraviolet region was estimated by measuring circular dichroic spectra before and after reduction of the groups with dithioerythritol and taking the difference. The groups were found to have a negative circular dichroic band at 262nm with a residue molar ellipticity of -1, 900 deg•cm2•decimole-1 at 5°C. The optical activity was shown to be similar but not identical to the circular dichroic spectrum of N, N'-diacetyl-L-cystine bismethylamide, which is thought to be a good model compound for L-cystine residue.View full abstractDownload PDF (513K) -
Tatsuhisa YAMASHITA, Yaeko SOMA, Shizuko KOBAYASHI, Takamitsu SEKINE1974 Volume 75 Issue 3 Pages 447-453
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe primary structure of peptides containing the specific sulfhydryl groups, named S1 and S2, in the active site of myosin A ATPase [EC 3. 6. 1. 3], was re-investigated using N-(4-dimethylamino-3, 5-dinitrophenyl) maleimide (DDPM) as a tracer. The amino acid sequence Cys. Asn. Gly was assigned to the “pronase”-digested peptide involving S2 responsible for the activity of Ca2+-ATPase elevated by blocking S1. In addition, the amino acid composition of a chymotryptic S1-containing peptide was determined with special reference to the heterogeneity of myosin subunits. Some chemical properties of S-DDPS-cysteine, a reference compound for the analysis of S-DDPS-peptide, are also described.View full abstractDownload PDF (521K) -
Hiroshi IKENAGA, Kenji TAKAHASHI1974 Volume 75 Issue 3 Pages 455-462
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSUpon treatment of bovine carboxypeptidase A [EC 3. 4. 2. 1] with phenylglyoxal, an arginine-specific reagent, at pH 8.0 and 25°C, the peptidase activity was lost very rapidly whereas the esterase activity was lost more slowly. The inhibitor, β-phenylpropionic acid, showed some protection against loss of the esterase activity but not against loss of the peptidase activity. These changes in the activites following reaction with phenylglyoxal occurred with concomitant modification of 2 to 3 arginine residues in the enzyme. A preliminary attempt has been made to locate the modified arginine residues by analyzing the fragments obtained by cleavage with cyanogen bromide of phenylglyoxal-modified carboxypeptidase A.View full abstractDownload PDF (552K) -
Ryoko KURIYAMA, Hikoichi SAKAI1974 Volume 75 Issue 3 Pages 463-471
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe reconstitution of tubulin to microtubules in vitro has been demonstrated by the measurement of viscosity changes in addition to electron microscopic observations. The viscosity increase in the reassembly buffer was accompanied by a proportional increase in the length of reconstituted microtubules. The half-life time of decay in polymerizability of tubulin was determined at various protein concentrations. The effects of low temperature, colchicine, nucleotides, divalent cations, ionic strength, and the requirement for “nuclei” materials have been investigated. The viscosity dropped sharply to the original level when the temperature was lowered, and 10-4M colchicine also induced depolymerization. In a nucleotide-free reassembly buffer, no polymerization could be induced, whereas the viscosity immediately increased on addition of GTP, ATP, ITP, UTP, CTP, TTP, or ADP. Ca2+ ions instantaneously caused degradation of reconsituted microtubules, but the effect was completely reversed by adding excess ethyleneglycol-bis (2-aminoethylether)-N, N, N', N'-tetra acetic acid (EGTA). On the other hand, Mg2+ ions were an essential requirement for tubulin polymerization. As in actin polymerization, an ionic strength of 0.1 (KC1) favored the reassembly of microtubules. A requirement for “nuclei” for reassembly was also demonstrated by viscosity measurements.View full abstractDownload PDF (1399K) -
Naoyuki TANIGUCHI1974 Volume 75 Issue 3 Pages 473-480
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSγ-Glutamyl transpeptidase [EC 2. 3. 2. 2] was purified from azo dye-induced hepatoma of rats and its molecular and catalytic properties were studied. The purified enzyme appeared to be homogeneous as judged by ultracentrifugation and disc electrophoresis. The molecular weight was determined to be 113, 000. The enzyme was a glycoprotein containing approximately 36% carbohydrate. The partial specific volume was 0.710 and the sedimentation coefficient was 5.60S. The molecular activity of the enzyme was 20, 500 at 37°C. The purified enzyme was very similar to hog and beef kidney enzymes in catalytic properties.View full abstractDownload PDF (1366K) -
Michiyo KAMBE, Yasuo IMAE, Kiyoshi KURAHASHI1974 Volume 75 Issue 3 Pages 481-493
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMutants which could not produce gramicidin S were isolated from Bacillus brevis ATCC 9999 by UV irradiation or N-methyl-N'-nitro-N-nitrosoguanidine treatment. They were classified into three groups by means of complementation tests in vitro using purified complementary fractions of gramicidin S synthetase, Fraction I and Fraction II [phenylalanine racemase, EC 5. 1. 1. 11]. The former activates L-proline, L-valine, L-ornithine, and L-leucine and the latter L- and D-phenylalanine. The first group lacked Fraction II activity, the second both Fraction I and Fraction II activities, and the third Fraction I activity.
ATP-32PPi exchange activities depending on the constituent amino acids of gramicidin S were determined after fractionation of mutant extracts by sucrose density gradient centrifugation. It was found that the third group of mutants was possibly classified into several subgroups. One mutant hh had activating activities for three amino acids (L-proline, L-valine, and L-ornithine), but lacked L-leucine activating activity intrinsic to Fraction I. The other mutant n-7 lacked activating activities for all four amino acids which should be present in the region of Fraction I, although L-proline activating activity was detected in the region of Fraction II.
D-Phenylalanyl-L-proline diketopiperazine synthesizing activity was not present in the mutant hh extract, but was detected in the mutant n-7 extract. This result indicates that some modifications of Fraction I result in failure to associate with racemase in the case of mutant hh, despite the fact that the L-proline activating subunit of Fraction I alone could associate with racemase to make an active complex for diketopiperazine synthesis in the case of mutant n-7.View full abstractDownload PDF (2534K) -
Their Action on Glycolipids and Allied OligosaccharidesYousuke SEYAMA, Tamio YAMAKAWA1974 Volume 75 Issue 3 Pages 495-507
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSβ-N-Acetylhexosaminidase [EC 3. 2. 1. 52] extracted from equine kidney had three components, acidic A, basic B, and a third one A'. These three components were separated by a combination of DEAE- and CM-cellulose column chromatography. Isoelectric points were: A, 6.07; A', 6.25; B, 8.20. Component A was heat labile. Component B was relatively stable against heat treatment but lost activity rapidly above 55°C. Component A' was very heat stable, and retained 75% of its activity after 30min at 60°C. The molecular weights of A, A', and B were 125, 000, 250, 000, and 125, 000 daltons, respectively. The Michaelis constants against phenyl β-N-acetylgalactosaminide were A: 0.147mM, A': 0.102mM, and B: 0.043mM, and those against p-nitrophenyl β-N-acetylgalactosaminide was A: 0.571mM, A': 0.246mM, and B: 0.086mM. Oligosaccharide obtained from ganglioside GM2 was hydrolyzed only by A and A', not by B, and those from asialo GM2 and Globoside I were hydrolyzed by all three components. Component A preparation free from sialidase [EC 3. 2. 1. 18] was not converted to B by sialidase from Cl. perfringens.View full abstractDownload PDF (1958K) -
Masanori NISHIGAKI, Takashi MURAMATSU, Akira KOBATA, Ken-ichi MAEYAMA1974 Volume 75 Issue 3 Pages 509-517
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe α-L-fucosidases [EC 3. 2. 1. 51] purified from Turbo cornutus and Charonia lampas hydrolyzed all the fucosidic linkages found in milk oligosaccharides. These linkages include Fucα1→2Gal, Fucαl→3GlcNAc, Fucαl→4GlcNAc, and Fucα1→3sorbitol. The α-L-fucosidase from T. cornutus hydrolyzed the fucosidic linkages in lacto-N-fuco-pentaitols in the following order of velocity: Fucαl→4GlcNAc>Fucαl→2Gal>Fucαl→3GlcNAc; The enzyme from C. lampas gave the following order: Fucαl→2Gal>Fucαl→4GlcNAc>Fucαl→3GlcNAc. The α-L-fucosidases from T. cornutus and C. lampas also released fucose from mouse myeloma IgG glycopeptide and porcine submaxillary mucin. Thus, these α-L-fucosidases are a new type of α-L-fucosidase acting on a wide variety of fucosyl linkages in both low and high molecular weight substrates.View full abstractDownload PDF (687K) -
XIII. Sulfite Reductase from Desulfovibrio vulgaris-Mechanism of Trithionate, Thiosulfate, and Sulfide Formation and Enzymatic PropertiesKunihiko KOBAYASHI, Yasuhide SEKI, Makoto ISHIMOTO1974 Volume 75 Issue 3 Pages 519-529
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe reaction of sulfite reductase [EC 1. 8. 99. 1] from Desulfovibrio vulgaris was investigated using a purified enzyme preparation in a system coupled with methyl viologen and hydrogenase [EC 1. 12. 2. 1].
Trithionate, thiosulfate, and sulfide were detected even in the early phase of sulfite reduction and the amount of each compound did not decrease during the reaction or after hydrogen uptake ceased. The specific radioactivity of sulfide formed from 35S-labelled sulfite was scarcely reduced on adding cold trithionate and only slightly on adding cold thiosulfate. These results, in addition to the fact that trithionate and thiosulfate are not reduced by the enzyme, indicate that these three compounds are produced by sulfite reductase.
At high concentrations of sulfite and low concentrations of methyl viologen or hydrogenase, trithionate was the dominant product. Under the opposite conditions, the formation of relatively large amounts of sulfide or thiosulfate was observed. On the basis of these findings, a mechanism was proposed for the reaction, including labile intermediates, presumably sulfoxylate and elemental sulfur, which accept electrons from reduced methyl viologen to form sulfur and sulfide or react with sulfite to produce trithionate and thiosulfate, respectively.
Some enzymatic properties were examined. Km was 3.6×10-3M for sulfite. The optimum pH was 5.5 to 6.0. The enzyme was partially inhibited by arsenite at concentrations of lO-2 to 10-4M. It could reduce hydroxylamine, nitrite, and trimethylamine N-oxide, but not nitrate, chlorate, cyanide, azide, adenosine N-oxide, or taurine. Disc electrophoresis and enzyme staining using oxidation of reduced methyl viologen with acceptors in polyacrylamide gel revealed that desulfoviridin had reducing activities not only for sulfite but also for hydroxylamine and nitrite.View full abstractDownload PDF (1572K) -
I. Effects of Culture Conditions on the Multiplicity of CellulaseTakafumi YOSHIKAWA, Hiroshi SUZUKI, Kazutosi NISIZAWA1974 Volume 75 Issue 3 Pages 531-540
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIn the culture medium of a cellulolytic bacterium, Pseudomonas fluorescens var. cellulosa, several extracellular cellulase [EC 3. 2. 1. 4] components of different molecular weights were found, and the number of components increased in parallel with the culture period. Of these cellulase components, at least five (peaks I, II, III, IV, and V) were electrophoretically separated further into two components, A and B, in varying proportions. Peak I and peak V were composed almost exclusively of B and A, respectively. The ratio of total A to total B increased during bacterial growth. Moreover, peak I which had the largest molecular weight among the detectable extracellular cellulases was found to decrease in amount during culture, and almost disappeared at the later stages of culture. On the other hand, only peak I was found in the intrawall fraction during earlier stages of culture in which active secretion of extracellular cellulases was taking place. These facts strongly suggest that the multiple cellulase components in the culture medium are secondarily formed from peak I outside the cell.View full abstractDownload PDF (664K) -
Hiroyuki SUMI, Setsuro FUJII1974 Volume 75 Issue 3 Pages 541-551
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSSeveral inhibitors were separated from human serum by gel filtration on Sephadex G-200, and a new inhibitor was further purified by successive column chromatography on DEAE-cellulose, hydroxylapatite and Sepharose-4B. By these procedures, 8.4mg of purified kallikrein inhibitor was obtained from 40ml of human serum. The purified material was homogeneous, as judged by cellulose acetate electrophoresis, discelectro-phoresis, and ultracentrifugation. It had an s20, w value of 4.2 and an apparent molecular weight of 53, 000, as measured by gel filtration on Sephadex G-200. The purified inhibitor was heat-labile and was unstable below pH 5.5, a pH value at which esterolysis of Nα-tosyl-L-arginine methyl ester and kinin formation by plasma kallikrein [EC 3. 4. 4. 21] are progressively inhibited. It also inhibited plasniin [EC 3. 4. 4. 14] and thrombin [EC 3. 4. 4. 13]. One mg of kallikrein inhibitor neutralized 5.3 TAME-esterolytic units of plasma kallikrein activated with acetone, 1.5 TAME-esterolytic units of plasmin activated with streptokinase and 5.6 TAME-esterolytic units of thrombin. On the other hand, it had only weak affinities for trypsin [EC 3. 4. 4. 4] and chymotrypsin [EC 3. 4. 4. 5]. This kallikrein inhibitor appeared to be a new inhibitor, distinct from the serum trypsin and Cl-esterase inhibitors described previously.View full abstractDownload PDF (1825K) -
Yozo HIBINO, Yoshiaki NOSOH, Tatsuya SAMEJIMA1974 Volume 75 Issue 3 Pages 553-561
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMeasurements of the optical rotatory dispersion and circular dichroism of NADP-dependent isocitrate dehydrogenase [EC 1. 1. 1. 42] from B. stearothermophilus revealed the presence of about 30% α-helical structure in the molecule. In the presence of substrate, the optical activity properties differed from those of the native enzyme alone, suggesting a slight decrease of α-helical conformation in the enzyme. Under denaturing conditions (thermal or 8M urea treatment), the substrate protected the enzyme molecule from denaturation. These results suggested that the interaction of substrate with the enzyme enhanced the stability of the enzyme.View full abstractDownload PDF (1176K) -
Masatoshi KATO, Keitaro HIROMI, Yuhei MORITA1974 Volume 75 Issue 3 Pages 563-576
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. β-Amylase [α-1, 4-glucan maltohydrolase, EC 3. 2. 1. 2] from wheat bran was purified to a single protein component as determined by ultracentrifugal analysis and polyacrylamide gel disc electrophoresis. The enzyme preparation was proved to be free from α-amylase [EC 3. 2. 1. 1] contamination, as judged from the relationship between the blue value and the reducing value.
2. The Michaelis constant Km and the molecular activity k0 were determined at 25°C and pH 5.20 for the β-amylase-catalyzed hydrolyses of G3, G7, and G760, where Gn denotes a linear substrate with degree of polymerization n. The values of k0/Km were determined for a series of linear substrates, G3-G7, G12.5 and G760 from measurements of the initial rate for each substrate at a substrate concentration sufficiently lower than its Km value.
3. From the dependence of k0/Km on n, the number of subsites of this enzyme was estimated to be five. According to the subsite theory (30), the values of k0/Km and Km were used to evaluate the subsite affinity Ai of each subsite, where i is the subsite number counting from the terminal subsite at which the nonreducing end glucose residue of a substrate is to be situated. The values of (A1+A2), A3, A4, and A5, were evaluated, and the lower limit of A1 and the upper limit of A2 were also estimated. The large positive values of A1 and A4, and the negative values of A2 and A3 are consistent with the experimental data that maltotetraose is the smallest good substrate and that maltose and phenyl α-maltoside are not hydrolyzed to any detectable extent.View full abstractDownload PDF (1490K) -
Effect of Growth Conditions on Alcohol Dehydrogenase Synthesis in Leuconostoc mesenteroidesSusumu ITO, Honoo HASHIBA, Yoshitomo EGUCHI1974 Volume 75 Issue 3 Pages 577-581
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe effect of growth conditions on the levels of both NAD- and NADP-linked alcohol dehydrogenases [EC 1. 1. 1. 1 and 1. 1. 1. 2] in extracts of Leuconostoc mesenteroides IFO 3426 was examined. When glucose was used as a carbon source, the levels of both enzyme were repressed by aerobiosis. Induction of these enzyme activities was observed when aerobic cultures were shifted to anaerobiosis. Chloramphenicol arrested this increase. It was also found that the enzyme levels produced in an anaerobic environment were variable and depended upon the carbon source added. Anaerobic growth on glucose resulted in a maximal level, whereas growth anaerobically on a non-glucose substrate such as 2-ketogluconate, xylose, or fructose, resulted in approximately four-fold to ten-fold decreases in this maximum.
From these results, it was suggested that the synthesis of alcohol dehydrogenases in this organism was not regulated by molecular oxygen as such but depended upon the disposal of substrate hydrogen.View full abstractDownload PDF (362K) -
V. An Enzyme-FMN Intermediate Complex in the Bioluminescent ReactionKenzaburo YOSHIDA, Masami TAKAHASHI, Takao NAKAMURA1974 Volume 75 Issue 3 Pages 583-589
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA luciferase-FMNH2 complex was mixed with O2 and the changes in the absorption and fluorescence spectra of the reaction mixture were followed by the stopped-flow method. Rapid formation of an enzyme-FMN intermediate complex, with a broad absorption band at 430-470nm, was observed. The fluorescence emission maximum of the intermediate coincided with that of free FMN. The decay rate of the intermediate (0.25 sec-1 at 20°C) was in agreement with that of an obligatory intermediate of the luminescent reaction, as determined by the method of aldehyde-initiated luminescence. After forming a complex with aldehyde, the decay rate of the intermediate was dependent on the chain length of the aldehyde. The intermediate was more effectively protected by aldehydes of longer chain length against back-reduction by excess dithionite.View full abstractDownload PDF (1269K) -
III. Purification and Properties of a Mercuric Ion Reducing Enzyme from Escherichia coli Bearing R FactorKazuo IZAKI, Yüko TASHIRO, Tsukasa FUNABA1974 Volume 75 Issue 3 Pages 591-599
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA mercuric ion reducing enzyme from E. coli W 2252 bearing R factor was purified approximately 100-fold by ammonium sulfate fractionation, DEAE-cellulose chromatography and Sephadex G-200 gel filtration. The purified enzyme had a characteristic absorption spectrum, similar to those of flavin compounds. FAD was detected as a component of the purified enzyme as a result of analysis using thin-layer chromatography and D-amino acid oxidase [EC 1. 4. 3. 3] apoenzyme. FAD stimulated the enzymatic oxidation of NADPH by the acid-precipitated enzyme depending on mercuric ions, while FMN did not have such a stimulating effect. Rapid oxidation of NADPH was observed in the presence of both the purified enzyme and HgCl2. Combinations of the purified enzyme and organic mercurials such as mercurochrome or phenylmercuric acetate, however, did not oxidize NADPH. Km for HgCl2 was 0.05mM. NADPH and, to a lesser extent, NADH seemed to act as electron donors for the enzymatic reduction of HgCl2. Various SH compounds such as 2-mercaptoethanol, cysteine, dithiothreitol, and glutathione (reduced form) were effective and essential for the enzyme activity.View full abstractDownload PDF (681K) -
Takeo MATSUZAWA1974 Volume 75 Issue 3 Pages 601-609
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. The inhibition of rat liver ornithine-δ-aminotransferase [EC 2. 6. 1. 13] by branchedchain amino acids (L-valine>L-isoleucine>L-leucine) was highly specific among various amino acids and metabolites tested. In chemical characterization of the inhibitor structure, the carboxyl group was essential, but the α-amino group was only complementary. The inhibitory action was largely dependent on the branched structure of the hydrophobic residue. It was shown that only L-valine exists in a great enough concentration in mitochondria to inhibit the forward reaction.
2. In the overall reaction, inhibition by L-valine was absolutely competitive with respect to ornithine, noncompetitive with respect to glutamate and pyrroline-5-carboxylate, and uncompetitive with respect to 2-oxoglutarate. The kinetic results showed that L-valine interacts only with the phosphopyridoxal enzyme, resulting in inhibition of the forward reaction, but L-valine was a noncompetitive inhibitor in the reverse reaction.
In the forward reaction:
Km for L-ornithine, 1.0mM; Ki for L-valine, 2.0mM;
Km for 2-oxoglutarate, 0.7mM.
In the reverse reaction;
Km for L-glutamate, 25mM; Ki for L-valine, 20mM;
Km for DL-pyrroline-5-carboxylate, 1.4mM.
The Ki value for L-valine in the forward reaction was 10 times smaller than that in the reverse reaction. Thus, the forward reaction is readily inhibited in the presence of actual intramitochondrial concentrations of L-valine. The exchange reactions (α and δ-amino exchange reacions, respectively) were also affected by L-valine, as well as the overall reaction.View full abstractDownload PDF (634K) -
Kazunori SHIMADA, Takeharu NISHIMOTO, Yasuyuki TAKAGI1974 Volume 75 Issue 3 Pages 611-617
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA simple and sensitive method has been devised which allows the determination of DNA strand breaks produced in vitro. It is based on the loss of renaturability (zippering-up) of DNA with strand-breaks in a high ionic strength solution and on the ability of nitrocellulose filters to specifically retain denatured DNA.
This method was found to be suitable for the sensitive detection of double-stranded breaks in native DNA produced by DNase II [EC 3. 1. 4. 6]. It was also applied on a semi-quantitative basis for the detection of single-stranded breaks produced by both DNase I [EC 3. 1. 4. 5] on native DNA and by Micrococcus lysodeikticus extracts on UV-irradiated DNA. The results of this assay were in agreement with assays of strand breaks using alkaline sucrose gradients.View full abstractDownload PDF (529K) -
Michihiro SUGANO1974 Volume 75 Issue 3 Pages 619-625
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe rate of utilization of triglyceride fatty acids in cholesterol esterification in rat plasma was studied in vivo using glyceryl tri[l-14C]palmitate, oleate, and linoleate under conditions where the initial rate of utilization could be measured.
Labelled triglycerides coated on Celite 545 were shaken with rat serum at 0-2°C for 22-24hr and the centrifugal supernatant was injected intravenously into rats. Blood was collected at timed intervals from 15 to 240min after the dose. These triglyceride fatty acids were apparently utilized for the esterification in vivo, the extent of which was considerably greater with unsaturated triglycerides than saturated. The major route for the utilization of triglyceride fatty acids as acyl donors for esterification in vivo appeared to proceed via intermolecular transfer of the fatty acids from triglyceride to phospholipids, possibly to the 2-position of lecithin. The possible significance of other lipid component(s) as a donor of palmitic acid for the reaction was suggested.View full abstractDownload PDF (449K) -
I. Purification and Some Physical PropertiesKihachiro UEHARA, Sadaki FUJIMOTO, Takashi TANIGUCHI1974 Volume 75 Issue 3 Pages 627-638
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe violet-colored acid phosphatase [EC 3. 1. 3. 2] was purified from sweet potato tubers. The most purified preparation was found to be homogeneous by electrophoresis and ultracentrifugation. Concentrated solutions of the highly purified enzyme had an intense violet color with a broad absorption between 410mμ and 700mμ.The peak was at around 555mμ. The enzyme activity was lost following a variety of treatments in parallel with the disappearance of the absorbance in the visible region. Manganese, magnesium, boron, and silicon were detected in the purified enzyme preparation by emission spectroscopy. The molecular weight was estimated to be approximately 105, 000 and 110, 000 by sedimentation equilibrium and gel filtration on Sephadex G-200, respectively. Polyacrylamide gel disc electrophoresis in the presence of sodium dodecyl sulfate suggested that the enzyme dissociated into subunits with a molecular weight of approximately 55, 000. An isoelectric point determined from the electrofocusing experiments was near 5.0.View full abstractDownload PDF (2292K) -
II. Enzymatic Properties and Amino Acid CompositionKihachiro UEHARA, Sadaki FUJIMOTO, Takashi TANIGUCHI, Kunihide NAKAI1974 Volume 75 Issue 3 Pages 639-649
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe properties of the violet-colored acid phosphatase [EC 3. 1. 3. 2] isolated from sweet potato tubers have been investigated in more detail. The enzyme catalyzed the hydrolysis of a wide variety of phospho'rylated compounds including phosphomonoesters, nucleotide mono-, di-, and triphosphates, and inorganic pyrophosphate. No activity was detected for NAD+ and diphenyl phosphate. The optimal pH of hydrolysis was found to be approximately 5.8. The Km value determined with p-nitrophenyl phosphate, the most active substrate so far examined, was 6.8×lO-5M. Orthophosphate, arsenate, and molybdate inhibited the enzyme activity competitively with p-nitrophenyl phosphate, whereas fluoride acted as an uncompetitive inhibitor. The enzyme was also inactivated by prior incubation with chelating agents such as o-phenanthroline and α, α'-dipyridyl. Restoration of the activity after inactivation was observed following the addition of Zn2+, Co2+, or Mn2+. Preincubation of the enzyme with Hg2+ caused rapid activation to a level as high as about 3 times the original activity. The substrate specificity and the stability of the Hg2+-treated enzyme were found to be significantly different from those of the native enzyme. This enzyme, however, had essentially the same pH optimum as the native enzyme. The amino acid composition of the violet-colored acid phosphatase was also determined.View full abstractDownload PDF (764K) -
Effect of TemperatureToshihiko HAYASHI, Yutaka NAGAI1974 Volume 75 Issue 3 Pages 651-654
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (248K) -
Kazuyasu NAKAYA, Kazuko ARIGA, Fumio OBATA, Yasuharu NAKAMURA1974 Volume 75 Issue 3 Pages 655-657
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (240K) -
III. Effects of α-Hydroxyl and α-Methoxyl Substituents of the Substrate-2-acetamide Group on Enzymatic HydrolysisKazuhiko YAMAMOTO1974 Volume 75 Issue 3 Pages 659-661
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (167K) -
Kei TSUZURAHARA, Takaharu HIRAMATSU, Shigeyuki TAKEYAMA1974 Volume 75 Issue 3 Pages 663-665
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (189K) -
Shojiro YAMAZAKI, Ayako MATSUSHIMA, Akio TSUCHII, Yuji INADA1974 Volume 75 Issue 3 Pages 667-669
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (213K) -
Hideo SUGITA, Tomoh MASAKI, Setsuro EBASHI1974 Volume 75 Issue 3 Pages 671-673
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (820K) -
Wataru SAKAMOTO, Osamu NISHIKAZE, Eiichi SAKAKIBARA1974 Volume 75 Issue 3 Pages 675-677
Published: March 25, 1974
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (194K)
- |<
- <
- 1
- >
- >|