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71.
In-Kyu Hwang Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(12):3049-3053
Some kinetic properties of a dipeptidase purified from a cell-free extract of Streptococcus cremoris H 61 were investigated. The Km values of this enzyme for various dipeptides were divided into 3 groups. Group 1 comprised mainly of neutral dipeptides, such as Leu-Gly, Leu-Leu and Leu-Ala, which had relatively low Km values (in the range 4.0-6.6 mm). Group 2 consisted of dipeptides with aromatic large amino acids either at the N- or C-terminal positions, like Leu-Phe, Phe-Ala and Leu-Tyr, which had very low Km values (in the range 1.0-2.4 mm). Group 3 was made up by dipeptides with acidic or basic amino acids at the N-terminals; His-Ala and Glu-Val were typical of this group. These had very high Km values (in the range 10–20 mm). Substantial substrate competition was found to exist in the presence of His-Ala. Bestatin inhibited the enzyme competitively with Leu-Gly and was found to have an apparent Ki value of 3.0 × 10?8 m for the enzyme. Further, the enzyme was completely inhibited by EDTA at a concentration of 2.0 × 10?5 m. On the other hand, once the activity was inhibited by EDTA, it could be restored by Co2+ and Zn2+ in the acidic pH side, and by Ca2+ and Mn2+ in the alkaline pH side. 相似文献
72.
Shuichi Ishino Kazuo Yamaguchi Kunikatsu Shirahata Kazumi Araki 《Bioscience, biotechnology, and biochemistry》2013,77(10):2557-2560
To characterize aspartyl aminopeptidase from Aspergillus oryzae, the recombinant enzyme was expressed in Escherichia coli. The enzyme cleaves N-terminal acidic amino acids. About 30% activity was retained in 20% NaCl. Digestion of defatted soybean by the enzyme resulted in an increase in the glutamic acid content, suggesting that the enzyme is potentially responsible for the release of glutamic acid in soy sauce mash. 相似文献
73.
Osamu Yamada Akira Kurozumi Fumio Futatsuya Kensaku Ito Shuichi Ishida Katsura Munakata 《Bioscience, biotechnology, and biochemistry》2013,77(7):1467-1471
Some benzophenones substituted with methyl, methoxy, hydroxy or halogen groups inhibited growth and induced chlorosis in various plants. The structure activity relationships about the chlorosis-inducing activity and the growth inhibitory activity of the 3-methyl-benzophenones were well expressed by use of hydrophobic contant π, and Hammett’s σ. The highest selectivity for phytotoxic activities against barnyardgrass and the rice plant was with 3,3′-dimethyl-4-methoxybenzophenone (Methoxyphenone). 相似文献
74.
Norihiro Azuma Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(9):2655-2660
Human casein micelles were reconstituted from isolated κ- and β-caseins and calcium ions. Micelle formation was recognized in the presence of calcium chloride even at the low concentration of 5mM. At pH levels ranging from 5.5 to 8.0, the re-formed micelles were quite stable so that precipitation of β-casein was not observed. The large micelles were constituted by a higher ratio of β-casein to κ-casein (16:1 by weight) than the small micelles (3: 1). The κ-casein in the small micelles contained carbohydrates to about 43% (w/w) in the molecule, whereas that in the large micelles was only about 25%. When the casein micelles were re-formed from κ-easein and fractionated β-casein components, the extent of phosphorylation of the β-casein component was found to influence the micelle formation; i.e., the β-casein component with no phosphate (the 0-P form) was disadvantageous to form micelles, but the component with 5 phosphates (the 5-P form) formed micelles most easily. 相似文献
75.
Shuichi Kaminogawa Shunichi Dosako Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(12):2337-2341
Some molecular properties of αs1-κ-casein complex, αs1- and κ-casein polymers were examined by gel filtration, ultracentrifugation, and viscometry at pH 7.1. The Stoke’s radii of αs1-κ-casein complex, αs1- and κ-casein polymers were 99, 44 and 108 Å, respectively. The molecular weight of the above proteins were approximately 45 × 104, 10 × 104 and 80 × 104, respectively. The stokes radius of αs1-κ casein complex reduced compared with that of κ-casein polymer and the molecular weight of the complex was about half that of κ-casein polymer. These results suggest that κ-casein polymer dissociates into 4 smaller particles when αs1-κ-casein complex is formed. The frictional coefficient and Scheraga-Mandelkern constants for each protein suggest that the molecular shape of αs1-casein polymer is globular and that of αs1-κ-casein complex and κ-casein polymer is rod-like. 相似文献
76.
Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(12):2343-2348
A γ-casein-like fraction (FIV) was isolated from the β-casein A hydrolyzate by milk protease and compared with γ-casein. The mobility in polyacrylamide gel electrophoresis, sedimentation coefficient, molecular weight, amino acid composition and terminal amino acids of FIV were almost coincided with those of γ-casein. It is suggested that γ-casein is possibly a product of β-casein hydrolysis by milk protease. 相似文献
77.
Shuichi Ishida Mitsuo Ida Osamu Yamada 《Bioscience, biotechnology, and biochemistry》2013,77(4):410-421
Formation of a sulfonium-like intermediate was assumed in the hydrolysis of the 2-bromoethylthiobenzenes. A linear free energy relationship was found between the hydrolysis rate of a certain substituted 2-bromoethylthiobenzene and the molar fraction of water in the solvent. The effect of the substituent on the rate constant was attributed not only to the activation energy but also to the entropy change of activation. The negative ρ-value in the formation of the sulfonium-like intermediate in aqueous solution was comparable with that obtained in the ρ-σ-π analysis for ovicidal activity of the compounds.For the reaction of the substituted 2-bromoethylthiobenzenes with highly excess amount of 4-(p-nitrobenzyl)-pyridine, the ρ-value was found to be negative, which means that the formation of the sulfonium-like intermediate is a rate determining step. Whichever might be more important, the hydrolysis or alkylation, as to the ovicidal action of the compounds, the formation of the sulfonium-like intermediate, could be considered to be an essential step. 相似文献
78.
Tsuru Daisuke Hiraoka Nobutsugu Hirose Tsuneyo Fukumoto Juichiro 《Bioscience, biotechnology, and biochemistry》2013,77(11):1727-1732
Nine strains capable of producing dextranase were isolated from soil. Among them, a strain belonging to the genus Aspergillus was chosen as the best producer of the enzyme. The mold produced greater amounts of dextranase than those found in some strains in the genus Penicillium, when grown aerobically at 28°C for 5 to 6 days in medium containing 1% dextran, 1% NaNO3 or polypeptone, 0.2% yeast extracts, 0.4% K2HPO4 and small amounts of inorganic salts, pH 8.5. From the comparative taxonomic experiments, the mold used here was identified to be a strain belonging to Aspergillus carneus. 相似文献
79.
Osamu Yamada Shuichi Ishida Fumio Futatsuya Kensaku Ito Hiroshi Yamamoto Katsura Munakata 《Bioscience, biotechnology, and biochemistry》2013,77(6):1235-1240
The discovery that anisomycin showed plant growth-regulating activity led to the investigation of compounds having p-methoxyphenyl group; the p-anisole derivatives. 4-Methoxydiphenylmethanes and related compounds inhibited the growth of both shoots and roots in test plants. Growth-inhibitory activity in the series of 4-methoxydiphenylmethanes was lowered by an increase in the electron donating or withdrawing ability of the substituent and was parabolically dependent on the Hammett’s σ. Selective actions of these compounds in their growth inhibition are discussed based on correlations between their activities against barnyard grass and other test plants.Some 4-methoxydiphenylmethanes induced chlorosis, a disturbance in phototropism or geotropism, and root hypertrophy. 相似文献
80.
Norihiro Azuma Shuichi Kaminogawa Kunio Yamauchi 《Bioscience, biotechnology, and biochemistry》2013,77(8):2025-2031
The nutritional efficiency of quinolinic acid as a substitute for nicotinic acid was investigated using weanling rats Of the Sprague Dawley strain (3-weeks old) fed a nicotinic acid-free, tryptophan-limited diet containing various amounts of nicotinic acid or quinolinic acid. Judging from the growth response, food efficiency ratio, levels of NAD activity in the blood, liver, brain and upper small intestine, and urinary excretion of niacin we have concluded that exogenous quinolinic acid is approximately 1/9 as active as nicotinic acid. As many foods contain quinolinic acid, dietary quinolinic acid cannot be ignored from the standpoint of tryptophan and nicotinic acid replacement. 相似文献