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VIII. Circular Dichroism Study in the Ultraviolet Region
Hirobumi OHAMA, Nobuhiko SUGIURA, Kunio YAGI
1974 Volume 76 Issue 1 Pages
1-6
Published: July 25, 1974
Released on J-STAGE: November 18, 2008
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1. The circular dichroism (CD) spectra of the apo- and holoenzyme of D-amino acid oxidase [D-amino acid: O
2 oxidoreductase (deaminating), EC 1. 4. 3. 3] in the farultraviolet region were analysed by a curve-fitting technique using the data for poly-L-lysine. The results indicate that the apoenzyme contains 17% α-helix, 32% β-structure, and 51% unordered conformation, and the holoenzyme 16% α-helix, 38% β-structure, and 46% unordered conformation.
2. The CD spectrum of the holoenzyme in the near-ultraviolet region exhibits a negative band around 297nm, a sharp positive band at 289nm and a broad positive band ranging from 255 to 275nm, differing from that of the apoenzyme. The sharp positive band at 289nm seems to be ascribable to the contribution of tryptophanyl residues, suggesting that conformational change occurs in the apoenzyme upon complex formation with the coenzyme.
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Masatake OHNISHI, Toshihiko SUGANUMA, Keitaro HIROMI
1974 Volume 76 Issue 1 Pages
7-13
Published: July 25, 1974
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A tyrosine residue of liquefying α-amylase [EC 3. 2. 1. 1] from
B. subtilis was acetylated with acetic anhydride and the effect of the modification on the rate of enzyme reaction was studied with a series of maltooligosaccharides. It was found that the acetylation of a tyrosine residue leads to partial loss of enzyme activity and that the effect does not depend appreciably on the degree of polymerization (
n) of the linear substrates in the range
n=3_??_7 and 760. The results are consistent with the supposition that the modified tyrosine residue is located at a subsite near the catalytic site and is involved in the productive binding of all the substrates studied.
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Akira MISAKI, Nobuyo SETO, Ichiro AZUMA
1974 Volume 76 Issue 1 Pages
15-27
Published: July 25, 1974
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D-Arabino-D-galactan, the main antigenic polysaccharide of
Mycobacterium species, was isolated from the cell walls of
M. tuberculosis strain H
37R
v, H
37R
a and Aoyama B,
M. bovis BCG,
M. phlei and
M. smegmatis, and also atypical
Mycobacterium P1. All arabinogalactan preparations had similar chemical properties ([α]D+23.5-28°; ratio of D-arabinose to D-galactose, 5:2), and were immunologically identical. They have ramified structures, with repeating units of 11-16 sugar residues, consisting of α-(1→5)- and (1→2) (minor)-D-arabinofuranosidic linkages, and, β-(1→4)-D-galactopyranosidic (or (1→5)-furanosidic) linkages; the side chains are terminated with arabinofuranose residues and are attached to the main chains at C-3 of arabinose and probably at C-6 of galactose residues, respectively.
The action of bacterial M-2 enzyme on the arabinogalactan of
M. phlei resulted in the release of a series of D-arabino-oligosaccharides, which included α-(1→5)-linked arabinobiose, -triose, and -tetraose, leaving a degraded polysaccharide (ratio of arabinose to galactose, 2:5.4) which may represent a back-bone chain. The inhibitory activities of these oligosaccharides in the precipitin reaction between the arabinogalactan and the anti-cell-wall sera indicate that the arabinofuranosyl side chains are responsible for the serological activity of the cell-wall polysaccharides. The arabinogalactan preparations reacted not only with antisera against mycobacterial cell walls but also with those against
Corynebacterium diphtheriae and
Nocardia asteroides, suggesting that the arabinogalactan is a common antigen of these bacterial groups.
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Sueo MATSUMURA, Yasutomi NISHIZUKA
1974 Volume 76 Issue 1 Pages
29-38
Published: July 25, 1974
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Endogenous rat liver substrate proteins for adenosine 3', 5'-monophosphate (cyclic AMP
*)-dependent protein kinase [EC 2. 7. 1. 37] were analyzed by means of polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The substrate proteins were assayed in terms of their ability to accept the terminal phosphate of ATP in the presence of protein kinase obtained from the soluble fraction of the same tissue. A number of substrate proteins were found in all subcellular fractions, including cytosol, microsomes, mitochondria, and nuclei. Plasma membranes also contained phosphate acceptors. Among nuclear proteins, not only histone but also nonhistone proteins were active as substrates. The existence of numerous substrate proteins within the cell is compatible with the view that cyclic AMP-dependent protein kinase may play a role in various processes controlled by cyclic AMP in this tissue.
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Kenji SORIMACHI, Nobuo UI
1974 Volume 76 Issue 1 Pages
39-45
Published: July 25, 1974
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An improved chromatographic procedure for the quantitative determination of iodo amino acids in thyroglobulin is described. In this method, thyroglobulin hydrolyzed by the combined use of Pronase and aminopeptidase M is applied to a column of AG 50W-X4 (30-35μ) equilibrated with 0.04M ammonium acetate buffer, pH 4.7, containing 30% (v/v) ethanol. By the application of a simple gradient of increasing pH to 1 N NH
4OH in the presence of 30% ethanol, five components,
i.e., I
-, monoiodotyrosine, diiodotyrosine, thyroxine, and 3, 5, 3'-triiodothyronine are separately eluted in that order, and they are determined quantitatively by automatic analysis of the effluent based on the ceric-arsenite reaction. Reproducible and accurate data are thus provided within 3 hr; the amount of undigested material is almost nil and the extent of deiodination of iodoamino acids occurring during the operation can be minimized.
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Issei MABUCHI
1974 Volume 76 Issue 1 Pages
47-55
Published: July 25, 1974
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A myosin-like protein, “ovomyosin, ” was extracted from the isolated cortical layer of cleaving starfish eggs. It was purified by ultracentrifugation, ammonium sulfate fractionation, sucrose density gradient centrifugation and precipitation at an ionic strength of 0.2. This enzyme had Ca
2+-activated ATPase [EC 3. 6. 1. 3] activity and a sedimentation coefficient of 6-7S. The main component of purified ovomyosin fraction showed the same mobility as the heavy chain of rabbit skeletal muscle myosin on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Ovomyosin could form thick filaments in 0.2M KCl. However, rabbit F-actin failed to activate the Mg
2+-dependent ATPase activity of ovomyosin. The content of ovomyosin in the cortical layer in relation to that of ovoactin and its role in cytokinesis of the starfish egg are discussed.
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Nobuyuki SUETSUGU, Shunsaku KOYAMA, Ken'ichi TAKEO, Takashi KUGE
1974 Volume 76 Issue 1 Pages
57-63
Published: July 25, 1974
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1) Hydrolyses of α-, β-, and γ-cyclodextrins catalyzed by Taka-amylase A
*3 [EC 3. 2. 1. 1] were studied at pH 5.3 and 25°C.
2) The rate parameters, Michealis constant
Km and molecular activity κ
0 for the cleavage of the cyclodextrin ring, were determined for the three cyclodextrins by using glucoamylase
*4 [EC 3. 2. 1. 3] in the analytical procedure to discriminate ring cleavage from the subsequent hydrolysis of chain product. It was found that the κ
0 value increased markedly in the order α-, β-, and γ-cyclodextrins, but the
Km values did not differ to any great extent among the three cyclodextrins.
3) By using glucoamylase, it was shown that the multiple attack mechanism was operative in the hydrolysis of cyclodextrins by this enzyme, and the degree of multiple attack was estimated to be 1.5±0.1, irrespective of the kind of cyclodextrin.
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Mikio ARISAWA, Hiromi B. MARUYAMA
1974 Volume 76 Issue 1 Pages
65-72
Published: July 25, 1974
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During growth under phosphate-deficient conditions,
Escherichia coli K12: W3110 cells acquired an apparent resistance to hypotonic lysis accompanied by a markedly reduced release of perienzymes into the medium when subjected to spheroplast formation or “osmotic shock” treatment. In parallel with these changes in the cell membrane, a reduction in the agglutinability of phosphate-deficient spheroplasts was found when they were incubated with concanavalin A after trypsin treatment. Based on these results, cell surface changes caused by phosphate deficiency were discussed in relation to the known changes of cellular physiology, suggesting the usefulness of concanavalin A-specific agglutination as a probe for the study of cell membrane topography.
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II. Specific Complex of Yeast Ribosomal RNA
Kazuo YANAGI, Koujiro ISO
1974 Volume 76 Issue 1 Pages
73-79
Published: July 25, 1974
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1. The anomalous heavier 30S RNA extracted from the ribosomes of baker's yeast (
Saccharomyces cerevisiae) is considered to be a hydrogen-bonded complex of one molecule each of 26 and 18S rRNA.
2. Addition of EDTA during the preparation of RNA from ribosomes by the bentonite-phenol method results in the extraction of a relatively large amount of 30S RNA. Treatment of a mixed solution of isolated 26 and 18S rRNA with phenol, in the presence of EDTA, failed to provide evidence for the formation of 30S RNA.
3. A specific complex is formed between 18 and 26S rRNA in a buffer containing 10mM Mg
2+.
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V. Mode of Action on Various Nucleotides
Yasutaro HAMAGISHI, Hiroshi YOSHIDA
1974 Volume 76 Issue 1 Pages
81-89
Published: July 25, 1974
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1. The rates of liberation of inorganic phosphate from eleven ribonucleoside monophosphates by
Fusarium phosphodiesterase-phosphomonoesterase were determined. Adenosine 3'-phosphate, guanosine 3'-phosphate, and cytidine 3'-phosphate are hydrolyzed at high rates, whereas guanosine 5'-phosphate, cytidine 2'-phosphate, and uridine 5'-phosphate are hardly cleaved.
2. All the ribonucleoside monophosphates competitively inhibit the hydrolysis of
p-nitrophenyl phosphate by the enzyme, with the exceptions of adenosine 5'-phosphate, guanosine 5'-phosphate, and cytidine 2'-phosphate, which are noncompetitive inhibitors. The apparent slope and intercept inhibition constants for each of the nucleotides were determined. Uridine 3'- and 5'-phosphates have particularly large values of the slope inhibition constant.
3. The rates of liberation of inorganic phosphate by the enzyme from eight ribonucleoside cyclic monophosphates were determined; those from adenosine 2', 3'-cyclic phosphate and guanosine 2', 3'-cyclic phosphate are high; and those from the four 3', 5'-cyclic phosphates are low. No intermediary phosphomonoester was detected in the course of hydrolysis of the cyclic phosphates, except for guanosine 3', 5'-cyclic phosphate, uridine 2', 3'-cyclic phosphate, and uridine 3', 5'-cyclic phosphate. These three yielded guanosine 5'-phosphate, uridine 3'-phosphate, and uridine 5'-phosphate, respectively, as intermediates.
4. Uridylyl-(3'-5')-adenosine was hydrolyzed by the enzyme into uridine, adenosine, and inorganic phosphate without release of any intermediary phosphomonoester. Adenylyl-(3'-5')-uridine, on the other hand, was cleaved into adenosine and uridine 5'-phosphate.
5. The terminal phosphate of adenylyl-(3'-5')-guanosine 3'-phosphate was eliminated rapidly by the enzyme, and the resulting dinucleoside monophosphate was then split into adenosine and guanosine 5'-phosphate. Cytidylyl-(3'-5')-guanosine 3'-phosphate and uridylyl-(3'-5')-guanosine 3'-phosphate behaved in much the same way, except that the splitting of the last dinucleotide was slower than those of the other two.
6. These results were interpreted in the light of the previously proposed mechanism for the action of phosphodiesterase-phosphomonoesterase.
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Hideo CHIBA, Koji IKURA, Ryuzo SASAKI, Etsuro SUGIMOTO, Hiroshi SAIMYO ...
1974 Volume 76 Issue 1 Pages
91-97
Published: July 25, 1974
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A direct method for simultaneously estimating the activity of phosphoglycerate mutase [EC 2. 7. 5. 3] and the concentration of 2, 3-diphosphoglycerate in tissue homogenates and in the hemolysates of mammals was established. By this method, a marked increase in the activity of phosphoglycerate mutase was observed in the red cells of patients with anemia and congestive heart failure, while the concentration of 2, 3-diphosphoglycerate was in the normal range.
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Tetsuhiko SHIRASAKA, Teruo ARIMA, Setsuro FUJII
1974 Volume 76 Issue 1 Pages
99-106
Published: July 25, 1974
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Nucleoside diphosphatase [EC 3. 6. 1. 6] from rat liver mitochondria was found to differ from that of microsomes in electrophoretic behavior.
A procedure was developed for purification of this enzyme from rat liver mitochondria. During the purification, it was found that on DEAE-cellulose column chromatography the mitochondrial enzyme separated into two fractions (Peaks A and B). Peak B was further separated into two components (Peak B
1 and B
2) by gel filtration on a Sephadex G-200 column. The molecular weights of Peak A, Peak B
1, and Peak B
2 were about 52, 000, 140, 000, and 52, 000, respectively.
ATP activated the microsomal enzyme and the enzyme of highest molecular weight (B
1) from mitochondria, but inhibited the enzymes of lower molecular weight (A and B
2) from mitochondria.
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XXI. Synthesis and Properties of Poly 1-Deazaadenylic Acid and Poly 3-Deazaadenylic Acid
Morio IKEHARA, Toshikazu FUKUI, Seiichi UESUGI
1974 Volume 76 Issue 1 Pages
107-115
Published: July 25, 1974
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Poly 1-deazaadenylic acid (poly 1-deazaA) and poly 3-deazaadenylic acid (poly 3-deazaA) were synthesized from 1-deaza and 3-deaza ADP by the use of
E. coli polynucleotide phosphorylase [EC 2. 7. 7. 8]. In the latter case, incubation was carried out at 60°C and in the presence of Mn
2+.
In neutral solution, poly 1-deazaA and poly 3-deazaA had hypochromicities of 42 and 32%, respectively. From the CD spectra and Tm profiles, a stacked conformation for both polynucleotides was assigned. Under acidic conditions poly 1-deazaA formed a protonated double-stranded complex, with Tm at 40°C. The acid form of poly 3-deazaA showed a Tm of over 80°C.
The mode of hydrogen bonding in the complex (poly 1-deaza A)•(Poly U) is suggested to be Hoogsteen type or reverse Hoogsteen type instead of the usual Watson-Crick type. By contrast, poly 3-deazaA formed both 1:1 and 1:2 complexes with poly (U) having Tm's of over 80°C.
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Akira OMORI, Hiroshi YOSHIDA, Nobuo TAMIYA
1974 Volume 76 Issue 1 Pages
117-121
Published: July 25, 1974
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1. Fractionation of 2'-5'GpGp and 3'-5'GpGp can be achieved by chromatography on a DEAE-Sephadex column in the presence of 7M urea. Elution was carried out with a linear gradient of NaCl from 0.14 to 0.28M.
2. Diguanylic acid synthesized from G-cyclic-p by RNase T
1 [EC 3. 1. 4. 8] has a 3'-5' phosphodiester linkage.
3. Spontaneous formation of a 2'-5' phosphodiester linkage occurs in the course of purification of G-cyclic-p during the desalting procedure on DEAF-cellulose in the presence of urea.
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Tomoh MASAKI, Chiho YOSHIZAKI
1974 Volume 76 Issue 1 Pages
123-131
Published: July 25, 1974
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Differentiation of myosin in chick embryos was studied by the fluorescent antibody technique:
1) Fluorescent antibodies against either the heavy chains of myosin from adult chicken breast muscle (fast white) or cardiac muscle stained both the breast muscle and cardiac muscle of early embryos. Staining of these muscles with the antibody against myosin from the other kind of muscle decreased as the embryos developed and no staining was observed after hatching. However, staining with antibody against myosin from the same kind of muscle did not decrease during development.
2) Essentially similar results to those described in 1) were obtained with troponin.
3) Fluorescent antibody against the heavy chain of myosin from adult anterior latissimus dorsi muscle (slow red) also stained both the breast muscle and cardiac muscle of early embryos. Staining gradually decreased during embryonic development. After hatching cardiac muscle did not stain while breast muscle showed small, clearly limited spots of stain.
4) Double staining with two of the three anti-myosin antibodies mentioned above revealed that single glycerinated myofibrils from 10 day chick embryos stained with all three antibodies.
5) The process of differentiation of embryonic myosins is discussed on the basis of these results.
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Nobuhito SONE
1974 Volume 76 Issue 1 Pages
133-136
Published: July 25, 1974
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A novel menaquinone has been isolated from
Propionibacterium arabinosum. Its ultraviolet-absorption spectrum is that of a typical manaquinone. The
E1%1cm value corresponds to that of MK-9, but it does not run with MK-9 on reversed-phase thin layer chromatograms. Mass spectra indicate that four additional hydrogen atoms are present as compared to MK-9, so that two double bonds of the nine isoprene units in the side chain are saturated. Hence the compound is designated MK-9 (4H) and a structure is proposed.
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IV. Participation of Menaquinone in the Electron Transfer System in Propionibacterium arabinosum
Nobuhito SONE
1974 Volume 76 Issue 1 Pages
137-145
Published: July 25, 1974
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The functions of menaquinone in the electron transfer system in
Propinoibacterium arabinosum were examined.
1. Activities for reactions such as NADH oxidation, fumarate reductions with MADH, glycerol-P and lactate, and the glycerol-P dehydrogenase reaction were rapidly lost when the membrane preparation from
P. arabinosum was irradiated with near-UV light. The lost activities were recovered by the addition of MK-4 as well as MK-9(4H), a manaquinone from the bacteria.
2. The abilities of different quinones to restore glycerol-P dehydrogenase activity were compared. The order of effectiveness was; MK-9(4H)>>MK-9(2H)_??_MK-6-10>MK-4_??_phylloquinone (vitamin K
1)>menadione>>ubiquinone_??_0.
3. The content of menaquinone in the membrane fraction was 4-7nmoles/mg protein, based on measurement of the oxidation-reduction difference spectra. MK-9(4H) was reduced by oxidizable substrates such as glycerol-P and lactate, but not by succinate, and was oxidized by fumarate. On the other hand, cytochrome
b was reduced by succinate as well as glycerol-P and lactate, and was oxidized by fumarate.
4. After irradiation with near-UV light, cytochrome
b was not reduced by glycerol-P and NADH, as it had been before, while reduction by lactate and succinate occurred as before.
5. Based on these observations, a scheme including MK-9(4H) is presented for the electron transfer system of
P. arabinosum.
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II. Modification of Amino Acid Residues in Inhibitor III
Taro OGISO, Sumihiro TAMURA, Yoshio KATO, Mamoru SUGIURA
1974 Volume 76 Issue 1 Pages
147-156
Published: July 25, 1974
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To clarify the character of the functional groups of a trypsin inhibitor from a sweet potato, chemical modification of the inhibitor and kinetic studies of the modified inhibitor have been carried out. As a result of these studies, it was found that antitryptic and antiplasmic activities were only slightly affected by modification of two amino groups, one sulfhydryl and two tryptophanyl residues in the inhibitor. It was shown, however, that the inhibitor partially lost antitryptic activity on nitration of two tyrosyl residues, whereas modification of one tyrosyl residue enhanced the inhibitory activity, and that the activity significantly decreased on modification of one arginyl, one histidyl and some carboxyl groups. This suggests that the functional groups of the inhibitor which are involved in the interaction with trypsin [EC 3. 4. 21. 4] are at least one arginyl, one histidyl and several carboxyl groups in addition to one tyrosyl residue. The
Ki for the complex between trypsin and the inhibitor in which one histidyl or some carboxyl groups were modified was found to be greater than that of the native inhibitor, while
Kifor the complex between the enzyme and the inhibitor with one tyrosine modified or one tryptophan modified decreased. It was found that the effect of chemical modification on the antiplasmic activity of the inhibitor was less than on the antitryptic activity, although inhibitor in which two histidyl residues were modified showed antiplasmic activity reduced almost to zero. These data suggest the existence of many bonds between the two moieties involved in the complex.
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III. Partial Purification of the Fraction I Activating Enzyme and the Occurrence of Two Forms of Fraction II
Seiji HAYASAKA, Syozo TUBOI
1974 Volume 76 Issue 1 Pages
157-168
Published: July 25, 1974
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The activating enzyme of the inactive form of Fraction I of
Rhodopseudomonas (
R.)
spheroides δ-aminolevulinate (ALA) synthetase [EC 2. 3. 1. 37] was purified about 150-fold from extracts of
R. spheroides cells grown anaerobically in the light. L-Cystine was also required for the enzyme-catalyzed conversion of the inactive form to the active form. The enzyme activity was lost completely when the enzyme was heated at 100°C for 2min or was treated with trypsin. The initial rate of conversion of the inactive form to the active form was dependent on the concentration of the inactive form, exhibiting a hyperbolic saturation curve. The activity of the activating enzyme in cells grown aerobically in the dark was far lower than in cells grown anaerobically in the light. The activating enzyme may be an inducible enzyme, like ALA synthetase in
R. spheroides.
When purified Fraction II was preincubated with L-cystine and the acetone fraction (from the third purification step for Fraction I activating enzyme), the specific activity of Fraction II increased remarkably. DEAE-Sephadex column chromatography of purified Fraction II which was preincubated with L-cystine and the acetone fraction revealed that the Fraction II had been converted to a more active form, The activation of Fraction II appeared to be catalyzed by some enzyme in the acetone fraction, but not by the Fraction I activating enzyme. The apparent molecular weights of both forms of Fraction II were estimated to be about 67, 000 by gel-filtration on Sephadex G-200.
The inhibitory effect of heroin and Mg-protoporphyrin on the four forms of ALA synthetase were studied. The most sensitive form to hemin was the active form The of Fraction I (50% inhibition at 3×10
-8M and 90% inhibition at 3×10-
7M). Moreover, the inhibition by heroin of the other three forms of ALA synthetase was only partial,
i.e., the extents of inhibition were less than 50% even at levels of heroin as high as 1×10
-6M. On the other hand, the most sensitive form to Mg-protoporphyrin was the active form of Fraction II. The concentrations of Mg-protoporphyrin required for 50% inhibition were 3.5×10
-6M and 1×10
-5M for the active form of Fraction II and the other three forms of ALA synthetase, respectively.
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XXII. Dissociation and Reconstitution of Spinach Leaf Ribulose-1, 5-diphosphate Carboxylase
Mikio NISHIMURA, Takashi AKAZAWA
1974 Volume 76 Issue 1 Pages
169-176
Published: July 25, 1974
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Upon treatment with
p-mercuribenzoate under alkaline conditions, spinach leaf ribulose-1, 5-diphosphate carboxylase [EC 4. 1. 1. 39] dissociates into its constituent subunits. A partial reassociation of the dissociated components into the native enzyme molecule (18S), with concomitant recovery of the enzyme activity, can be achieved by the addition of excess β-mercaptoethanol to the unfractionated subunits. The reversible nature of the dissociation was studied by means of sedimentation experiments in an analytical ultracentrifuge and also by sucrose density gradient centrifugation and polyacrylamide gel electrophoresis. The extent of the reassociation of the dissociated components into the native enzyme was 30-35%, recovering a specific activity about 80% that of the intact native enzyme. Among other thiol compounds tested, dithiothreitol was superior to β-mercaptoethanol, about 37% recovery of the original enzyme activity being attained, while reduced glutathione was least effective. The partial reconstitution of the original carboxylase molecule from the separated constituent subunits was established by observing the activating effect (50%) of the smaller subunit on the enzyme activity conveyed by the catalytic subunit, A
8 in concomitant reformation of the original native enzyme molecule, as determined by polyacrylamide gel electrophoresis.
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III. Non-helical Regions of the Collagen Molecules
Toshihiko HAYASHI, Yutaka NAGAI
1974 Volume 76 Issue 1 Pages
177-186
Published: July 25, 1974
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The interaction between acid-soluble collagen and pepsin-treated collagen during the course of fibril formation
in vitro was examined. The apparent rates of fibril formation from acid-soluble collagen and pepsin-treated collagen increased as the initial concentration of collagen was raised. However, when the total collagen concentration was increased by the addition of pepsin-treated collagen to a solution of acid-soluble collagen whose concentration was kept constant, the rate of fibril formation was reduced in 0.15M phosphate buffer (pH 6.8). It was thus suggested that the added pepsin-treated collagen interacted with the acid-soluble collagen as a “competitive” inhibitor of fibril formation under the conditions employed. Based on these and other observations, the following model was suggested for the process of collagen fibril formation. Collagen molecules in solution interact with one another to produce a loosely bound aggregate which is then transformed gradually to another aggregate (nucleus). The nucleus thus produced is capable of binding other collagen molecules to complete the fibril formation. This model is consistent with that proposed by Wood in that the rate of fibril formation is controlled by the incorporation of a collagen molecule to a growing fibril but not by the diffusion of a collagen molecule onto the surface of the fibril.
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Makoto KAWAKAMI, Tetsu KAKUTANI, Seiichi ISHIZUKA
1974 Volume 76 Issue 1 Pages
187-190
Published: July 25, 1974
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The posterior silk gland of silkworm,
Bombyx mori, L., contains two major tRNA
Met species. Only one species can be formylated with N
10-formyltetrahydrofolate using
Escherichia coli enzyme. The product has been identified as N-formyl-methionyl-tRNA.
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I. Immobilization of Carboxypeptidase CN, a Preparation from Citrus natsudaidai HAYATA
Hiroshi UEKI, Sumiyoshi NAGAI, Shozo SHOJI, Takayuki FUNAKOSHI, Yukiho ...
1974 Volume 76 Issue 1 Pages
191-199
Published: July 25, 1974
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Carboxypeptidase CN (CPase CN
*) [EC 3. 4. 12. 1], a preparation from the exocarp of
Citrus natsudaidai HAYATA, was immobilized by conjugating the enzyme to AE-cellulose through glutaraldehyde at various pH values with or without pretreatment with a competitive inhibitor, β-phenylpropionic acid. The inhibitor did not protect the enzyme from some loss of activity on immobilization. The specific activity toward Z-Glu-Phe of the preparation (AEC-CPase CN) obtained by conjugation at pH 6.0 without pretreatment with the inhibitor ranged from 24.0 to 59.6% of the activity of native CPase CN. The relative activities of AEC-CPase CN toward N-substituted dipeptides, expressed as a percentage of the activity toward Z-Glu-Phe, were higher than those of native CPase CN, although the specific activities of the former were lower than those of the latter. The values of
Km,
Vmax, and apparent activation energy for AEC-CPase CN were lower than those for native CPase CN. AEC-CPase CN could be stored at 4°C in 0.1M citrate buffer, pH 5.5, for five months with virtually no loss of activity. It possessed activities corresponding to 74 and 47% of its original activity after seven successive assays performed at 35 and 50°C, respectively. It removed four amino acid residues sequentially from the C-terminus of oxidized lysozyme [EC 3. 2. 1. 17].
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Takaaki KOBAYASHI
1974 Volume 76 Issue 1 Pages
201-204
Published: July 25, 1974
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Tadashi INOUE, Yasukiyo UMEMURA, Hikoyuki YAMAGUCHI
1974 Volume 76 Issue 1 Pages
205-207
Published: July 25, 1974
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Susumu HONDA, Hidetaka YUKI, Kiyoshi TAKIURA
1974 Volume 76 Issue 1 Pages
209-211
Published: July 25, 1974
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Shigehisa HIROSE, Nakatsugu YAGINUMA, Yuji INADA
1974 Volume 76 Issue 1 Pages
213-216
Published: July 25, 1974
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Michio YAZAWA, Fumi MORITA
1974 Volume 76 Issue 1 Pages
217-219
Published: July 25, 1974
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Ineo ISHIZUKA, Tamio YAMAKAWA
1974 Volume 76 Issue 1 Pages
221-223
Published: July 25, 1974
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Hisako FUSHIMI, Seiichiro TARUI
1974 Volume 76 Issue 1 Pages
225-227
Published: July 25, 1974
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Hiroyuki KONDO, Makoto ISHIMOTO
1974 Volume 76 Issue 1 Pages
229-231
Published: July 25, 1974
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Tatsuo OKU, Kazuo HOSOI, Gilbu SOE, Tornisaburo KAKUNO, Takekazu HORIO
1974 Volume 76 Issue 1 Pages
233-235
Published: July 25, 1974
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Masaaki MASUBUCHI, Zensaku YOSIZAWA
1974 Volume 76 Issue 1 Pages
237-239
Published: July 25, 1974
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1974 Volume 76 Issue 1 Pages
e1a
Published: 1974
Released on J-STAGE: November 18, 2008
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1974 Volume 76 Issue 1 Pages
e1b
Published: 1974
Released on J-STAGE: November 18, 2008
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