title: C-Npys (S-3-nitro-2-pyridinesulfenyl) and peptide derivatives can inhibit a serine-thiol proteinase activity from Paracoccidioides brasiliensis.
abstract: The inhibitory capacity of C-Npys (S-[3-nitro-2-pyridinesulfenyl]) derivatives over thiol-containing serine proteases has never been tested. In the present work we used an extracellular serine-thiol proteinase activity from the fungal pathogen Paracoccidioides brasiliensis (PbST) to describe a potent inhibitory capacity of Bzl-C(Npys)KRLTL-NH(2) and Bzl-MKRLTLC(Npys)-NH(2). The assays were performed with PbST enriched upon affinity chromatography in a p-aminobenzamidine (pABA)-Sepharose column. Although PbST can cleave the fluorescence resonance energy transfer peptide Abz-MKRLTL-EDDnp between L-T, the C(Npys) derivatives were not substrates nor were they toxic in a cell detachment assay, allowing therapeutic use. The best inhibitor was Bzl-C(Npys)KRLTL-NH(2) (K(i)=16nM), suggesting that the peptide sequence promoted a favorable interaction, especially when C(Npys) was placed at a further position from the L-T bond, at the N-terminus. Inhibition was completely reverted with dithioerythritol, indicating that it was due to the reactivity of the C(Npys) moiety with a free SH- group.
authors.affiliation: Department of Microbiology, Immunology and Parasitology, Cell Biology Division, Federal University of São Paulo, São Paulo, SP 04023-062, Brazil.
authors.forename: Alisson L
authors.initials: AL
authors.lastname: Matsuo
authors.forename: Adriana K
authors.initials: AK
authors.lastname: Carmona
authors.forename: Luiz S
authors.initials: LS
authors.lastname: Silva
authors.forename: Carlos E L
authors.initials: CE
authors.lastname: Cunha
authors.forename: Ernesto S
authors.initials: ES
authors.lastname: Nakayasu
authors.forename: Igor C
authors.initials: IC
authors.lastname: Almeida
authors.forename: Maria A
authors.initials: MA
authors.lastname: Juliano
authors.forename: Rosana
authors.initials: R
authors.lastname: Puccia
mesh_terms: D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D010228:Paracoccidioides / Q000201:enzymology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D011725:Pyridines / Q000737:chemistry / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D015853:Cysteine Proteinase Inhibitors; D010455:Peptides; D011725:Pyridines; D015842:Serine Proteinase Inhibitors; C065586:3-nitro-2-pyridinesulfenyl; D012697:Serine Endopeptidases; D003546:Cysteine Endopeptidases