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Characterization of PC2, a mammalian Kex2 homologue, following expression of the cDNA in microinjected Xenopus oocytes
Author(s) -
Shennan Kathleen I.J.,
Smeekens Steven P.,
Steiner Donald F.,
Docherty Kevin
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)80703-6
Subject(s) - xenopus , complementary dna , microbiology and biotechnology , biochemistry , messenger rna , biology , furin , prohormone convertase , serine proteinase inhibitors , subtilisin , chemistry , enzyme , prohormone , serine protease , gene , protease , hormone
A human insulinoma cDNA (PC2) that encodes a protein homologous to the Kex2/subtilisin‐like proteinases has recently been described [1990, J. Biol. Chem. 265, 2997–3000]. In order to characterise the associated proteinase activity, mRNA encoding PC2 was synthesised in vitro and micro‐injected into Xenopus oocytes. The proteinase activity released into the media from oocytes microinjected with PC2 mRNA was assayed using small peptide fluorogenic substrates. Boc.Gln.Arg.Arg aminomethyl coumarin was hydrolysed in a Ca 2+ ‐dependent manner, but substrate analogues bearing a single basic aminoacid were not. The substrate specificity, inhibitor profile, and pH optimum of 5.5 were compatible with an involvement of PC2 in prohormone processing in mammalian cells.