Design and synthesis of novel inhibitors of prohormone convertases.
Prohormone convertase-1 (PC1) and furin are subtilisin-like endopeptidases involved in the biosynthesis of peptide hormones. Five decapeptides representing the junction between the pro-region and the catalytic region of PC1 were prepared. The core sequence corresponded to D-Tyr-Arg-Ser-Lys-Arg- Xaa-Val-Gln-Lys-Asp where D-Tyr replaces the native Glu residue and Xaa, representing the P1' position, corresponds to L-Ser, L-Leu or the unnatural amino acids, D-Ser, beta-Ala, gamma-Abu, beta-Cha or gamma-Hyp. Another analog incorporating an Orn residue in place of the Arg at the P1 site was also prepared. These peptides, synthesized by solid-phase Fmoc chemistry, were fully characterized by FAB-MS, 1H-NMR and amino acid composition. Except for Orn, gamma-Hyp, L/D-Ser and L-Leu containing analogs, the others were found to be moderate to potent competitive inhibitors of hPC1 activity in the following order: gamma-Abu > beta-Cha > beta-Ala, with Ki values ranging from 1 to 8.6 microM. Both L-Ser and L-Leu analogs were correctly cleaved at the acyl carbon COOH-terminal to the Lys-Arg pair by human PC1, whereas beta-Cha, gamma-Abu, beta-Ala and D-Ser analogs proved to be very poor substrates. The Orn and gamma-Hyp derivatives were not cleaved by the enzyme at all. The three analogs containing beta-Cha, gamma-Abu and beta-Ala also proved to be potent inhibitors of the human furin activity in the following order: beta-Ala > beta-Cha > gamma-Abu, with Ki ranging from 0.8 to 2.2 microM.(ABSTRACT TRUNCATED AT 250 WORDS)
Basak
A
A
Laboratory of Neuropeptides Structure and Metabolism, Clinical Research Institute of Montréal, Québec, Canada.
Jean
F
F
Seidah
N G
NG
Lazure
C
C
D000595:Amino Acid Sequence; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors*; D002851:Chromatography, High Pressure Liquid; D015195:Drug Design; D045683:Furin; D006801:Humans; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D043484:Proprotein Convertases; D011480:Protease Inhibitors / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013381:Subtilisins / Q000037:antagonists & inhibitors*
D010455:Peptides; D011480:Protease Inhibitors; D043484:Proprotein Convertases; D013381:Subtilisins; D045683:Furin; D016282:Aspartic Acid Endopeptidases