Medved L V, Platonova T N, Litvinovich S V, Lukinova N I
Institute of Biochemistry, Academy of Sciences of the Ukrainian SSR, Kiev, USSR.
FEBS Lett. 1988 May 9;232(1):56-60. doi: 10.1016/0014-5793(88)80385-5.
It is shown that in the presence of Ca2+ plasmin converts bovine fibrinogen fragment DH (95 kDa) into DLA fragment by the cleavage of its beta-chain Arg372-Thr373 bond. DLA fragment consists of two components (82 and 12 kDa) held together by non-covalent bonds and has 3.5-fold higher anticlotting activity than DH fragment. The DH to DLA fragment conversion leads to the destabilization of thermolabile domains of the latter without the loss of their compact structure. The results obtained show that the activation of DH fragment by the cleavage of its Arg372-Thr373 bond bears some resemblance to the general activation of proenzyme into enzyme.
结果表明，在钙离子存在的情况下，纤溶酶通过切割牛纤维蛋白原片段DH（95 kDa）的β链Arg372 - Thr373键，将其转化为DLA片段。DLA片段由通过非共价键结合在一起的两个组分（82 kDa和12 kDa）组成，其抗凝血活性比DH片段高3.5倍。从DH片段到DLA片段的转化导致后者热不稳定结构域的不稳定，但不损失其紧密结构。所得结果表明，通过切割其Arg372 - Thr373键对DH片段的激活与将酶原普遍激活为酶有一些相似之处。
