Human factor VIII, amino-acid sequences

The human factor V amino acid sequence deduced from the cDNA sequence (II) contains a signal sequence of 28 amino acids and the mature procofactor of 2196 amino acid residues. The amino acid sequence shows that factor V has a multidomainal structure that is similar to factor Vlll. The different domains can be defined as AI, between residues I-3I7 A2, from residues 318-663 B, from residues 664-1545 A3, from residues 1546-1883 Cl, from residues 1884-2036, and C2, from residues 2037-2196. As discussed previously, human factor V and factor VIII show 21 to 44% homology with ceruloplasmin in the A domains. 

About 40% (938 residues) of the amino-acid sequence of factor V has been established (103). It shows similarities to the amino-acid sequences of human ceruloplasmin and human factor VIII. The partial sequence contains a region that is similar to domains 5 and 6 in ceruloplasmin and A3 in factor VIII. However, it does not have the canonical ligands for type-1 copper or the trinuclear copper site. On the other hand, cysteine residues are present at the homologous position of ceruloplasmin. They form a disulfide bridge in this structure. 

The preparation and the assay of the components of fibrinolysis and thrombolysis have been reviewed." The amino-acid sequences at the NH2-terminus, molecular weights, and amino-acid compositions of human prothrombin, factors IX and X, and a new plasma protein have been compared." Desialylation of human plasma factor VIII decreased its ristocetin-induced platelet-aggregation activity and facilitated its clearance by hepatocytes, but its procoagulant activity was not affected." " Experiments in vivo have confirmed the view that the inhibi-... 

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