title: Biochemical characterization and substrate specificity of rat prostate kallikrein (S3): comparison with tissue kallikrein, tonin and T-kininogenase.
abstract: A tissue kallikrein-like enzyme encoded by S3 mRNA was purified to homogeneity from rat prostate gland. The apparent molecular mass of the prostate enzyme is 32 kDa as determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The intact 32 kDa enzyme is split into two bands of lower molecular mass, 18 and 14 kDa, under reducing conditions on SDS-PAGE. NH2-terminal amino acid sequence analyses of the intact enzyme and heavy and light chains revealed the identity to the translated sequence of a prostate kallikrein cDNA (S3). Isoelectric focusing indicated that the prostate enzyme is a basic protein with pI of 7.30-7.45. Specific activities of the prostate kallikrein toward angiotensin I, angiotensinogen and rat low M(r) kininogen as well as tripeptide chromogenic substrates were compared with those of tissue kallikrein, tonin and T-kininogenase. The kinin-releasing activity is inhibited by leupeptin, antipain, benzamidine and soybean trypsin inhibitor. A sensitive and specific radioimmunoassay for the rat prostate kallikrein shows that the immunoreactive kallikrein levels in prostate and submandibular gland were 23.78 +/- 2.62 micrograms/mg protein (n = 5) and 12.29 +/- 2.25 micrograms/mg protein (n = 5), respectively. The results indicate that the prostate kallikrein S3 is expressed at high levels in both prostate and submandibular glands.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston 29425.
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: C Q
authors.initials: CQ
authors.lastname: Tang
authors.forename: G X
authors.initials: GX
authors.lastname: Zhou
authors.forename: L
authors.initials: L
authors.lastname: Chao
authors.forename: J
authors.initials: J
authors.lastname: Chao
mesh_terms: D000595:Amino Acid Sequence; D000803:Angiotensin I / Q000378:metabolism; D000808:Angiotensinogen / Q000378:metabolism; D000818:Animals; D004247:DNA; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D007610:Kallikreins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007704:Kininogens / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000378:metabolism*; D011467:Prostate / Q000201:enzymology*; D012333:RNA, Messenger / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity; D014361:Trypsin Inhibitors / Q000494:pharmacology
chemical_list: D007704:Kininogens; D010455:Peptides; D012333:RNA, Messenger; D014361:Trypsin Inhibitors; D000808:Angiotensinogen; D004247:DNA; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; D007610:Kallikreins