Pluthero F G, Shreeve M, Eskinazi D, van der Gaag H, Huang K S, Hulmes J D, Blum M, Axelrad A A
Department of Anatomy, University of Toronto, Ontario, Canada.
J Cell Biol. 1990 Sep;111(3):1217-23. doi: 10.1083/jcb.111.3.1217.
We have isolated a protein from media conditioned by a murine marrow-derived cell line (PB6) and from mouse marrow supernatants that antagonizes interleukin 3-dependent proliferation of cells in culture and reversibly inhibits DNA synthesis of erythroid progenitor cells (BFU-E) in vitro. This protein, p16 (monomer Mr = 16 kD on SDS-PAGE), was purified to homogeneity and amino acid sequencing of a polypeptide fragment yielded a sequence identical to that of murine cytosolic Cu,Zn-containing superoxide dismutase (SOD). The identification of p16 as SOD was confirmed by the detection of SOD enzymatic activity in pure p16 fractions, and when a commercial human erythrocytic SOD preparation was tested it showed the same cell inhibitory activities as p16. These observations show that superoxide dismutase is able to affect the cycling and growth factor responses of hematopoietic cells, activities that have not previously been associated with this enzyme.
我们从鼠骨髓衍生细胞系（PB6）条件培养基以及小鼠骨髓上清液中分离出一种蛋白质，它能在培养中拮抗白细胞介素3依赖的细胞增殖，并在体外可逆地抑制红系祖细胞（BFU-E）的DNA合成。这种蛋白质，p16（SDS-PAGE上单体Mr = 16 kD），被纯化至同质，对一个多肽片段进行氨基酸测序得到的序列与鼠胞质含铜、锌超氧化物歧化酶（SOD）的序列相同。通过在纯p16组分中检测到SOD酶活性，证实了p16就是SOD，并且当测试一种市售人红细胞SOD制剂时，它表现出与p16相同的细胞抑制活性。这些观察结果表明，超氧化物歧化酶能够影响造血细胞的周期和生长因子反应，而这些活性以前并未与该酶相关联。
