Kerbiriou D M, Griffin J H
J Biol Chem. 1979 Dec 10;254(23):12020-7.
Human high Mr kininogen was purified from normal plasma in 35% yield. The purified high Mr kininogen appeared homogeneous on polyacrylamide gels in the presence of sodium dodecyl sulfate and mercaptoethanol and gave a single protein band with an apparent Mr = 110,000. Using sedimentation equilibrium techniques, the observed Mr was 108,000 +/- 2,000. Human plasma kallikrein cleaves high Mr kininogen to liberate kinin and give a kinin-free, two-chain, disulfide-linked molecule containing a heavy chain of apparent Mr = 65,000 and a light chain of apparent Mr = 44,000. The light chain is histidine-rich and exhibits a high affinity for negatively charged materials. The isolated alkylated light chain quantitatively retains the procoagulant activity of the single-chain parent molecule. 125I-Human high Mr kininogen undergoes cleavage in plasma during contact activation initiated by addition of kaolin. This cleavage, which liberates kinin and gives a two-chain, disulfide-linked molecule, is dependent upon the presence of prekallikrein and Factor XII (Hageman factor) in plasma. Addition of purified plasma kallikrein to normal plasma or to plasmas deficient in prekallikrein or Factor XII in the presence or absence of kaolin results in cleavage of high Mr kininogen and kinin formation.
人高分子量激肽原从正常血浆中纯化得到，产率为35%。纯化后的高分子量激肽原在十二烷基硫酸钠和巯基乙醇存在的情况下，在聚丙烯酰胺凝胶上呈现均一性，给出一条表观分子量为110,000的单一蛋白条带。使用沉降平衡技术，观察到的分子量为108,000±2,000。人血浆激肽释放酶裂解高分子量激肽原以释放激肽，并产生一个不含激肽的、由二硫键连接的双链分子，该分子包含一条表观分子量为65,000的重链和一条表观分子量为44,000的轻链。轻链富含组氨酸，对带负电荷的物质表现出高亲和力。分离得到的烷基化轻链定量保留了单链亲本分子的促凝活性。125I-人高分子量激肽原在加入高岭土引发的接触激活过程中在血浆中发生裂解。这种裂解释放激肽并产生一个由二硫键连接的双链分子，其依赖于血浆中前激肽释放酶和因子Ⅻ（哈格曼因子）的存在。在有或没有高岭土存在的情况下，向正常血浆或缺乏前激肽释放酶或因子Ⅻ的血浆中加入纯化的血浆激肽释放酶会导致高分子量激肽原的裂解和激肽的形成。
