Kallikrein

Description

Plasma kallikrein possesses a unique protein structure with four apple domains and a trypsin domain, which evolved before coagulation factor XI. Tissue kallikreins are trypsinbased enzymes, and some members are highly correlated with prostate cancer. The evidence that human urine induces hypotension when injected intravenously into anesthetized dogs was first described in 1909. Two major kallikreins, plasma kallikrein (KLKB1) and tissue (glandular) kallikrein (KLK), were found in mammals, and they were transcribed by different genes. Glandular KLK was an old name and was replaced by tissue KLK in the modern nomenclature.

The Uses of Kallikrein

Kallikrein from porcine pancreas has been used:

• as a matrix metalloproteinase-9 (MMP-9) zymogen activator
• as a component of cell culture to test its effect on rat subventricular zone (SVZ) cells and oligodendrocyte progenitor cells (OPC) proliferation and survival
• as a model enzyme to track kinetic data and visual detection limits of hydrolysis by hydrolytic enzymes in the two-phases array

General Description

Kallikrein exists as an inactive prokallikrein in the porcine pancreas. The porcine kallikrein gene region is localized on chromosome 6q12-q21.

Biochem/physiol Actions

Kallikrein active forms are generated by the enzymatic action of trypsin. It is a serine protease that mediates the activation of growth factors and substrates.

Clinical Use

Kallikreins are drug targets for the control of hypertension, inflammation, and blood coagulation diseases. They are also possible biomarkers for cancer. KLK2 and KLK3 [prostate-specific antigen (PSA)] are used as the serum biomarker for prostate cancer.