seminal

Semenogelin-1 (SEMG1) is the predominant protein in semen; it is a secretory protein involved in the formation of a gel matrix entrapping the accessory gland secretions and ejaculated spermatozoa. The prostate-specific antigen (PSA) protease processes SEMG1 into smaller peptides, each possibly having a separate function. In the proteolysis process, Alpha-inhibin-92 and alpha-inhibin-31 are produced; they inhibit the secretion of pituitary follicle-stimulating hormone. At the same time, it breaks down the gel matrix, allowing the spermatozoa to move more freely.

SVS4 Protein, Mouse, Recombinant (His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 17.8 kDa and the accession number is P18419.

Serpin E2 is a member of the Serpin superfamily. It is differentially expressed during neuronal differentiation and is able to transform human embryonic kidney cells into neuronlike cells. Its over-expression in mice leads to progressive neuronal and motor dysfunction in these animals. It is also over-expressed in the majority of pancreatic carcinoma as well as gastric and colorectal cancer samples whereas it is weakly expressed in all normal pancreas and chronic pancreatitis tissue samples. Serpin E2 is a potent inhibitor of thrombin, trypsin, urokinase, plasmin and plasminogen activators. It plays an important role in controlling male fertility because its knockout male mice show a marked impairment in fertility from the onset of sexual maturity and its abnormal expression is found in the semen of men with seminal dysfunction.

Alpha-2-glycoprotein, also known as AZGP1, belongs to the MHC class I family. It can be detected in body fluids such as serum, sweat, and seminal and breast cyst fluids. It has been shown that alpha-2-glycoprotein can stimulate lipolysis by adipocytes in vivo and in vitro. Thus it is believed that alpha-2-glycoprotein plays an important role in the regulation of body weight, and age-dependent changes in genetically influenced obesity, and it also regulates melanin production by normal and malignant melanocytes. Alpha-2-glycoprotein is produced by both white and brown fat adipocytes and may act in a local autocrine fashion in the reduction of adiposity in cachexia.

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.

Cystatin-S, also known as Cystatin-4, Salivary acidic protein 1, Cystatin-SA-III and CST4, is a secreted protein which belongs to thecystatin family. Cystatin-4 CST4 is expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). It is also expressed in saliva, tears, urine and seminal fluid. The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions. Cystatin-4 CST4 strongly inhibits papain and ficin, partially inhibits stem bromelain and bovine cathepsin C, but does not inhibit porcine cathepsin B or clostripain. Papain is inhibited non-competitively. Cystatin-4 CST4 is an S-type cystatin, based on its high level of expression in saliva, tears and seminal plasma. The specific role in these fluids is unclear but antibacterial and antiviral activity is present, consistent with a protective function.

KLK3 (Kallikrein Related Peptidase 3) is a Protein Coding gene. The gene is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. It encodes a single-chain glycoprotein, a protease that is synthesized in the epithelial cells of the prostate gland and is present in seminal plasma. KLK3, also known as Prostate Specific Antigen (PSA), kallikrein-related peptidase 3, Gamma-seminoprotein, is a secreted protein of the glandular kallikrein subfamily of serine proteases. KLK3 contains one peptidase S1 domain. KLK3 is a glycoprotein produced almost exclusively by the prostate gland. Growing evidence suggests that many kallikreins are implicated in carcinogenesis and some have potential as novel cancer and other disease biomarkers.Cancer ImmunotherapyImmune CheckpointImmunotherapyTargeted Therapy

Serpin E2 is a secreted protein that belongs to the serpin family. Serpin E2 is a serine protease inhibitor with activity toward thrombin, trypsin, and urokinase. Serpin E2 expression is weak or absent in all normal pancreas and chronic pancreatitis tissue. In contrast, it was strongly over-expressed in the majority of pancreatic carcinoma as well as gastric and colorectal cancer samples. Serpin E2 promotes neurite extension by inhibiting thrombin. It also can bind heparin. It has been shown that Serpin E2 is a novel target of ERK signaling involved in human colorectal tumorigenesis. It plays an important role in controlling male fertility because its knockout male mice show a marked impairment in fertility from the onset of sexual maturity and its abnormal expression is found in the semen of men with seminal dysfunction.

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.

Cystatin-SN, also known as Cystain-SA-I, Cystatin-1, Salivary cystatin-SA-1 and CST1, is a secreted protein which belongs to thecystatin family. The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. Cystatin-SN CST1 is expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). Cystatin-SN CST1 is also expressed in saliva, tears, urine and seminal fluid. Human saliva appears to contain several cysteine proteinase inhibitors that are immunologically related to cystatin S but that differ in their specificity due to amino acid sequence differences. Human salivary cystatins include Cystatin-S, Cystatin-S1, Cystatin-S2, Cystatin- SA, Cystatin-SN, Cystatin-C and Cystatin-D. Cystatin-SN is a much better inhibitor of papain and dipeptidyl peptidase I than is cystatin-S, although both inhibit ficin equally well.