The present study intended to verify activities of cysteine proteinase of Pneumocystis carinii from rats and to purify the enzyme. In order to exclude the contamination of host-derived enzymes, concentrates of P. carinii was primarily treated with a mixture of proteinase inhibitors before lysis of P. carinii. A 68-kDa cysteine proteinase was finally purified from the crude extract of P. carinii...

Selenocysteine, the selenium analog of cysteine, was identified in proteins of Vigna radiata (L.) Wilczak grown with selenate. To stabilize selenocysteine and prevent its breakdown, the carboxymethyl derivative was synthesized by the addition of iodoacetic acid to the protein extract from [(75)Se]selenate-grown plants. A (75)Se-labeled component of the carboxymethylated protein hydrolysate poss...

Glycerinated chicken muscle was stained with antimyosin antibody conjugated with mercury and fluorescein. The antibody was visualized in both the electron and the fluorescence microscope by using adjacent thin and thick sections. In order to make this possible, Araldite was used as the embedding medium. The mercury was reduced to metallic mercury in the electron beam and either migrated in the ...

Chromatographically homogeneous egg white lysozyme has been subjected under reduced pressure to 0.67-m.e.v. y-rays. At 37% destruction of enzymic activity, three inactive aggregates and one partially active fraction have been isolated by salt precipitation and chromatographic procedures. The aggregates, upon reduction with 2-mercaptoethanol and reaction with iodoacetic acid, give derivatives wi...

In this study, we examined the disposition, metabolism, and excretion of a novel cardioprotective agent, 3-(2,2, 2-trimethylhydrazinium)propionate dihydrate (MET-88), in rats. The disposition of MET-88 after oral and i.v. administration of 2, 20, and 60 mg/kg indicated that the pharmacokinetics of MET-88 were nonlinear. The profiles of radioactive MET-88 and total radioactivity in plasma were c...

A 17 kDa protein from Clonorchis sinensis adults was purified by a procedure including Sephacryl S-200 HR gel filtration and Q-Sepharose anion exchange chromatography. The protein was proved to be a cysteine protease as it showed hydrolytic activity toward Cbz-Phe-Arg-AMC in the presence of dithiothreitol and was inhibited by specific inhibitors such as iodoacetic acid or trans epoxy-succinly-L...

The accumulation of 2-deoxyglucose (2-DG), a glycolytic inhibitor, was investigated in a human nasal carcinoma cell line, RPMI-2650 and two of its drug-resistant variants (selected with taxol and melphalan) to assess manipulation of glycolytic potential as a selective means of reducing resistance. 2-DG uptake was increased 3-fold and 9.9-fold in taxol- and melphalan-resistant variants of RPMI-2...

Various derivatives of the peptide component of subtilisinmodified ribonuclease have been described (1). Changes were produced in one or more of the three primary amino groups on Residues 1 and 7 in the parent compound.1 A derivative, in which acetylation of all three amino groups had been effected, was the only one showing a significant change in ability to regenerate enaymic activity when mix...

A novel staphylolytic enzyme, ALE-1, is a glycylglycine endopeptidase produced by Staphylococcus capitis EPK1. ALE-1 possesses seven histidines. Chemical modification studies using diethylpyrocarbonate and iodoacetic acid suggested that a histidine or tyrosine residue(s) in the molecule is important for the organism's staphylolytic activity. All of the histidine residues, one tyrosine, and one ...

The reactivities of human plasma factor XIIIa toward iodoacetic acid and toward alpha-bromo-4-hydroxy-3-nitroacetophenone have been studied under conditions where this dimeric enzyme reacts with the reagents in half-of-the-sites fashion and under conditions where it reacts with the reagents in all-of-the-sites fashion. Direct measurements of alkylation of active site -- SH groups in the apparen...