title: Evaluation of a two-stage screening procedure in the combinatorial search for serine protease-like activity.
abstract: A series of peptidosteroid derivatives containing two independent peptide chains in which Ser and His are incorporated were synthesized by solid-phase peptide synthesis. The activity of the different compounds in the hydrolysis of the activated substrate NF31 was assessed in a stepwise fashion. First, the different resin-bound derivatives 6a-l and 6x-z were individually assayed for serine esterification in the absence of water. The use of a colored substrate allowed for a visual identification of the most active compounds. Through the inclusion of control substances, the involvement of histidine in the mechanism for serine acylation was shown. Second, the hydrolysis and methanolysis of the different acylated derivatives 8a-l and 8x were evaluated using UV spectroscopy, again indicating the involvement of histidine. The feasibility of applying the above procedures in a combinatorial context was proven via the screening of artificial libraries, created by mixing the different resin-bound peptidosteroid compounds. In this respect, the use of a photocleavable linker allowed for the unambiguous structural characterization of the selected members via application of single-bead electrospray tandem mass spectrometry.
authors.affiliation: Laboratory of Organic Synthesis, Department of Organic Chemistry, Ghent University, Krijgslaan 281, B-9000 Gent, Belgium.
authors.forename: Annemieke
authors.initials: A
authors.lastname: Madder
authors.forename: Liu
authors.initials: L
authors.lastname: Li
authors.forename: Hilde
authors.initials: H
authors.lastname: De Muynck
authors.forename: Nadia
authors.initials: N
authors.lastname: Farcy
authors.forename: Dirk
authors.initials: D
authors.lastname: Van Haver
authors.forename: Franky
authors.initials: F
authors.lastname: Fant
authors.forename: Gerd
authors.initials: G
authors.lastname: Vanhoenacker
authors.forename: Pat
authors.initials: P
authors.lastname: Sandra
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Davis
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: De Clercq
mesh_terms: D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D015195:Drug Design; D006639:Histidine / Q000737:chemistry; D019151:Peptide Library; D010455:Peptides / Q000138:chemical synthesis* / Q000494:pharmacology; D012694:Serine / Q000737:chemistry; D012697:Serine Endopeptidases / Q000138:chemical synthesis* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013256:Steroids / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: D019151:Peptide Library; D010455:Peptides; D013256:Steroids; D012694:Serine; D006639:Histidine; D012697:Serine Endopeptidases