The cleavage site specificity of human prostate specific antigen for insulin-like growth factor binding protein-3.
The cleavage site of human insulin-like growth factor binding protein-3 by urinary prostate specific antigen was examined. Human insulin-like growth factor binding protein-3 was incubated with urinary prostate specific antigen at 37 degrees C and its proteolyzed fragments were separated by a reversed phase HPLC followed by N-terminal amino acid sequence analysis, demonstrating that the cleavage mainly occurred at Tyr-159. The synthetic peptide including Tyr-159 was also cleaved at the same site, although its reaction rate was relatively low. These results indicate that human insulin-like growth factor binding protein-3 is specifically cleaved at Tyr-159 by prostate specific antigen. Human insulin-like growth factor binding protein-3 was previously reported to be cleaved at five sites including Arg-97, Arg-132, Tyr-159, Phe-173 and Arg-179 by another group, however, prostate specific antigen preparation is possibly contaminated by trypsin-like protease. In contrast, our purified urinary prostate specific antigen had only a chymotrypsin-like activity, demonstrating that prostate specific antigen has the high substrate specificity for human insulin-like growth factor binding protein-3.
Okabe
E
E
Development and Research Laboratories, JCR Pharmaceuticals, Kobe, Japan. kajihara@jcrpharm.co.jp
Kajihara
J
J
Usami
Y
Y
Hirano
K
K
D000595:Amino Acid Sequence; D002918:Chymotrypsin / Q000378:metabolism*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D017430:Prostate-Specific Antigen / Q000302:isolation & purification* / Q000378:metabolism* / Q000652:urine; D012661:Semen / Q000201:enzymology; D013379:Substrate Specificity
D018972:Insulin-Like Growth Factor Binding Protein 3; D002918:Chymotrypsin; D017430:Prostate-Specific Antigen