Kexin is a prohormone processing protease found in the budding yeast ( S. cerevisiae). It catalyses the cleavage of -Lys-Arg- and -Arg-Arg- bonds to process yeast alpha-factor pheromone and killer toxin precursors. The enzyme is encoded by the yeast gene KEX2, and usually referred to in the scientific community as Kex2p. It shares structural similarities with the bacterial protease subtilisin. The first mammalian homologue of this protein to be identified was furin.
The enzyme is also known as yeast KEX2 protease, proteinase yscF, prohormone-processing endoprotease, paired-basic endopeptidase, yeast cysteine proteinase F, paired-basic endopeptidase, andrenorphin-Gly-generating enzyme, endoproteinase Kex2p, gene KEX2 dibasic proteinase, Kex 2p proteinase, Kex2 endopeptidase, Kex2 endoprotease, Kex2 endoproteinase, Kex2 protease, proteinase Kex2p, Kex2-like precursor protein processing endoprotease, prohormone-processing KEX2 proteinase, prohormone-processing proteinase, proprotein convertase, protease KEX2, Kex2 proteinase, and Kex2-like endoproteinase.