Research

SV-IV Peptide1–16 reduces coagulant power in normal Factor V and Factor V Leiden

Biagio Di Micco¹ , Marilena Lepretti² , Lidia Rota³ , Ilaria Quaglia³ , Paola Ferrazzi³ , Gianluca Di Micco² and Pierpaolo Di Micco^4,5

¹  University of Sannio Benevento Italy

²  Department of Biochemistry and Biophysics, Second University of Naples, Italy

³  Thrombosis Center, Istituto Clinico Humanitas, Milan, Italy

⁴  Department of Internal Medicine, Buon Consiglio Fatebenefratelli Hospital of Naples, Italy

⁵  Department of Biochemistry and Biotechnology and CEINGE, "Federico II" University of Naples, Italy

author email corresponding author email

Journal of Translational Medicine 2007, 5:69doi:10.1186/1479-5876-5-69

Published:	21 December 2007

Abstract

Native Factor V is an anticoagulant, but when activated by thrombin, Factor X or platelet proteases, it becomes a procoagulant. Due to these double properties, Factor V plays a crucial role in the regulation of coagulation/anticoagulation balance.

Factor V Leiden (FVL) disorder may lead to thrombophilia. Whether a reduction in the activation of Factor V or Factor V Leiden may correct the disposition to thrombophilia is unknown. Therefore we tested SV-IV Peptide 1–16 (i.e. a peptide derived by seminal protein vescicle number IV, SV-IV) to assess its capacity to inhibit the procoagulant activity of normal clotting factor V or Factor V Leiden (FVL). We found that SV-IV protein has potent anti-inflammatory and immunomodulatory properties and also exerts procoagulant activity. In the present work we show that the SV-IV Peptide 1–16, incubated with plasma containing normal Factor V or FVL plasma for 5 minutes reduces the procoagulant capacity of both substances. This is an anticoagulant effect whereas SV-IV protein is a procoagulant. This activity is effective both in terms of the coagulation tests, where coagulation times are increased, and in terms of biochemical tests conducted with purified molecules, where Factor X activation is reduced.

Peptide 1–16 was, in the pure molecule system, first incubated for 5 minutes with purified Factor V then it was added to the mix of phosphatidylserine, Ca2⁺, Factor X and its chromogenic molecule Chromozym X. We observed a more than 50% reduction in lysis of chromogenic molecule Chromozym X by Factor Xa, compared to the sample without Peptide 1–16. Such reduction in Chromozym X lysis, is explained with the reduced activation of Factor X by partial inactivation of Factor V by Peptide 1–16. Thus our study demonstrates that Peptide 1–16 reduces the coagulation capacity of Factor V and Factor V Leiden in vitro, and, in turn, causes factor X reduced activation.