Kallikreins are serine protease enzymes having various physiological functions.
Kallikreins are implicated in carcinogenesis and have potenital as novel cancer disease biomarkers. KLK1 is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. KLK1 is functionally conserved in its ability to release the vasoactive peptide， Lys-bradykinin， from low molecular weight kininogen.
Human Kallikrein-1， also called as Kallidinogenase， Kininogenase or Kininogenin， is an active protein enzyme present in saliva， pancreatic juices， and urine that catalyzes the proteolysis of bradykininogen to bradykinin.
Kallikrein-1， which derived from human or porcine， have been used as drugs for a long time， they are mainly used in the treatment f light to medium hypertension and occlusion of cerebral and surrounding blood vessels.
KLK1 demonstrates both trypsin- and chymotrypsin-like selectivities with Tyr/Arg preferred at site P1， Ser/Arg strongly preferred at P1’， and Phe/Leu at P2.
rs5517 in the KLK1 gene is considerably connected with hypertension in a Chinese Han population. KLK1 is expressed de novo in endothelial cells and mediates relaxation of human umbilical veins. The K allele of KLK1 promoter and TT genotype of TGF-beta1 are a genetic KLK1 -130 GN and -128 G-C， and the defenselessness factor contributing to progressive renal descent in Taiwanese primary vesicoureteric reflux children.
Induction of KLK1 in carotid arteriosclerosis doesn’t lead to kallikrein-kinins pathway activation. Transgenic rats expressing KLK1 have impaired renal response to acute volume expansion Endothelial cells synthesize and release active form of KLK1on the surface which is important function in maintenance of circulation homeostasis.
KLK1 participates in epidermal desquamation through cleavage of desmoglein 1 and regulation by lympho-epithelial Kazal-type-related inhibitor（LEKTI).
