Harris J U, Johnson A J, Merskey C, Wang M T, Robinson D
Biochem J. 1979 Dec 1;183(3):623-32. doi: 10.1042/bj1830623.
Fibrinogen-fibrin-related antigen (FR antigen) was isolated from as little as 1 ml of human plasma by immuno-affinity chromatography with agarose-bound antibody to human fibrinogen. N-terminal analysis was performed to determine the nature and extent of proteolytic degradation of the FR antigen in patients with disseminated intravascular coagulation and in normal subjects. Thrombin cleavage of the A- and B-peptides from fibrinogen in vitro was monitored by the appearance of N-terminal glycine, and an increase in glycine was shown in the FR antigen of patients with disseminated intravascular coagulation. As plasmin progressively degraded fibrinogen, increases in N-terminal alanine, aspartic acid and lysine were observed, corresponding to the known plasmin-cleavage points of fibrinogen; increases in these N-terminal amino acids were also found in the patients' FR antigen. Thrombin treatment in vitro was used to remove fibrinopeptide A (N-terminal alanine) from the samples and to reflect specifically the N-terminal alanine at the plasmin-cleavage point (Arg-42-Ala-43) of the B beta-chain on assay; this alanine was increased progressively in the FR antigen of a patient during urokinase therapy, and was high in other patients when the FR antigen was examined by this procedure.
通过使用与琼脂糖结合的抗人纤维蛋白原抗体进行免疫亲和层析，从仅1毫升人血浆中分离出纤维蛋白原 - 纤维蛋白相关抗原（FR抗原）。对弥散性血管内凝血患者和正常受试者的FR抗原进行N端分析，以确定其蛋白水解降解的性质和程度。通过N端甘氨酸的出现监测体外凝血酶从纤维蛋白原上切割A肽和B肽的过程，结果显示弥散性血管内凝血患者的FR抗原中甘氨酸增加。随着纤溶酶逐渐降解纤维蛋白原，观察到N端丙氨酸、天冬氨酸和赖氨酸增加，这与已知的纤维蛋白原纤溶酶切割位点相对应；在患者的FR抗原中也发现了这些N端氨基酸的增加。体外凝血酶处理用于从样品中去除纤维蛋白肽A（N端丙氨酸），并在检测时特异性反映Bβ链纤溶酶切割位点（Arg-42-Ala-43）处的N端丙氨酸；在一名患者接受尿激酶治疗期间，其FR抗原中的这种丙氨酸逐渐增加，而当通过该方法检测其他患者的FR抗原时，该丙氨酸含量较高。
