ADP-Ribosylation Reaction in Rabbit Skeletal Muscle SR

研究了精氨酸特异性单核苷酸（adp -核糖基）在兔骨骼肌肌浆网（SR）中的转移。用1% Triton X-100从SR膜中溶出的酶进行了纯化和表征。胰蛋白酶也以活性形式溶解移植物。胰蛋白酶溶酶的性质包括分子大小与triton溶酶相似。这些结果表明，只有一部分转移可能插入到SR膜中。对鸡体内转移分布的研究表明，外周多形核细胞（嗜异核细胞）的特异性活性最高。对该杂性酶的纯化和鉴定表明，其性质与肝酶基本相同，但与鸡肝酶和兔肝酶的性质不同。例如，激活肝酶的二硫苏糖醇抑制了SR酶。内源性移情的生理作用仍然不清楚，可能是因为对这种酶的受体蛋白知之甚少。我们对它们进行了识别和表征；兔骨骼肌SR中的Ca^<2+> - atp酶和鸡肝脏中的33 kDa蛋白（p33）。鸡嗜异性粒细胞也含有高水平的p33。SR转移没有修饰p33，肝酶也没有adp -核糖化atp酶。这些结果表明，物种、组织和细胞特异性adp -核糖基转移酶更倾向于自己的靶蛋白进行原位adp -核糖基化。

Arginine-specific mono (ADP-ribosyl) transference in rabbit skeletal muscle sarcoplasmic reticulum (SR) was investigated. The enzyme solubilized with 1% Triton X-100 from the SR membranes was purified and characterized. Trypsin also solubilized the transference as active form. The properties including the molecular sizes of the trypsin-solubilized enzyme resemble those of the Triton-solubilized enzyme. These results indicate that just one part of the transference may be inserted in the SR membrane.Studies on distribution of the transference in chickens showed the highest specific activity in peripheral polymorphonuclear cells (heterophils). Purification and characterization of the heterophil enzyme revealed that the properties were indistinguishable from those of the liver enzyme, but those were different between chicken liver and rabbit SR enzymes. For example, dithiothreitol, which activate the liver enzyme, inhibited the SR enzyme. The physiological role of endogenous transference remains obscure, presumably because much less is known of acceptor proteins for the enzyme. We identified and characterized them ; Ca^<2+> -ATPase in rabbit skeletal muscle SR and 33 kDa protein (p33) in chicken liver. Chicken heterophils also contained high levels of p33. The SR transference did not modify the p33 and the liver enzyme did not ADP-ribosylate the ATPase. These results suggest that species, tissue and cell-specific ADP-ribosyltransferases prefer their own target proteins for the in situ ADP-ribosylation.