Naslov
Kinetics of the inhibition of human serum cholinesterase phenotypes with the dimethylcarbamate of (2-hydroxy-5-phenylbenzyl)-trimethylammonium bromide (Ro 02-0683)

Autori
Prester, Ljerka ; Simeon, Vera

Izvornik
Biochemical Pharmacology (0006-2952) 42 (1991), 12; 2313-2316

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
human serum cholinesterase; inhibition

Sažetak
The inhibition of the human serum cholinesterase phenotypes, usual (U), atypical (A) and heterozygous (UA), by the dimethylcarbamate of (2-hydroxy-5-phenylbenzyl)-trimethylammonium bromide (Ro 02-0683), was followed with benzoylcholine, acetyl-, butyryl- and propionyl-thiocholine as substrates. The first-order rate constants were calculated from the linear part of the inhibition curves and were independent of the substrate used for measuring the enzyme activity. The second-order rate constants for the U, UA and A phenotypes were 8.3 × 106, 6.1 × 106 and 0.05 × 106 M^− 1 min^− 1, respectively. The constant of the enzyme-inhibitor complex for the atypical serum was 7.7 μ M, and the rate of carbamylation of the enzyme was 0.386 min^− 1. The rate of reactivation of carbamylated usual and atypical enzyme was found to be same ; the half-time of reactivation was about 3.5 hr. The deviation from the linearity of the inhibition course was explained by spontaneous reactivation of the inhibited enzyme ; the theoretical inhibition curves were in good agreement with the experimentally obtained values. The three phenotypes could be distinguished by the rate of inhibition by the dimethylcarbamate, Ro 02-0683, in the progressive phase of inhibition or by the degree of inhibition in the apparent steadystate.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA