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71.
From root extracts of Phryma leptostachya L. was isolated a new lignan. Its structure has been determined to be 1-acetoxy-2-(3,4-methylenedioxy)phenoxy-6-(2-methoxy-4,5-methylenedioxy)phenyl-3,7-dioxabicyclo[3.3.0]octane on the basis of the chemical properties and spectra of its degradation products. 相似文献
72.
Hiroyuki Kumagai Masashi Matsue Eiji Majima Katsumi Tomoda Eiji Ichishima 《Bioscience, biotechnology, and biochemistry》2013,77(4):981-985
The specificity of highly purified carboxyl proteinase from Pycnoporus coccineus (formerly designated Trametes sanguined) was investigated with oligopeptides at pH 2.7. Hydrolysis of oxidized insulin peptide Bl ~ B16 was observed at two peptide bonds (His10-Leu11 and Ala14-Leu15) during 3-hr incubation. The enzyme did not hydrolyze oxidized insulin peptide B15 ~ B24. Hydrolysis of angiotensin (formerly designated angiotensin II) was observed at the Tyr4-Ile5 bond. Hydrolysis of proangiotensin (formerly designated angiotensin I) was also at the Tyr4-Ile5 bond. In conclusion, peptide bonds which have a hydrophobic amino acid in the P′1 position (as defined by Schechter and Berger, Biochem. Biophys. Res. Commun., 27, 157 (1967)) are preferentially cleaved by the trypsinogen activating carboxyl proteinase of Pycnoporus coccineus. 相似文献
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Miyagawa Eiji Junko Yano Toshinari Hamakado Yasuji Kido Keiji Nishimoto Yoshinobu Motoki 《Bioscience, biotechnology, and biochemistry》2013,77(10):2881-2886
N-Benzoylgiycine amidohydrolase (hippurate hydrolase EC 3.5.1.32), which catalyzes the hydrolysis of hippuric acid to benzoic acid and glycine, was found in a cell-free extract of Pseudomonas putida C692-3 grown on a medium containing hippuric acid. The enzyme was purified from the extract by ammonium sulfate fractionation and column chromatographies on DEAE-cellulose, DEAE-Sephadex A-50, hydroxyapatite, and Sepharose CL-6B. The enzyme was finally crystallized. The crystalline enzyme was almost homogeneous on electrophoresis. The enzyme had a molecular weight of about 170,000 and consisted of four subunits identical in molecular weight (approximately 42,000). The enzyme hydrolyzed N-benzoylglycine most rapidly, and N-benzoyl-l-alanine and N-benzoyl-l-aminobutyric acid. The Km value for these substrates were 0.72 mm, 0.87 mm, and 0.87mm, respectively. The optimum pH of the enzyme reaction was 7.0 to 8.0 and the enzyme was stable from pH 6.0 to 8.0. 相似文献
75.
Fumihiko Yoshida Michitaro Nagasawa Eiji Ichishima 《Bioscience, biotechnology, and biochemistry》2013,77(5):363-369
The specificity of crystalline Asp. Saitoi proteinase on oxidized lysozyme has been investigated by application of the Sanger DNP-method.It was found that this proteinase has a much broader specificity as compared with pepsin and Bac. subtilis proteinase. 相似文献
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79.
Shigeo Kawata Eiji Takahashi Yoshiyuki Takase Kanae Yokogawa 《Bioscience, biotechnology, and biochemistry》2013,77(12):2801-2808
d-Alanyl-(d)-meso-2,6-diaminopimelic acid endopeptidase was purified 47.4-fold with a yield of 40.5% from mutanolysin, which was partially purified from the cultural supernatant of Streptomyces globisporus 1829, by using ion exchange column chromatographies and a molecular sieve column. The purified enzyme was electrophoretically homogeneous. This enzyme had a molecular weight of 13,500 and an isoelectric point of pI 9.0. This enzyme was most active at pH 8.5 and stable between pHs 8.0 and 9.0. The hydrolyzing activity of this enzyme was enhanced by Co+ + and Ca+ + but inhibited appreciably by Zn+ +, Cu+ + and EDTA. The enzyme activity was not affected by β-lactam antibiotics and vancomycin. The Km values for bisdisaccharide heptapeptide and its derivative modified chemically by BOC-S were calculated to be 5.7 × 10-4 and 4.0 × 10-4 m, respectively. 相似文献
80.
Minoru Ameyama Kenji Tayama Eiji Miyagawa Emiko Shinagawa Kazunobu Matsushita Osao Adachi 《Bioscience, biotechnology, and biochemistry》2013,77(11):2063-2069
A new enzymatic method for microdetermination of ethanol has been established with particulate alcohol dehydrogenase from acetic acid bacteria and applied to the practical purposes. The enzyme had an optimum pH for ethanol oxidation at a fairly acidic region. Trace amounts of ethanol could be assayed by measuring the initial reaction rate as successful as by reading the end point of the reaction. Some advantages in using this enzyme for ethanol determination were pointed out comparing with NAD-linked alcohol dehydrogenase from yeast or horse liver. Impurity in the enzyme preparations, stability of reagents and coexistence of other substances in the assay mixture were not as critical as in NAD-linked enzyme. Acidic samples could also be directly determined for ethanol without preadjustment of sample pH. 相似文献