Sukharev S A, Pleshakova O V, Moshnikova A B, Sadovnikov V B, Gaziev A I
Branch of Shemyakin, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
Comp Biochem Physiol B Biochem Mol Biol. 1997 Mar;116(3):333-8. doi: 10.1016/s0305-0491(96)00232-5.
Soluble liver proteins (SLP) from old and gamma-irradiated young rats were studied with respect to their carbonyl content, the rates of autolysis and degradation by proteinase K, and their antigenicity for mice and compared with SLP from non-irradiated young animals. A significant increase in the carbonyl level was found in SLP from old and gamma-irradiated young rats as compared to SLP from intact young rats. The rates of SLP autolysis and proteolysis by proteinase K were increased in the same animal groups but did not correlate the carbonyl level. At the same time, whereas the antigenicity for mice of SLP from old rats was significantly higher than that of SLP from young rats, the antigenicity of SLP from gamma-irradiated rats did not differ from non-irradiated animals. Enrichment of the diet with antioxidant and vitamin supplements (AVS) during one month before the irradiation caused a decrease in the radiation-induced carbonyl level in rat SLP. However, this raised antioxidant level in animal diet did not influence the rates of SLP autolysis and degradation by proteinase K and also did not alter the antigenicity of these proteins. The data allow us to suggest that the increase in autolysis, degradation by the exogenous proteinase, and antigenicity of SLP from old rats are determined not only by carbonyl formation in these proteins due to action of oxygen radicals but also by other age-specific protein modifications.
研究了老年和γ射线辐照的幼年大鼠的可溶性肝蛋白（SLP），检测了其羰基含量、自溶速率以及被蛋白酶K降解的速率，并检测了其对小鼠的抗原性，同时与未辐照的幼年动物的SLP进行了比较。与完整幼年大鼠的SLP相比，老年和γ射线辐照的幼年大鼠的SLP中羰基水平显著升高。同一动物组中SLP的自溶速率和被蛋白酶K的蛋白水解速率均增加，但与羰基水平无关。同时，老年大鼠的SLP对小鼠的抗原性显著高于幼年大鼠的SLP，而γ射线辐照大鼠的SLP的抗原性与未辐照动物的无差异。在辐照前一个月用抗氧化剂和维生素补充剂（AVS）丰富饮食，可使大鼠SLP中辐射诱导的羰基水平降低。然而，动物饮食中这种升高的抗氧化剂水平并未影响SLP的自溶速率和被蛋白酶K的降解速率，也未改变这些蛋白质的抗原性。这些数据表明，老年大鼠SLP的自溶增加、被外源性蛋白酶降解以及抗原性增加，不仅是由于氧自由基作用导致这些蛋白质中羰基形成，还与其他年龄特异性的蛋白质修饰有关。
