ADP-Ribosylation Reaction in Rabbit Skeletal Muscle SR

研究了精氨酸特异性单（ADP-核糖基）在兔骨骼肌肌浆网（SR）中的转运。用1%Triton X-100从SR膜溶解的酶被纯化和表征。胰蛋白酶也溶解了作为活性形式的转移。胰蛋白酶溶解的酶的性质，包括分子大小类似于那些的Triton溶解的酶。这些结果表明，只有一部分的转移可能是插入SR膜。转移在鸡的分布研究表明，在外周多形核细胞（heterophiles）的比活性最高。异嗜性酶的纯化和性质的研究表明，这些性质是不可区分的肝酶，但这些是不同的鸡肝和兔SR酶。例如，激活肝酶的二硫苏糖醇抑制SR酶。内源性转移的生理作用仍然模糊不清，大概是因为对这种酶的受体蛋白知之甚少。我们鉴定并鉴定了它们：兔骨骼肌SR中的Ca^<2+> -ATPase和鸡肝中的33 kDa蛋白（p33）。鸡嗜异性粒细胞也含有高水平的p33。SR转移不修饰p33，肝酶不使ATP酶发生ADP-核糖基化。这些结果表明，物种，组织和细胞特异性ADP-核糖基转移酶更喜欢自己的靶蛋白的原位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.