Cloning and characterization of mouse Klk27, a novel tissue kallikrein expressed in testicular Leydig cells and exhibiting chymotrypsin-like specificity

A cDNA clone of a new mouse tissue kallikrein, designated mKlk27, was isola ted from an adult mouse testis cDNA library. mKlk27 was expressed in the su bmaxillary glands and testis of the mouse. In testis, mKlk27 gene was expre ssed exclusively in the Leydig cells of the adult mouse. Active recombinant mKlk27 exhibited chymotrypsin-like cleavage specificity. A single amino-ac id substitution of Gly for Asp at position 209 in mKlk27 resulted in comple te loss of its chymotryptic activity but acquisition of tryptic activity. m Klk27 effectively hydrolyzed casein, gelatin and fibronectin. Insulin-like growth factor binding protein-3 was also hydrolyzed by recombinant mKlk27. These results suggest that mKlk27 plays an important role in association wi th the function of the adult mouse testis.