Aminoethyl benzenesulfonyl fluoride and its hexapeptide (Ac-VFRSLK) conjugate are both in vitro inhibitors of subtilisin kexin isozyme-1.
Using a number of intramolecularly quenched fluorogenic (IQF) substrates encompassing the subtilisin kexin isozyme-1 (SKI-1)-mediated cleavage sites of various viral glycoproteins, it is revealed that 4-[2-Aminoethyl BenzeneSulfonylFluoride (AEBSF) can inhibit the proteolytic activity of SKI-1 mostly in a competitive manner. The measured IC50 values range from 200 to 800 nM depending on the nature of the substrate used. This is the first in vitro demonstration of a non-peptide inhibitor of SKI-1. In an effort to enhance the selectivity and potency of SKI-1 inhibition, a hexapeptidyl derivative containing SKI-1 consensus sequence, Ac-Val-Phe-Arg-Ser-Leu-Lys-AEBSF, was prepared. The peptide sequence was derived from the primary auto-activation site of prodomain of SKI-1 itself terminating at Leu-Lys138 and contains the crucial P4-basic and P2 alkyl side chain containing hydrophobic amino acids. Like AEBSF, the hexapeptidyl-AEBSF analog blocked SKI-1 cleavages of all IQF-substrates tested but with enhanced efficiency.
Basak
Sarmistha
S
Diseases of Aging Program, Regional Protein Chemistry Center, Ottawa Health Research Institute, 725 Parkdale Avenue, Ottawa, ON, Canada K1Y 4E9.
Stewart
Nicolas A
NA
Chrétien
Michel
M
Basak
Ajoy
A
D000595:Amino Acid Sequence; D002384:Catalysis / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D043484:Proprotein Convertases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020860:Subtilisin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013450:Sulfones / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D010455:Peptides; D013450:Sulfones; C002010:4-(2-aminoethyl)benzenesulfonylfluoride; D043484:Proprotein Convertases; D012697:Serine Endopeptidases; C115575:membrane-bound transcription factor peptidase, site 1; D020860:Subtilisin