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Biomedical subjects

M Ledvina

Publications and source records attributed to M Ledvina.

At least 109 records · Page 6Linked to original sources
PubMed1969

Characteristics of beta-galactosidase in the mucosa of the small intestine of infant rats. Physicochemical properties.

1. The characteristics of acid and neutral beta-galactosidases isolated chromatographically from homogenates of the mucosa of the jejunum and ileum of suckling rats were studied. 2. The minimal molecular weight of the acid beta-galactosidase, as estimated by gel filtration on Sephadex G-200, was in the range 83000-105000, whereas for the neutral beta-galactosidase the estimated molecular weight was in the range 360000-510000. 3. The acid and neutral beta-galactosidases were inhibited competitively by galactono-(1-->4)-lactone, with respective K(i) values of 0.15mm and 1.1mm. Only the acid beta-galactosidase was inhibited competitively by sodium galactonate (K(i) 0.17mm). 4. Heat inactivation of both beta-galactosidases occurred according to first-order kinetics. The neutral enzyme was more labile, but bovine serum albumin protected acid enzyme only. 5. Urea treatment inactivated both beta-galactosidases, the neutral beta-galactosidase being more sensitive than the acid beta-galactosidase. 6. No differences were found between preparations from the jejunum and ileum.

Animals↗
PubMed1968

Differences in elastase hydrolysates of elastin from ligamentum nuchae.

By means of molecular exclusive chromatography, a marked difference in the distribution of desmosine and isodesmosine in the products of proteolysis has been found between the partial enzymatic hydrolysates of elastin from the bovine nuchal ligament prepared by two different methods. In the preparation which was treated with hot NaOH the prevailing portion was localized in a macromolecular fraction corresponding to the void volume. An increased precipitation of this fraction with trichloracetic acid has been noticed. The autoclaved material forms substantial amounts of the coacervate during the digestion.

Journal Article↗