Exp Mol Med.  2002 Nov;34(5):385-390.

Effects of Val34Leu and Val35Leu polymorphism on the enzyme activity of the coagulation factor XIII-A

• Lee IH
• Chung SI
• Lee SY

Abstract

Change in fibrin stabilizing activity of factor XIII A subunit (FXIII-A) caused by a specific mutation, Val34Leu, is recently implicated to incidences of pathophysiology of thrombosis. In an effort to understand the effect of Val34Leu on enhanced catalytic role of FXIII-A, wild type human factor XIII A (HFXIII-A) and mutant HFXIII-A: HFXIII-A (V34L), HFXIII-A (V35L) and HFXIII-A (V34L/V35L) cDNA were expressed in E.coli system where the purified recombinant FXIII-A (rFXIII-A) showed a similar specific transglutaminase activity comparable to the human native FXIII-A from platelet. Using these rFXIII-A mutants, the activation kinetics by thrombin and the enzymatic properties of the activated rFXIII-A were characterized. rFXIII-A (V34L) and rFXIII-A (V34L/V35L) mutants were activated by thrombin much faster than those of wild type rFXIII-A and V35L variant. However, the activated rFXIII-A and mutants showed the identical catalytic efficiency as measured by in vitro assay. These results suggest that ready activation caused by a specific mutation of neighboring thrombin cleavage site(s) in the activation peptide of FXIII-A like V34L resulted in the real-time amount of the activated factor XIII-A that could influence the outcome of fibrin stabilization in vivo such as alpha2- plasmin inhibitor crosslinking to fibrin, a reaction known to be dependent on the initial concentration of active factor-XIII-A.

Keyword

Factor XIII; Val34Leu; Val35Leu; catalytic efficiency; site-directed mutagensis

MeSH Terms

Blood Coagulation Tests
Catalysis
Enzyme Activation/genetics
Escherichia coli/genetics
Factor XIII/*genetics/*metabolism
Fibrin/metabolism
Human
Immunoblotting
Leucine/genetics
Mutagenesis, Site-Directed
*Polymorphism (Genetics)
Recombinant Proteins/genetics/metabolism
Thrombin/metabolism
Valine/genetics