Effects of Val34Leu and Val35Leu polymorphism on the enzyme activity of the coagulation factor XIII-A.
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 (gammaFXIII-A) showed a similar specific transglutaminase activity comparable to the human native FXIII-A from platelet. Using these gammaFXIII-A mutants, the activation kinetics by thrombin and the enzymatic properties of the activated gammaFXIII-A were characterized. gammaFXIII-A (V34L) and gammaFXIII-A (V34L/V35L) mutants were activated by thrombin much faster than those of wild type gammagFXIII-A and V35L variant. However, the activated gammaFXIII-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.
Lee
Il-Ha
IH
Department of Natural Sciences, Chemistry Section, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, Seoul 137-701, Korea.
Chung
Soo-Il
SI
Lee
Soo-Young
SY
D001780:Blood Coagulation Tests; D002384:Catalysis; D004789:Enzyme Activation / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005176:Factor XIII / Q000235:genetics* / Q000378:metabolism*; D005337:Fibrin / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007930:Leucine / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D011110:Polymorphism, Genetic; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013917:Thrombin / Q000378:metabolism; D014633:Valine / Q000235:genetics
D011994:Recombinant Proteins; D005337:Fibrin; D005176:Factor XIII; D013917:Thrombin; D007930:Leucine; D014633:Valine