Human tissue kallikreins are a family of 15 trypsin or chymotrypsin-like secreted serine proteases (hK1-hK15). hK5, hK6, hK7, hK8, and hK13 have been identified in the stratum corneum (SC), stratum granulosum, and skin appendages. It has been reported that hK5 and hK7 degrade desmosomes/corneodesmosomes, suggesting that kallikreins are responsible for desquamation. We report the quantification of hK5, hK6, hK7, hK8, hK10, hK11, hK13, and hK14 in the SC by ELISA and their variation among age groups. The total SC trypsin and chymotrypsin-like activities were also measured. The amount of hK7, hK8, and hK11 (ng per mg dry weight) were high, and varied from 6 to 14, hK5 (2.0-4.0) was present at intermediate levels, and hK10 (0.65-1.0), hK14 (0.1-0.3), hK6 (0.1-0.3), and hK13 (0.02-0.1) were present at lower levels. hK6 and hK14 were significantly lower in females between 20 and 59 y. hK5, hK7, hK10, hK11, and hK14 were not significantly different across the age groups. hK8 was lowest at extremes of age (highest at 30-39 y), hK6 was lower at >30 y, and hK13 was lower at >20 y. Overall trypsin-like activity did not differ across age groups but was higher in subjects <11 y. Overall chymotrypsin-like activity was not related to age. In conclusion, we found multiple kallikreins in the SC and suggest that these enzymes may be responsible for desquamation through an enzymatic cascade pathway.

No abstract

Kallikrein gene families have been identified previously in genomes of the human, the mouse, and the rat, and individual kallikrein-like genes have been found in many more species. This study presents the in silico identification of kallikrein gene families in the recently sequenced genomes of four additional mammalian species, the chimpanzee, the dog, the pig, and the opossum. Phylogenies were constructed with gene sequences from all seven mammalian families, using Bayesian analysis, which clarified the evolutionary relationships between these genes. Individual gene sequences, as well as concatenated constructs of multiple sequences, were used. Fifteen kallikrein genes were located in the chimpanzee (Pan troglodytes) genome, while only 14 were identified in the canine (Canis familiaris) genome as no orthologue to human KLK3 was found. Thirteen genes were identified from the pig (Sus scrofa) genome, which lacked homologues to KLK2 and KLK3, and 11 genes, orthologous to human KLK5 through KLK15, were found in the opossum (Monodelphis domestica) genome. No kallikrein genes were identified from the available genome sequences of the chicken (Gallus gallus) or African clawed frog (Xenopus tropicalis). Within the family of kallikreins several subfamilies were suggested by phylogenetic analysis. One consisted of KLK4, KLK5, and KLK14; another of KLK9, KLK11, and KLK15; a third of KLK10 and KLK12; a fourth of KLK6 and KLK13; and finally one of KLK8 and the classical kallikreins (KLK1, KLK2, and KLK3).

No abstract

No abstract

No abstract

Purpose: Preliminary data suggest that hK11 is a novel serum biomarker for prostate and ovarian cancer. To examine the enzymatic characteristics of hK11, we purified and functionally characterized native hK11from seminal plasma. Experimental Design: hK11was purified from seminal plasma by immunoaffinity chromatography and characterized by kinetic analysis, electrophoresis,Western blots, and mass spectrometry.Results: hK11is present in seminal plasma at concentrations ranging from 2 to 37 Ag/mL. Using immunoaffinity chromatography and reverse-phase high-performance liquid chromatography, we purified hK11 to homogeneity. In seminal plasma, hK11 is present as a free enzyme of f40 kDa. About 40% of hK11 is enzymatically active, whereas the rest is inactivated by internal cleavage after Arg 156 (Genbank accession no. AF164623), which generates two peptides of f20 kDa, connected by internal disulfide bonds. Purified hK11 possesses trypsin-like activity and cleaves synthetic peptides after arginine but not lysine residues. It does not cleave chymotrypsin substrates. Antithrombin, a 1 -antichymotrypsin, a 2 -antiplasmin, and a 1 -antitrypsin have no effect on hK11 activity and do not form complexes with hK11 in vitro. The strongest inhibitor, APMSF, completely inhibited hK11 activity at a concentration of 2.5 mmol/L. Aprotinin and an hK11-specific monoclonal antibody inhibited hK11activity up to 40%. Plasmin is a strong candidate for cleaving hK11at Arg .Conclusion: This is the first report on purification and characterization of native hK11. We speculate that hK11, along with other kallikreins, proteases, and inhibitors, participates in a cascade enzymatic pathway responsible for semen liquefaction after ejaculation.

No abstract