title: Combinatorial library of peptidotriazoles: identification of [1,2,3]-triazole inhibitors against a recombinant Leishmania mexicana cysteine protease.
abstract: A library consisting of about half of 800 000 possible peptidotriazoles on 450 000 beads was prepared by solid-phase peptide synthesis combined with a regiospecific copper(I)-catalyzed 1,3-dipolar cycloaddition between a resin-bound alkyne and a protected amino azide. The central [1,2,3]-triazole was flanked on each side by two randomized amino acids introduced in a combinatorial approach. Importantly, the formation of the triazole could be performed quantitatively in a randomized fashion. The library was screened on solid phase for inhibitory effect against a recombinant cysteine protease, Leishmania mexicana CPB2.8DeltaCTE and sorted by a high-throughput instrument, COPAS beadsorter (up to 200 000 beads/h). Forty-eight hits were analyzed by MALDI-TOF MS providing structural information about the protease specificity, and 23 peptidotriazoles were resynthesized and evaluated in solution, with the best inhibitor displaying a K(i) value of 76 nM. A one-pot procedure was used to convert Fmoc-amino azides into their corresponding Boc derivatives. The crucial influence of weak interactions with a spacer used for detection by MALDI-TOF MS on screening results was observed.
authors.affiliation: Center for Solid-Phase Organic Combinatorial Chemistry, Department of Chemistry, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark.
authors.forename: Christian W
authors.initials: CW
authors.lastname: Tornøe
authors.forename: Sanya J
authors.initials: SJ
authors.lastname: Sanderson
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Mottram
authors.forename: Graham H
authors.initials: GH
authors.lastname: Coombs
authors.forename: Morten
authors.initials: M
authors.lastname: Meldal
mesh_terms: D020169:Caspases; D020650:Combinatorial Chemistry Techniques; D057056:Cysteine Proteases; D015723:Gene Library; D007894:Leishmania mexicana; D008958:Models, Molecular; D015394:Molecular Structure; D014230:Triazoles
chemical_list: D014230:Triazoles; D057056:Cysteine Proteases; D020169:Caspases