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Biomedical subjects

S Kuwabara

Publications and source records attributed to S Kuwabara.

At least 199 records · Page 11Linked to original sources
PubMed1975

Amino acid sequence of tuberculin-active protein from Mycobacterium tuberculosis.

The complete amino acid sequence of tuberculin-active protein from tubercle bacilli was determined. The sequences of residues of tryptic, chymotryptic, and peptic peptides were established by Edman degradation and dansylation (5-dimethylaminonaphthalene-1-sulfonyl) and by digestion with carboxypeptidases A and B. Certain peptides were further degraded using partial acid hydrolysis. The aspartyl and glutamyl residues at positions 70 and 73 are present as amides. There is one intrachain disulfide bridge linking residues 27 and 59; there are no free sulfhydryls.

Amino Acid Sequence↗
PubMed1971

Protein and carbohydrate moieties of a preparation of -lactamase II.

1. A crystalline preparation of beta-lactamase II has been separated into two moieties by gel filtration on a column of Sephadex G-100. 2. The first moiety consisted mainly of carbohydrate and showed virtually no beta-lactamase activity. 3. The second moiety was a protein of molecular weight 22500, which was enzymically active. 4. The protein moiety, like the original protein-carbohydrate complex, required Zn(2+) for beta-lactamase activity. It did not differ significantly from the complex in its behaviour to a number of cephalosporin substrates, but was less stable to heat than the complex. 5. About 30% of the total beta-lactamase activity was lost when the protein-carbohydrate complex was separated into the two moieties. This activity was regained when the protein and carbohydrate moieties were mixed, but the mixture did not show the heat stability of the original complex.

Amino Acids↗
PubMed1970

Purification and properties of two extracellular beta-lactamases from Bacillus cereus 569-H.

1. When Bacillus cereus 569/H was grown in a casamino acid (casein-hydrolysate) medium containing zinc sulphate rapid production of extracellular beta-lactamase II preceded that of beta-lactamase I. 2. beta-Lactamase I was separated from beta-lactamase II by fractional precipitation with ammonium sulphate. 3. beta-Lactamase I was purified by a process involving chromatography on Celite and DEAE-cellulose and beta-lactamase II by chromatography on DEAE-cellulose after denaturation of beta-lactamase I by heat. Both enzymes were obtained in crystalline form. 4. beta-Lactamase II prepared in this way appeared to have a higher molecular weight than beta-lactamase I and required Zn(2+) as a cofactor for both cephalosporinase and penicillinase activities.

Bacillus cereus↗
PubMed1970

The composition of beta-lactamase I and beta-lactamase II from Bacillus cereus 569-H.

1. Crystalline beta-lactamase I from Bacillus cereus 569/H yielded only amino acids on acid hydrolysis, but crystalline beta-lactamase II from the same organism yielded also substantial quantities of neutral sugars and amino sugars. 2. Analysis with an amino acid analyser indicated that the two enzymes were similar though not identical in overall amino acid composition. Analysis of neutral and amino sugars as their silyl derivatives by gas-liquid chromatography showed that the carbohydrate moiety of beta-lactamase II contained residues of glucose, galactose, mannose, fucose, glucosamine and galactosamine. 3. After oxidation and hydrolysis both beta-lactamases gave small amounts of cysteic acid. After treatment of inactive Zn(2+)-free beta-lactamase II with N-ethylmaleimide or iodoacetate enzymic activity was not restored by the addition of Zn(2+).

Amino Acids↗