Mertens K, Bertina R M
Biochem J. 1980 Mar 1;185(3):647-58. doi: 10.1042/bj1850647.
Purified human Factor X (apparent mol.wt. 72000), which consists of two polypeptide chains (mol.wt. 55000 and 19000), was activated by both Russell's-viper venom and the purified physiological activators (Factor VII/tissue factor and Factor IXa/Factor VIII). They all convert Factor X to catalytically active Factor Xa (mol.wt. 54000) by cleaving the heavy chain at a site on the N-terminal region. In the presence of Ca2+ and phospholipid, the Factor Xa formed catalyses (a) the cleavage of a small peptide (mol.wt. 4000) from the C-terminal region of the heavy chain of Factor Xa, resulting in a second active form (mol.wt. 50000), and (b) the cleavage of a peptide containing the active-site serine residue (mol.wt. 13000) from the C-terminal region of the heavy chain of Factor X, resulting in an inactivatable component (mol.wt. 59000). A nomenclature for the various products is proposed.
纯化的人凝血因子X（表观分子量72000）由两条多肽链（分子量分别为55000和19000）组成，它可被罗素蝰蛇毒以及纯化的生理性激活剂（凝血因子VII/组织因子和凝血因子IXa/凝血因子VIII）激活。它们均通过在重链N端区域的一个位点进行切割，将凝血因子X转化为具有催化活性的凝血因子Xa（分子量54000）。在钙离子和磷脂存在的情况下，形成的凝血因子Xa催化：(a) 从凝血因子Xa重链的C端区域切割出一个小肽（分子量4000），产生第二种活性形式（分子量50000）；(b) 从凝血因子X重链的C端区域切割出一个含有活性位点丝氨酸残基的肽（分子量13000），产生一种可失活的成分（分子量59000）。本文提出了各种产物的命名法。
