Solid-Phase Library Synthesis, Screening, and Selection of Tight-Binding Reduced Peptide Bond Inhibitors of a Recombinant Leishmania mexicana Cysteine Protease B

• Published in: Journal of medicinal chemistry Vol. 45; no. 10; pp. 1971 - 1982
• Main Authors: ST. HILAIRE, Phaedria M., ALVES, Lira C., HERRERA, Fatima, RENIL, Manat, SANDERSON, Sanya J., MOTTRAM, Jeremy C., COOMBS, Graham H., JULIANO, Maria A., JULIANO, Luiz, AREVALO, Jorge, MELDAL, Morten
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09-05-2002
• Subjects: Amination; Animals; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiparasitic agents; Biological and medical sciences; Combinatorial Chemistry Techniques; Cysteine Proteinase Inhibitors - chemical synthesis; Cysteine Proteinase Inhibitors - chemistry; Cysteine Proteinase Inhibitors - pharmacology; Drug Evaluation, Preclinical; In Vitro Techniques; Leishmania mexicana - enzymology; Macrophages - drug effects; Macrophages - parasitology; Medical sciences; Mice; Mice, Inbred BALB C; Models, Molecular; Oligopeptides - chemical synthesis; Oligopeptides - chemistry; Oligopeptides - pharmacology; Oxidation-Reduction; Pharmacology. Drug treatments; Polyethylene Glycols; Recombinant Proteins - antagonists & inhibitors; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Structure-Activity Relationship; Peptides; Cysteine endopeptidases; Combinatorial chemistry; Substrate enzyme complex; Modeling; Leishmania mexicana; Octapeptide; Aminoaldehyde; Structure activity relation; Chemical compound library; Parasiticid; Molecular model; Chemical synthesis; Kinetoplastida; Protozoa; Enzyme; Enzyme inhibitor; Inhibitor enzyme complex; In vitro; Pseudopeptide; Peptidases; Screening; Polypeptide; Hydrolases; Solid phase
• ISSN: 0022-2623; 1520-4804
• DOI: 10.1021/jm0110901

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.