C-Npys (S-3-nitro-2-pyridinesulfenyl) and peptide derivatives can inhibit a serine-thiol proteinase activity from Paracoccidioides brasiliensis.
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.
Matsuo
Alisson L
AL
Department of Microbiology, Immunology and Parasitology, Cell Biology Division, Federal University of São Paulo, São Paulo, SP 04023-062, Brazil.
Carmona
Adriana K
AK
Silva
Luiz S
LS
Cunha
Carlos E L
CE
Nakayasu
Ernesto S
ES
Almeida
Igor C
IC
Juliano
Maria A
MA
Puccia
Rosana
R
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*
D015853:Cysteine Proteinase Inhibitors; D010455:Peptides; D011725:Pyridines; D015842:Serine Proteinase Inhibitors; C065586:3-nitro-2-pyridinesulfenyl; D012697:Serine Endopeptidases; D003546:Cysteine Endopeptidases