Human Kallikrein 3/PSA

Prostate-specific antigen (PSA), also known as gamma-seminoprotein or kallikrein-3 (KLK3), P-30 antigen, is a glycoprotein enzyme encoded in humans by the KLK3 gene. PSA is a member of the kallikrein-related peptidase family and is secreted by the epithelial cells of the prostate gland in men and the paraurethral glands as an inactive enzyme (proPSA), a 28 kDa protein with 244 amino acides.The concentration ranges from 0.5-2.0 mg/ml in seminal plasma. It becomes activated with chymotrypsin-like enzymatic activity after 7 amino acids from the N-terminus removed. Then the major function of this active PSA is to cleave the gel-forming proteins in semen, seminogelin I, and seminogelin II, leading to liquefaction of semen clogs after ejaculation. Besides, PSA has also been found in other tissues or biological fluids, such as breast, urine and saliva with lower concentration.
There is about 70-90% of PSA circulating in serum complexes with others, such as ACT/serpin A1 or A3. The remaining 10-30% exists as unbound inactive enzyme (free PSA). When measured with available immunoassays, only free PSA and PSA-ACT are detectable and, traditionally, their sum is termed total PSA. If prostatic tissue damage occurs, such as in prostate cancer and benign hyperplasia, excess amounts of PSA will leak into the circulation, resulting in increased serum total PSA levels. Ratios between total and free PSA are frequently found to be lower in prostate cancer than benign hyperplasia. Due to the expression of PSA regulated by androgen, the determination of PSA levels in various biological fluids and cell culture supernates has thus been used to indicate the integrity of the androgen receptor signaling pathway.

Human Kallikrein 3/PSA

Monoclonal Antibody

Recombinant Protein

Kit for Human Sample