title: [Study of the enzyme activity of serum cystine aminopeptidase in man and animals in relation to the pH of the medium].
abstract: The authors studied the splitting dynamics of the synthetic chromogenic substrate (S-benzyl-L-cysteine-p-nitroanilide) specific of serum cystine aminopeptidase, depending on a wide range of pH (from 2.5 to 8.0) by means of an enzymatic serum system of pregnant women and selected animals (sheep, cows, sewer-rats), compared with non-pregnant controls. Examining the form of the enzymatic activity curves of the enzymatic system of women's and animal serum in dependence on pH, the authors revealed a characteristic bell-shaped course of the curve in the serum of pregnant women, as distinct from the sera of animals; the activity of cystine aminopeptidase in cows shows a two-peak course at pH from 3.5 to 4.0 and at pH from 6.5 to 7.0 while other animal species show irregularities with signs of the second peak. It follows from the results of the experiment that the main difference between pregnant and control animals is not the general increase of cystine aminopeptidase but a shift of the occurrence, or an increase of enzymatic activity at the given pH. The highest levels of cystine aminopeptidase were found in the blood sera of sewer-rats and lower in sheep and cows.
mesh_terms: D000626:Aminopeptidases / Q000097:blood*; D000818:Animals; D002417:Cattle / Q000378:metabolism; D003553:Cystine; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011247:Pregnancy; D051381:Rats / Q000378:metabolism; D012756:Sheep / Q000378:metabolism
chemical_list: D003553:Cystine; D000626:Aminopeptidases
vernacular_title: Stúdium enzymatickej aktivity sérovej cystínamínopeptidázy cloveka a zvierat v závislosti od pH prostredia