acrosin

Serine protease of trypsin-like cleavage specificity. Synthesized in a zymogen form, proacrosin and stored in the acrosome. Acrosin Protein, Meleagris gallopavo, Recombinant (His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 43.1 kDa and the accession number is Q2UVH8.

Human serine proteinase inhibitor Kazal-type 2 (SPINK2) functions as a trypsin acrosin inhibitor and is synthesized mainly in the testis and seminal vesicle where its activity is engaged in fertility. The SPINK2 protein contains a typical Kazal domain composed by six cysteine residues forming three disulfide bridges. The expression of SPINK2 is closely related to cancer such as lymphomas, in that a high transcript level of SPINK2 in patients with primary cutaneous follicle center cell lymphomas have better prognosis with lower mortality. SPINK2 is necessary to neutralize proteases during their cellular transit toward the acrosome and that its deficiency induces a pathological continuum ranging from oligoasthenoteratozoospermia in heterozygotes to azoospermia in homozygotes.

Serpin A5 is a member of the human Serpin superfamily consists of at least 35 members. It is synthesized in the liver and has been detected in saliva, cerebral spinal fluid, amniotic fluid, tears and semen. As a potent inhibitor of the protein C anticoagulant pathway at the levels of both zymogen activation and enzyme inhibition, Serpin A5 additionally inhibits a variety of serine protease including thrombin, factor Xa, several kallekreins and acrosin. It plays a critical role in the processes of blood of blood coagulation and fertilization. Serpin A5 also inhibits urinary plasminogen activator (uPA), a mediator of tumor cell invasion, and regulates tumor growth and metastasis by inhibiting angiogenesis. Furthermore, recent studies have identified PCI as a potent and direct inhibitor of activated HGFA (hepatocyte growth factor activator), suggesting a novel function in the regulation of tissue repair and regeneration. Similar to Serpins C1 and D1, the thrombin inhibitory activity of serpinA5 is enhanced by heparin.

As a strong inhibitor of acrosin, it is required for normal spermiogenesis. It probably hinders premature activation of proacrosin and other proteases, thus preventing the cascade of events leading to spermiogenesis defects. May be involved in the regulation of serine protease-dependent germ cell apoptosis. It also inhibits trypsin. SPINK2 Protein, Mouse, Recombinant (His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 15.0 kDa and the accession number is Q8BMY7.

Heparin-dependent serine protease inhibitor acting in body fluids and secretions. Inactivates serine proteases by binding irreversibly to their serine activation site. Involved in the regulation of intravascular and extravascular proteolytic activities. Plays hemostatic roles in the blood plasma. Acts as a procoagulant and proinflammatory factor by inhibiting the anticoagulant activated protein C factor as well as the generation of activated protein C factor by the thrombin thrombomodulin complex. Acts as an anticoagulant factor by inhibiting blood coagulation factors like prothrombin, factor XI, factor Xa, plasma kallikrein and fibrinolytic enzymes such as tissue- and urinary-type plasminogen activators. In seminal plasma, inactivates several serine proteases implicated in the reproductive system. Inhibits the serpin acrosin; indirectly protects component of the male genital tract from being degraded by excessive released acrosin. Inhibits tissue- and urinary-type plasminogen activator, prostate-specific antigen and kallikrein activities; has a control on the sperm motility and fertilization. Inhibits the activated protein C-catalyzed degradation of SEMG1 and SEMG2; regulates the degradation of semenogelin during the process of transfer of spermatozoa from the male reproductive tract into the female tract. In urine, inhibits urinary-type plasminogen activator and kallikrein activities. Inactivates membrane-anchored serine proteases activities such as MPRSS7 and TMPRSS11E. Inhibits urinary-type plasminogen activator-dependent tumor cell invasion and metastasis. May also play a non-inhibitory role in seminal plasma and urine as a hydrophobic hormone carrier by its binding to retinoic acid.