PubMed Health⌕ Search

Biomedical subjects

D Basu

Publications and source records attributed to D Basu.

At least 91 records · Page 5Linked to original sources

Failure of benzene and phenol to serve as substrates for the peroxidatic action of catalase.

Evidence from several reports in the literature indicates a possible role for catalase in the metabolism of benzene. To investigate possible peroxidatic activity of catalase on benzene or its major metabolite, phenol, we employed an in vitro assay system that had been used previously to study the peroxidation of ethanol by catalase. Under conditions identical to those used to demonstrate catalase-mediated ethanol peroxidation we observed no peroxidase activity of catalase toward either benzene or phenol. We conclude that catalase is not involved in benzene metabolism and make the observation that, to date, no aromatic compounds have been demonstrated to be substrates for the peroxidatic mode of action of catalase.

Animals↗

Application of the least-squares method in the matrix form: simultaneous spectrophotometric determination of rifampicin and isoniazid in binary pharmaceutical formulations.

A least-squares method in the matrix form is described for the simultaneous determination of rifampicin and isoniazid in a mixture. The method allows the rapid analysis of binary pharmaceutical formulations with minimum error. The concentration of each component in the mixture has been determined spectrophotometrically by measuring the absorbance of the mixture at 5-nm intervals from 230 to 290 nm. To calculate the matrix of the proportionality constant a standard mixture was used for each component. All data analyses were performed on a personal computer.

Isoniazid↗

Alpha-galactoside-binding isolectins from wild jack fruit seed (Artocarpus hirsuta): purification and properties.

Five isolectins with marked specificity for alpha-linked galactose were purified from the wild jack (Artocarpus hirsuta) seeds by affinity chromatography on cross-linked guar gum. They were composed of a glycosylated subunit A (Mr = 16 kDa) and a nonglycosylated subunit B (Mr = 11 kDa) in noncovalent association. The isolectins which eluted as a single peak of Mr 45 kDa on gel filtration in Biogel P-100 and in a TSK G-3000 SW high pressure column, were resolved into five peaks on electrophoresis at pH 4.5. Sodium dodecyl sulphate polyacrylamide gel electrophoreogram of the major isolectin band suggested that the isolectins may be the five possible tetrameric combinations of A and B subunits. The combined isolectins bound only two molecules of 4-methyl umbelliferyl alpha-D-galactoside with a binding constant of 4.75 x 10(4) M-1. The pH optimum of sugar binding was 7.0. The isolectins specifically bound to human IgG and IgA but not to IgM.

Electrophoresis↗

Preliminary crystallographic study of the alpha-D-galactose-specific lectin from jack fruit (Artocarpus integra) seeds.

Crystals of the alpha-D-galactose-specific lectin from Jack fruit (Artocarpus integra) have been obtained from polyethylene glycol 400 solutions. The crystals are orthorhombic, space group P2(1)2(1)2 with a = 77.09 A, b = 123.3 A and c = 78.73 A (1 A = 0.1 nm) and have one 39,500 Mr tetramer per asymmetric unit. The crystals diffract to at least 2.8 A on precession photographs.

Galactose↗