Martin B M, Quigley J P
J Cell Physiol. 1978 Aug;96(2):155-64. doi: 10.1002/jcp.1040960204.
Human alpha thrombin acts as a mitogen for cultures of resting chick embryo fibroblasts (CEF) in serum free medium. The use of 125I-labeled thrombin shows that thrombin specifically binds to CEF and that after a lag of approximately 30 to 60 minutes it can not be removed by subsequent exposure to trypsin. The entry of 125I thrombin into the trypsin-insensitive domain is not inhibited to any great extent by excess unlabelled thrombin. The cell-associated thrombin retains its native molecular weight and its catalytic activity toward synthetic amide substrates. It appears to be located in the crude nuclear fraction of homogenized CEF cells. The association of thrombin with CEF is specific, since the non-mitogenic serine protease chymotrypsin is internalized to a much lesser extent than thrombin. The data are discussed in terms of a possible intracellular site for thrombin's mitogenic action.
人α-凝血酶在无血清培养基中可作为静止鸡胚成纤维细胞（CEF）培养的促有丝分裂原。使用125I标记的凝血酶表明，凝血酶能特异性结合CEF，且在大约30至60分钟的延迟后，随后用胰蛋白酶处理不能将其去除。过量未标记的凝血酶对125I凝血酶进入胰蛋白酶不敏感区域的抑制作用不大。与细胞结合的凝血酶保留其天然分子量及其对合成酰胺底物的催化活性。它似乎位于匀浆CEF细胞的粗核部分。凝血酶与CEF的结合具有特异性，因为无促有丝分裂作用的丝氨酸蛋白酶胰凝乳蛋白酶内化程度远低于凝血酶。文中根据凝血酶促有丝分裂作用可能的细胞内位点对数据进行了讨论。
