Pepinsky R B, Tizard R, Mattaliano R J, Sinclair L K, Miller G T, Browning J L, Chow E P, Burne C, Huang K S, Pratt D
Biogen Research Corporation, Cambridge, Massachusetts 02142.
J Biol Chem. 1988 Aug 5;263(22):10799-811.
We have purified two 35-kDa proteins from rat peritoneal lavages that inhibit phospholipase A2 activity. Both are calcium/phospholipid-dependent membrane binding proteins and share similar structural and biochemical properties with lipocortins I and II. By sequence analysis we confirmed that they are lipocortin-related, and we refer to the two inhibitors as lipocortins III and V. Using partial sequence information obtained from the purified rat proteins, full length cDNA clones for both proteins and for their human counterparts were isolated. As with lipocortins I and II, the amino acid sequences of lipocortins III and V which were deduced from the cDNA clones are highly conserved, sharing 50% identity with other family members. Related proteins were also purified from bovine intestinal mucosa and characterized by peptide mapping, sequence, and immunological analyses. In addition to lipocortins III and V the bovine preparation contained a third 35-kDa inhibitor and a 68-kDa inhibitor, extending the number of known lipocortins to six distinct proteins. While the various lipocortins are structurally similar, distinct differences in their cellular distribution indicate specialized roles for the individual proteins.
我们从大鼠腹腔灌洗液中纯化出了两种抑制磷脂酶A2活性的35 kDa蛋白。二者均为钙/磷脂依赖性膜结合蛋白，且与脂皮质素I和II具有相似的结构和生化特性。通过序列分析，我们证实它们与脂皮质素相关，因此将这两种抑制剂分别称为脂皮质素III和V。利用从纯化的大鼠蛋白中获得的部分序列信息，分离出了这两种蛋白及其人类对应物的全长cDNA克隆。与脂皮质素I和II一样，从cDNA克隆推导得到的脂皮质素III和V的氨基酸序列高度保守，与其他家族成员具有50%的同一性。还从牛小肠黏膜中纯化出了相关蛋白，并通过肽图谱分析、序列分析和免疫分析进行了表征。除脂皮质素III和V外，牛源制剂还含有第三种35 kDa抑制剂和一种68 kDa抑制剂，使已知脂皮质素的数量增加到六种不同的蛋白。虽然各种脂皮质素在结构上相似，但它们在细胞分布上的明显差异表明各蛋白具有特定的作用。
