Влияние биогенных фосфатов на расщепление белков протеиназами и функцию активаторов плазминогена

Abstract

We showed, using the method of lysis of fibrin plates and five substrate proteins in a thin layer of agar gel, that inorganic orthophosphate (0.001–0.06 M) enhances by 50–250% the activatory functions of streptokinase, urokinase, and tissue plasminogen activator and, in general, by 1.2–12.0 times enhances protein lysis by trypsin, α-chymotrypsin, subtilisin, papain, bacterial metalloprotease, and even pepsin at a concentration < 4 mM. At higher concentrations, phosphate sharply inhibited pepsin activity and inhibited by 40–50% gelatin lysis by papain and gelatin (at a peak concentration) and casein lysis by metalloprotease. Inorganic pyrophosphate ions at concentrations of 10–8–10–1 M enhanced the cleavage of a number of proteins by serine proteases and, at concentrations of 10–5–10–3 M, the activities of pepsin, plasminogen tissue activator, and streptokinase by 100 and 40%, respectively. The pyrophosphate concentrations of >10–3 and >10–4 M inhibited pepsin- and metalloprotease-induced lysis of virtually all proteins. ATP increased casein lysis by serine proteases, metalloprotease, and pepsin by 20–60% at concentration of 10–3 M and by 30–260% at 10–2 M concentration. At concentrations of 10–2 M, it inhibited the cleavage of some proteins by trypsin, chymotrypsin, papain, and metalloprotease by 20–100%, and, at concentrations of 10–3 M, lysis of albumin with pepsin and other proteins (except for fibrinogen) by metalloprotease. A GTP concentration of 10–7–10–2M increased protein degradation by serine proteases, papain, and gelatin lysis by pepsin by 20–90%, whereas albumin lysis was inhibited by 40−70%. The presence of 10–6–10–5 M GTP led to a slightly increased degradation of hemoglobin and casein by bacterial metalloprotease, while 10–3 M GTP induced a drop in the activity of the metalloprotease by 20−50%. ADP could enhance gelatin lysis by trypsin, casein lysis by pepsin and papain, and inhibited metalloprotease activity by 20–100% (at 10–3 M). Peculiarities of the effects of AMP and GD (M) P on gelatin lysis were found. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2008, vol. 34, no. 3; see also http://www.maik.ru