Solid-phase library synthesis, screening, and selection of tight-binding reduced peptide bond inhibitors of a recombinant Leishmania mexicana cysteine protease B.
A one-bead-two-compound inhibitor library was synthesized by the split-mix method for the identification of inhibitors of a recombinant cysteine protease from Leishmania mexicana, CPB2.8DeltaCTE. The inhibitor library was composed of octapeptides with a centrally located reduced bond introduced by reductive amination of the resin-bound amines with Fmoc amino aldehydes. The library was screened on solid phase, and less than 1% of the library contained active compounds. The inhibitors displayed great specificity in the subsites flanking the enzyme catalytic triad with Cha and Ile/Leu preferred in P(2), Phe in P(1), Cha and Ile/Leu in P(1)', and Ile/Leu in P(2)'. Some of the inhibitors were resynthesized, and the kinetics of inhibition were determined in solution-phase assays. Most of the inhibitors had micromolar K(i) values, and a few inhibited the enzyme at nanomolar concentrations. One inhibitor, DKHF(CH(2)NH)LLVK (K(i) = 1 microm), was tested for antiparasite efficacy and shown to affect parasite survival with an IC(50) of approximately 50 microm.
St  Hilaire
Phaedria M
PM
Department of Chemistry, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark. pms@crc.dk
Alves
Lira C
LC
Herrera
Fatima
F
Renil
Manat
M
Sanderson
Sanya J
SJ
Mottram
Jeremy C
JC
Coombs
Graham H
GH
Juliano
Maria A
MA
Juliano
Luiz
L
Arevalo
Jorge
J
Meldal
Morten
M
D000586:Amination; D000818:Animals; D020650:Combinatorial Chemistry Techniques; D015853:Cysteine Proteinase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D066298:In Vitro Techniques; D007894:Leishmania mexicana / Q000201:enzymology*; D008264:Macrophages / Q000187:drug effects / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010084:Oxidation-Reduction; D011092:Polyethylene Glycols; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013329:Structure-Activity Relationship
D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; D011994:Recombinant Proteins; C109511:bis(polyoxyethylene bis(amine)); D011092:Polyethylene Glycols