title: Modulating furin activity with designed mini-PDX peptides: synthesis and in vitro kinetic evaluation.
abstract: A peptide was designed from reactive site loop structure of alpha1 Antitrypsin Portland known as alpha1 PDX as a novel mini-PDX inhibitor of furin. The sequence was derived from (367-394) that contains the crucial furin cleavage motif RIPR382. A P3 mutant replacing Ile380 by Leu was prepared as a first model peptide. A Cys residue was inserted at each terminal of the peptide for purpose of cyclisation which was accomplished by air or iodine-induced oxidation. This mini-PDX peptide both cyclic and acyclic form inhibited in vitro furin activity (IC50 in nM) when measured against either substrates Boc-RVRRdown double arrow MCA or QVEGF-C [Abz-QVHSIIRRdown double arrow SLP-Y(NO2)-A-CONH2, Abz=2-amino benzoic acid and Y(NO2)=3-nitro tyrosine], latter being derived from vascular endothelial growth factor-C (VEGF-C) processing site. The geometrically constrained structure mimicking PDX reactive loop is crucial for enzyme inhibition. Our study further revealed that both mini-PDX peptides inactivate furin in a slow tight binding manner, with disulfide-bridged cyclic form being slightly more potent. Unlike PDX, these peptides inhibit furin via a different mechanistic pathway. The study provides an alternate strategy for development of efficient peptide-based inhibitors of Proprotein Convertases including furin.
authors.affiliation: Diseases of Aging Program, Regional Protein Chemistry Center, Ottawa Health Research Institute, University of Ottawa, Loeb Building, 725 Parkdale Ave, Ottawa, ON, K1Y 4E9, Canada. abasak@ohri.ca
authors.forename: Ajoy
authors.initials: A
authors.lastname: Basak
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Lotfipour
mesh_terms: D000595:Amino Acid Sequence; D003374:Coumarins / Q000378:metabolism; D045683:Furin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis* / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D042582:Vascular Endothelial Growth Factor C / Q000031:analogs & derivatives / Q000378:metabolism; D000515:alpha 1-Antitrypsin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D003374:Coumarins; D009842:Oligopeptides; D010455:Peptides; D042582:Vascular Endothelial Growth Factor C; D000515:alpha 1-Antitrypsin; C089959:tert-butoxycarbonyl-arginyl-valyl-arginyl-arginyl-methylcoumarin amide; D045683:Furin