Inhibition of human serum oxytocinase (cystine aminopeptidase, E. C. 3.4.11.3) by GnRH peptides.
The hydrolysis of H-Cys(Bzl)-NH-Meq by human serum oxytocinase (E.C. 3.4.11.3) was inhibited non-competitively by various pyroglutamyl peptides. The most effective were the chicken GnRH II (Ki = 6 x 10(-6) mol l-1) and salmon GnRH (Ki = 12 x 10(-6) mol l-1), while the inhibitory potency of human GnRH was substantially lower (Ki = 60.0 x 10(-6) mol l-1). Variations in inhibitory potency of individual peptides reflected mostly the differences in N-terminal and C-terminal parts of the molecules.
Masková
H P
HP
Department of Peptide Biochemistry, Czechoslovak Academy of Sciences, Praha.
Burbach
J P
JP
Kokotos
G
G
Tzougraki
C
C
Barth
T
T
D000595:Amino Acid Sequence; D002855:Chromatography, Thin Layer; D010122:Cystinyl Aminopeptidase / Q000037:antagonists & inhibitors* / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D008969:Molecular Sequence Data; D011761:Pyrrolidonecarboxylic Acid / Q000494:pharmacology
D007987:Gonadotropin-Releasing Hormone; D010122:Cystinyl Aminopeptidase; D011761:Pyrrolidonecarboxylic Acid