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201.
Teiichiro Ito Tadao Ishii Motohiro Nishio 《Bioscience, biotechnology, and biochemistry》2013,77(8):728-731
α-Methylthio-cinnamic acid and its substituted analogues (III) were synthesized from their respective β-aryl-α-thiopyruvic acids (II). In connection with the study on the tautomeric ene-thiol structure of β-aryl-α-thiopyruvic acids (II), 4-arylidenerl,3-oxathiolan-5-one (IV) were prepared from compounds II. 相似文献
202.
2-Acetamido-3,4-di-Oacetyl-2,6-dideoxy-6-S-acetyl-6-thio-d-glucopyranosyl chloride (III) was condensed with potassium thiolacetate, potassium ethylxanthate or thiourea to give three crystalline derivatives of 2-acetamido-2-deoxy-1,6-dithio-d-glucose. An attempt to prepare 2-acetamido-1,2,6-trideoxy-1,6-dimercapto-D-glucose (VII) from 2-acetamido-3,4-di-O-acetyl-1,2,6-trideoxy-1,6-di-S-acetyl-1,6-dithio-β-d-glucopyranose was described. 2-Acetamido-3,4-di-O-acetyl-1,2,6-trideoxy-1-mercapto-6-S-acetyl-6-thio-β-d-glucopyranose (VIII) was synthesized from the condensation product of III with thiourea. 相似文献
203.
Akira Murata Mamoru Odaka Syoichi Mukuno 《Bioscience, biotechnology, and biochemistry》2013,77(2):477-478
Some physicochemical properties and substrate specificity of acid protease B isolated from Scytalidium lignicolum were investigated.The molecular weight determined by the sedimentation equilibrium and sedimentation velocity method was 21,000 and 19,000~20,000, respectively. The isoelectric point was determined as 3.0 using the Tiselius electrophoresis apparatus, 3.2 by isoelectric focusing, respectively.The enzyme did not contain histidine and was composed of 188 amino acid residues. Substrate specificity against various synthetic peptides was different from those of the acid proteases which were inactivated by S–PI and DAN. 相似文献
204.
Yasumasa Kuwahara Hidetoshi Hara Shoziro Ishii Hiroshi Fukami 《Bioscience, biotechnology, and biochemistry》2013,77(3):447-448
Lachrymatory factor synthase (LFS), an enzyme essential for the synthesis of the onion lachrymatory factor (propanethial S-oxide), was identified in 2002. This was the first reported enzyme involved in the production of thioaldehyde S-oxides via an intra-molecular H+ substitution reaction, and we therefore attempted to identify the catalytic amino acid residues of LFS as the first step in elucidating the unique catalytic reaction mechanism of this enzyme. A comparison of the LFS cDNA sequences among lachrymatory Allium plants, a deletion analysis and site-directed mutagenesis enabled us to identify two amino acids (Arg71 and Glu88) that were indispensable to the LFS activity. Homology modeling was performed for LFS/23–169 on the basis of the template structure of a pyrabactin resistance 1-like protein (PYL) which had been selected from a BLASTP search on SWISS-MODEL against LFS/23–169. We identified in the modeled structure of LFS a pocket corresponding to the ligand-binding site in PYL, and Arg71 and Glu88 were located in this pocket. 相似文献
205.
2-Chlorophenyl N-methylcarbamate was determined colorimetrically. It was hydrolyzed with a veronal buffer solution (pH 8.0) to give corresponding 2-chlorophenol, which was coupled 4-nitrobenzenediazonium fluoroborate to produce a color having a maximum absorption at 520 mμ. The developed color was very stable. On the other hand, contaminated 2-chlorophenol was adsorbed in treated alumina before being hydrolyzed. Other contaminated impurities gave little influences. Technical materials and some formulated products were determined and good results were obtained. 相似文献
206.
Tsutomu Yamaguchi Noriyuki Muroya Masakazu Isobe Mamoru Sugiura 《Bioscience, biotechnology, and biochemistry》2013,77(5):999-1005
Out of some 750 strains of microorganisms, a potent bacterium for lipase production was isolated from soil and was identified as Chromobacterium viscosum.The bacterium accumulates lipase in culture fluid when grown aerobically at 26°C for 3 days in a medium composed of soluble starch, soy bean meal, lard and inorganic salts.Chromobacterium lipase had an optimum pH of 7.0 for activity at 37°C, and an optimal temperature of 65°C at pH 7.0. The enzyme retained 80% of the activity when heated for 10 min at 70°C. This lipase was capable of hydrolyzing a variety of natural fats and oils, and it was more active on lard and butter than on olive oil. The activity was stimulated by Ca2+, Mg2+, Mn2+ and inhibited by Cu2+, Hg2+ and Sn2+. It was not diminished but rather stimulated by a high concentration of bile-salts. 相似文献
207.
Ken-Ichi Nunami Mamoru Suzuki Kazuo Matsumoto Naoto Yoneda Kazuo Takiguchi 《Bioscience, biotechnology, and biochemistry》2013,77(4):1073-1075
We investigated GroEL substrates from Bacillus subtilis 168 using the single-ring mutant of B. subtilis GroEL. We identified 28 candidates for GroEL substrates, of which Spo0B, Ald, Eno, SpoIIP, and FbaA were involved in spore formation, and Rnc, Tuf, Eno, Tsf, and FbaA were essential for B. subtilis growth. As observed at the protein level, the amount of SpoIIP interaction with GroEL increased at 3 h after initiation of sporulation. 相似文献
208.
Masaki Nakahara Nobuaki Kitahara Kiyoshi Hamano Mamoru Arat Hiroshi Okazaki 《Bioscience, biotechnology, and biochemistry》2013,77(9):1821-1826
Studies on lipopolysaccharide (LPS) from the cells of Proteus mirabilis RMS-203 were focused upon reduction of lethal toxicity and of pyrogenicity by biological and chemical modification. A heptoseless mutant, strain N-434, was isolated by the use of phage resistancy as a tool. LPS from that heptoseless mutant was completely deficient in neutral sugars and mainly composed of 2-keto-deoxy-octonic acid (KDO), glucosamine and fatty acids. It revealed almost the same antitumor activity as LPS of the wild type but it was less toxic and less pyrogenic.Hydroxylaminolysis and reduction with LiAlH4 resulted in removal of fatty acids from LPS accompanied with decrease in lethal toxicity and antitumor acitivity but not in pyrogenicity.Lipid A fractions showed almost the same antitumor activity as intact LPS but less lethality and less pyrogenicity. 相似文献
209.
Mamoru Arai Masaki Nakahara v Hamano Hiroshi Okazaki 《Bioscience, biotechnology, and biochemistry》2013,77(9):1813-1819
Systematic isolation of the cell constituents of Proteus mirabilis RMS–203 was performed to find out localization of antitumor principle only in the lipopolysaccharide (LPS) layer of the cell wall fraction.LPS with strong antitumor activity was extracted from P. mirabilis RMS–203 by phenol-water method followed by purification on DEAE-Sephadex A–50 column chromatography.The main components of purified LPS were galactose, hexosamine, 2-keto-deoxy-octonic acid (KDO), myristic acid, β-hydroxymyristic acid and α,ε-diaminopimelic acid.The minimal effective dose of LPS against Ehrlich solid carcinoma in mice was 0.1~1.0 μg/mouse. LD50 in mice and pyrogenicity in rabbits were 28 mg/kg and 10?3–10?5 μg/rabbit, respectively. 相似文献
210.
Akihiro Okitani Yuzuru Otsuka Mamoru Sugitani Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(3):573-579
The properties of the neutral proteolytic activity concentrated in a fraction (F–1) separated from rabbit muscle homogenate were examined by measuring the effects of various reagents and metal ions, the time course of the proteolysis and Ca-stability. The obtained results have indicated that F–1 contains two types of neutral protease active on proteins, tentatively named Protease I and II, The former, which is activated by Ca2+ and Ca-labile, shows an explosive production of Cu-Folin phenol reagent positive materials at the early stage of incubation. The latter, which is Ca-stable, shows a large production of ninhydrin positive materials throughout the incubation time. The proteolysis by F–1 was similar to the autolysis of muscle homogenate in all the properties examined. Therefore, Proteases I and II were assumed to be main enzymes responsible for the muscle proteolysis at the neutral pH region. As there has been no factor denying their functioning in living muscle, it is probable that Proteases I and II take important parts in the muscle catabolism. 相似文献