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Biomedical subjects

C Danzin

Publications and source records attributed to C Danzin.

42 records · Page 3Linked to original sources
PubMed1978

Analogues of ornithine as inhibitors of ornithine decarboxylase. New deductions concerning the topography of the enzyme's active site.

Fourteen structural analogues of ornithine were synthesized and evaluated as inhibitors of preparations of the enzyme L-ornithine carboxylase (ODC) (E.C. 4.1.1.17) obtained from rat liver, rat hepatoma cells in culture, or bull prostate. The synthesis of these compounds was achieved either via a Bucherer type reaction or via alkylation of carbanions derived from ethyl acetamidocyanoacetate, methyl isocyanoacetate, benzyl alpha-isocyanopropionate, methylbenzaldimine alanate, and the azlactone derivative of ornithuric acid. (+)-alpha-Methylornithine, which was assigned the L configuration on the basis of rotational criteria, was found to be the most potent reversible inhibitor of ODC among the synthesized compounds. From the degree of inhibition of ODC activity in the presence of the various ornithine analogues, it has been possible to delineate some of the structural features of the substrate L-ornithine which are required for binding to the mammalian ODC active site.

Animals↗
PubMed1976

Deoxyribosyl transfer catalysis with trans-N-deoxyribosylase. Kinetic study of purine(pyrimidine) to pyrimidine(purine) trans-N-deoxyribosylase.

Kinetic studies were carried out in order to investigate the enzymic mechanism of a 215-fold-purified purine(pyrimidine) nucleoside: purine(pyrimidine) deoxyribosyl transferase fraction from Lactobacillus helveticus. A variety of natural deoxyribonucleosides and bases were used as substrates. Initial velocity, product inhibition and isotopic exchange studies are consistent with a ping-pong bi-bi mechanism. The kinetic parameters are used to show that this fraction is free from any contamination by a specific purine nucleoside: purine deoxyribosyl transferase also found in the same strain of L. helveticus.

Adenine↗