COMPARISON OF STRUCTURES OF VARIOUS HUMAN FIBRINOGENS AND A DERIVATIVE THEREOF BY A STUDY OF THE KINETICS OF RELEASE OF FIBRINOPEPTIDES
COMPARISON OF STRUCTURES OF VARIOUS HUMAN FIBRINOGENS AND A DERIVATIVE THEREOF BY A STUDY OF THE KINETICS OF RELEASE OF FIBRINOPEPTIDES
复制标题
DOI：
10.1021/bi00315a025
复制
发表时间：
1984-01-01
期刊：
影响因子：
2.9
通讯作者：
MARDER, VJ
中科院分区：
文献类型：
--
作者：
HANNA, LS;SCHERAGA, HA;MARDER, VJ
利用高效液相色谱技术分离反应产物，研究了凝血酶诱导的纤维蛋白肽从几种人纤维蛋白原变体及其溶酶酶解片段E中释放的动力学。根据Michaelis-Menten机制对数据进行分析，其中a.a。和B.beta。链争夺凝血酶。a - α的Ser-3磷酸化。链似乎增加了纤维蛋白原释放相应磷酸化肽A的速率，由于凝血酶的结合增强（Km值较低）。然而，磷酸化并不影响未磷酸化的A或B肽的释放速率。增加。gamma的长度。链（在c端）不影响任何纤维蛋白肽的释放速率。片段E（不含B肽）释放A肽的速率与完整纤维蛋白原分子的速率相似。这些结果与早先的结论一致，即a.a。和B.beta。链在争夺凝血酶时表现独立；即a.a α的可水解Arg-Gly键。和B.beta。凝血酶都能接触到这两条链。
The kinetics of the thrombin-induced release of fibrinopeptides from several variants of human fibrinogen, and from the plasmin digestion fragment E thereof, were studied by using an HPLC [high performance liquid chromatography] technique to separate the reaction products. The data were analyzed in terms of a Michaelis-Menten mechanism in which the A.alpha. and B.beta. chains compete for thrombin. Phosphorylation of Ser-3 of the A.alpha. chain appears to increase the rate of release of the corresponding phosphorylated peptide A from fibrinogen, due to enhanced binding of thrombin (lower value of the Km). However, phosphorylation does not affect the rate of release of the unphosphorylated A or B peptides. Increase in the length of the .gamma. chain (at the C-terminus) does not affect the rate of release of any of the fibrinopeptides. The rate of release of the A peptide from fragment E (which is devoid of the B peptide) is similar to that for the the complete fibrinogen molecule. These results are in agreement with an earlier conclusion that the A.alpha. and B.beta. chains behave independently in their competition for thrombin; i.e., the hydrolyzable Arg-Gly bonds of the A.alpha. and B.beta. chains are both accessible to thrombin.