Inhibition of acrosin by protein C inhibitor and localization of protein C inhibitor to spermatozoa.

Protein C inhibitor (PCI) is synthesized by cells throughout the male reproductive tract and is present in high concentrations (220 micrograms/ml) in seminal plasma. Seminal plasma as well as the acrosome of spermatozoa are rich in possible target proteases for PCI. We analyzed the interaction of PCI with acrosin, a serine protease stored in its zymogen form in the acrosome of spermatozoa. Purified human PCI inhibited the amidolytic activity of purified boar acrosin with an apparent second-order rate constant of 3.7 x 10(4) M-1.s-1. Inhibition was paralleled by the degradation of PCI from its 57- to its 54-kDa form. Human PCI also inhibited the amidolytic activity of activated human sperm extracts and formed complexes with acrosin as determined by an enzyme-linked immunosorbent assay. Immunocytochemistry revealed that morphologically abnormal spermatozoa stained for PCI antigen, whereas morphologically normal spermatozoa were negative. In immunoelectron microscopy, PCI was exclusively localized in the immediate vicinity of disrupted acrosomal membranes of sperm heads. These data suggest that PCI might function as a scavenger of prematurely activated acrosin, thereby protecting intact surrounding cells and seminal plasma proteins from possible proteolytic damage.

[1]  D. Latchman,et al.  Human sperm–egg binding is inhibited by peptides corresponding to core region of an acrosomal serine protease inhibitor , 1993, Molecular reproduction and development.

[2]  B. Binder,et al.  Inhibition of tissue kallikrein by protein C inhibitor. Evidence for identity of protein C inhibitor with the kallikrein binding protein. , 1992, The Journal of biological chemistry.

[3]  H. Lilja,et al.  Protein C inhibitor in human body fluids. Seminal plasma is rich in inhibitor antigen deriving from cells throughout the male reproductive system. , 1992, The Journal of clinical investigation.

[4]  J. Gilabert,et al.  Functionally active protein C inhibitor/plasminogen activator inhibitor-3 (PCI/PAI-3) is secreted in seminal vesicles, occurs at high concentrations in human seminal plasma and complexes with prostate-specific antigen. , 1991, Thrombosis research.

[5]  W. Schleuning,et al.  Activation and subsequent degradation of proacrosin is mediated by zona pellucida glycoproteins, negatively charged polysaccharides, and DNA , 1991, Molecular reproduction and development.

[6]  J. Griffin,et al.  Urinary protein C inhibitor. Glycosaminoclycans synthesized by the epithelial kidney cell line TCL-598 enhance its interaction with urokinase. , 1991, The Journal of biological chemistry.

[7]  J. Calvete,et al.  Variability of acrosin inhibitors in boar reproductive tract. , 1991, Biomedica biochimica acta.

[8]  R. Paulson,et al.  The influence of human follicular fluid on the acrosome reaction, fertilizing capacity and proteinase activity of human spermatozoa. , 1990, Human reproduction.

[9]  J. Nishioka,et al.  Protein C Inhibitor: Structure and Function , 1989, Thrombosis and Haemostasis.

[10]  M. Geiger.  Protein C inhibitor/plasminogen activator inhibitor 3 , 1988 .

[11]  J. Hedrick,et al.  The inhibition of boar acrosin amidase activity by sulfated polysaccharides. , 1988, Biological chemistry Hoppe-Seyler.

[12]  H. Van Erp,et al.  Inactivation of human plasma kallikrein and factor XIa by protein C inhibitor. , 1988, Biochemistry.

[13]  N Sakuragawa,et al.  Specificity of sulfated polysaccharides to accelerate the inhibition of activated protein C by protein C inhibitor. , 1987, Thrombosis research.

[14]  K. Kurachi,et al.  Characterization of a cDNA for human protein C inhibitor. A new member of the plasma serine protease inhibitor superfamily. , 1987, The Journal of biological chemistry.

[15]  B. Lämmle,et al.  Quantitative immunoblotting assay of blood coagulation factor XII. , 1986, Thrombosis research.

[16]  J. Hedrick,et al.  Proteolysis of the zona pellucida by acrosin: the nature of the hydrolysis products. , 1985, The Journal of experimental zoology.

[17]  J. Nishioka,et al.  Mechanism of inhibition of activated protein C by protein C inhibitor. , 1984, Journal of biochemistry.

[18]  L. Zaneveld,et al.  Inhibition of in-vitro fertilization of mouse gametes by proteinase inhibitors. , 1982, Journal of reproduction and fertility.

[19]  R. Marlar,et al.  Deficiency of protein C inhibitor in combined factor V/VIII deficiency disease. , 1980, The Journal of clinical investigation.

[20]  K. Robbins,et al.  Kinetics of activation of human plasminogen by different activator species at pH 7.4 and 37 degrees C. , 1980, The Journal of biological chemistry.

[21]  S. Mukerji,et al.  Proacrosin from rabbit epididymal spermatozoa: partial purification and initial biochemical characterization. , 1975, Biology of reproduction.

[22]  W. Schleuning,et al.  Some Characteristics of Highly Purified Boar Sperm Acrosin , 2009, Hoppe-Seyler's Zeitschrift fur physiologische Chemie.

[23]  P. Nakane,et al.  PEROXIDASE-LABELED ANTIBODY A NEW METHOD OF CONJUGATION , 1974, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[24]  L. Zaneveld,et al.  Inhibition of fertilization in vivo by pancreatic and seminal plasma trypsin inhibitors. , 1971, Journal of reproduction and fertility.

[25]  A. Neuberger,et al.  Tamm-Horsfall urinary glycoprotein. The chemical composition. , 1970, The Biochemical journal.

[26]  U. K. Laemmli,et al.  Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 , 1970, Nature.