The somatostatin-28 convertase of rat brain cortex generates both somatostatin-14 and somatostatin-28.
The products generated after addition of the ARG-LYS esteropeptidase activity purified from rat brain to synthetic somatostatin-28 were analyzed using radioimmunoassay, HPLC and amino acid analysis. In addition to somatostatin-14, both free arginine and free Lysine were identified together with somatostatin-28. The dipeptide ARG-LYS was not present, which indicates that three peptide bonds were hydrolyzed in order to achieve excision of the doublet. Since it is likely that the octacosapeptide is a precursor for both somatostatin-14 and somatostatin-28, these observations add further support to the hypothesis that the convertase is also involved in the in vivo processing of endogenous somatostatin-28.
Gluschankof
P
P
Morel
A
A
Benoit
R
R
Cohen
P
P
D000818:Animals; D001120:Arginine / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D010446:Peptide Fragments / Q000096:biosynthesis*; D051381:Rats; D013004:Somatostatin / Q000096:biosynthesis* / Q000378:metabolism; D053561:Somatostatin-28
D010446:Peptide Fragments; D013004:Somatostatin; D053561:Somatostatin-28; C037197:somatostatin 28-(1-12); D001120:Arginine; D010450:Endopeptidases; C045514:somatostatin-28 convertase; D008239:Lysine