Search PubMed⌕ Search

Biomedical subjects

N S Radin

Publications and source records attributed to N S Radin.

At least 127 records · Page 7Linked to original sources
PubMed1973

Sexual differences in galactose metabolism: galactosyl ceramide galactosidase and other galactosidases in mouse kidney.

Male and female mice were compared at two ages, 15 and 50 days, with respect to the activities of three galactosidases in kidney. No sex difference in enzyme activity was seen in the young mice, but appreciable differences were found in the older animals. The male kidneys had about one-third higher specific activities of cerebroside beta-galactosidase and nitrophenyl beta-galactosidase, but there was no difference with nitrophenyl alpha-galactosidase. A listing and discussion of other galactose-metabolizing enzymes influenced by sex differences is presented.

Age Factors↗
PubMed1973

N-hexyl-O-glucosyl sphingosine, an inhibitor of glucosyl ceramide -glucosidase.

A synthetic analog of glucocerebroside, N-hexyl-O-glucosyl sphingosine, was found to inhibit the glucosidase in rat spleen that hydrolyzes glucocerebroside. At a concentration of 1 micro m, the analog inhibited the enzyme by 48%. The mode of action appeared to be competitive, probably aided by tight binding of the amine group to a carboxyl group near the enzyme's active site. Increasing or decreasing the chain length of the n-alkyl group attached to the nitrogen atom led to decreased effectiveness. The inhibitory effect was maximal at pH 7.0, but it was still considerable at the enzyme's optimal pH, 5.0. It is suggested that the compound may be useful for inducing an animal model of Gaucher's disease.

Alkanes↗
PubMed1972

Oxalate-silica gel thin-layer system for free 2-hydroxy fatty acids and for fatty acyl coenzyme A.

The 2-hydroxy fatty acids tend to yield streaks in thin-layer chromatography on silica gel plates. If potassium oxalate is included with binder-free silica gel, good spots are obtained. Similar difficulties are found in paper chromatography of the fatty acid derivatives of coenzyme A, especially with long-chain acids. The same thin-layer system gives good spots with these compounds.

Chromatography, Thin Layer↗
PubMed1972

Ceramide-like synthetic amides that inhibit cerebroside galactosidase.

Amides resembling ceramide (fatty acyl sphingosine) were synthesized and tested for their effects on rat brain cerebrosidase (galactosyl ceramide beta-galactosidase). The best inhibitor was N-decanoyl dl-erythro-3-phenyl-2-aminopro-panediol, which exhibited a K(i) of 0.4 mm. A Lineweaver-Burk plot indicated that the amide acted as a noncompetitive inhibitor, presumably by attachment to a site other than the substrate-active site. Preincubation did not affect the degree of inhibition, and inhibition was independent of incubation duration; these observations suggest that the inhibitor does not combine with the enzyme irreversibly. Structural variations produced decreased inhibitory activity: loss of one of the hydroxyl groups, replacement of the aromatic side chain with an aliphatic or substituted phenyl group, or isomeric inversion of the 3-hydroxyl group. It appears that the best activity is obtained with a substance most closely resembling natural ceramide. The cerebrosidases of rat spleen, kidney, and liver are also inhibited by the same amide.

Acylation↗
PubMed1971

A simplified assay method for galactosyl ceramide beta-galactosidase.

In a previously described method for determining the activity of cerebroside galactosidase, the enzyme preparation was incubated with an emulsion of cerebroside which had been labeled in the galactose moiety. The liberated galactose was separated from the emulsion by liquid-liquid partitioning, but the presence of detergent necessitated the use of careful agitation and a backwash in order to reduce the contamination of the aqueous layer with excess emulsified substrate. This problem is eliminated by adding a large amount of lipid to reduce the emulsifying power of the detergent. It may be that other lipid hydrolase assays, based on the same principle, would benefit by this approach. Some additional improvements in the assay system are described.

Bile Acids and Salts↗
PubMed1970

Rapid axonal transport of sulfated mucopolysaccharide proteins.

When sulfur-35-labeled sodium sulfate is injected intraocularly in the goldfish, labeled sulfated mucopolysaccharides rapidly appear in the contra-lateral optic tectum of the brain, demonstrating the axonal flow of sulfated mucopolysaccharides. The transport rate is the same as that observed for proteins labeled after intraocular injection of tritiated proline. Treatment of the sulfur-35-labeled material with precipitants and enzymes reveals the presence of substances with properties similar to those of heparan sulfate (the major component) and chondroitin sulfate. Dermatan sulfate was not detected.

Animals↗