Ciechanover A, Heller H, Elias S, Haas A L, Hershko A
Proc Natl Acad Sci U S A. 1980 Mar;77(3):1365-8. doi: 10.1073/pnas.77.3.1365.
The heat-stable polypeptide (APF-1) required for ATP-dependent proteolysis in reticulocytes enters into high molecular weight conjugates upon incubation with the fraction of reticulocytes that is retained by DEAE-cellulose. Conjugate formation requires ATP and Mg2+ and its inhibited by N-ethylmaleimide. UTP and GTP are inactive. These properties are identical to those of ATP-dependent protein breakdown in the same system, suggesting that the conjugates are intermediates in this process. The APF-1 conjugates are stable in sodium dodecyl sulfate/polyacrylamide gel electrophoresis and Sephadex G-75 isolation and are resistant to mild acid, alkali, heat denaturation, and reduction; the conjugates are therefore covalent.
网织红细胞中依赖ATP的蛋白水解所必需的热稳定多肽（APF-1），在与被DEAE-纤维素保留的网织红细胞部分一起孵育时，会形成高分子量的缀合物。缀合物的形成需要ATP和Mg2+，并受到N-乙基马来酰亚胺的抑制。UTP和GTP无活性。这些特性与同一系统中依赖ATP的蛋白质分解的特性相同，表明缀合物是这一过程的中间体。APF-1缀合物在十二烷基硫酸钠/聚丙烯酰胺凝胶电泳和Sephadex G-75分离中稳定，并且对弱酸、碱、热变性和还原具有抗性；因此，这些缀合物是共价的。
