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Biomedical subjects

L Lorand

Publications and source records attributed to L Lorand.

At least 127 records · Page 7Linked to original sources
PubMed1972

Transamidase reactions involved in the enzymic coagulation of semen: isolation of -glutamyl- -lysine dipeptide from clotted secretion protein of guinea pig seminal vesicle.

New supportive evidence is advanced in favor of the hypothesis that the enzymic coagulation of guinea pig semen involves transamidase reactions that result in the formation of gamma-glutamyl-epsilon-lysine intermolecular cross linkages between molecules of a basic protein in seminal vesicle secretion. The dipeptide gamma-glutamyl-epsilon-lysine was isolated in large quantities from proteolytic digests of the coagulated basic vesicular secretion protein that comprises the seminal clot.

Amino Acids↗
PubMed1972

Thiolester substrates for transamidating enzymes: studies on fibrinoligase.

Esters of thiocholine were shown to inhibit the crosslinking of fibrin clots by the transamidating enzyme, fibrinoligase (thrombin-activated fibrin-stabilizing factor or activated Factor XIII). Inhibition depended on the nature of the acylating group with the phenylpropionyl, phenylbutyryl, and trans-cinnamoyl esters being most effective of the compounds tested so far. Use of the thiolesters made it possible for the first time to study the reactions of fibrinoligase in fully synthetic substrate systems. Enzyme-catalyzed acyl-group transfers from the thiol-esters to a fluorescent amine [N-(5-aminopentyl) - 5 - dimethylamino - 1 - naphthalenesulfonamide] could be readily demonstrated and measured.Trans-cinnamoylthiocholine reacted with fibrinoligase in a totally calcium-dependent manner in the absence of any added amine, thus providing the first evidence for an esterolytic pathway for this enzyme. Spectral qualities, as well as appreciable extent of solubility in water, would seem to make trans-cinnamoylthiocholine a specially suitable substrate for further studies.

Acylation↗