title: Unnatural amino acids increase activity and specificity of synthetic substrates for human and malarial cathepsin C.
abstract: Mammalian cathepsin C is primarily responsible for the removal of N-terminal dipeptides and activation of several serine proteases in inflammatory or immune cells, while its malarial parasite ortholog dipeptidyl aminopeptidase 1 plays a crucial role in catabolizing the hemoglobin of its host erythrocyte. In this report, we describe the systematic substrate specificity analysis of three cathepsin C orthologs from Homo sapiens (human), Bos taurus (bovine) and Plasmodium falciparum (malaria parasite). Here, we present a new approach with a tailored fluorogenic substrate library designed and synthesized to probe the S1 and S2 pocket preferences of these enzymes with both natural and a broad range of unnatural amino acids. Our approach identified very efficiently hydrolyzed substrates containing unnatural amino acids, which resulted in the design of significantly better substrates than those previously known. Additionally, in this study significant differences in terms of the structures of optimal substrates for human and malarial orthologs are important from the therapeutic point of view. These data can be also used for the design of specific inhibitors or activity-based probes.
authors.affiliation: Division of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370, Wrocław, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Poreba
authors.forename: Marko
authors.initials: M
authors.lastname: Mihelic
authors.forename: Priscilla
authors.initials: P
authors.lastname: Krai
authors.forename: Jelena
authors.initials: J
authors.lastname: Rajkovic
authors.forename: Artur
authors.initials: A
authors.lastname: Krezel
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Pawelczak
authors.forename: Michael
authors.initials: M
authors.lastname: Klemba
authors.forename: Dusan
authors.initials: D
authors.lastname: Turk
authors.forename: Boris
authors.initials: B
authors.lastname: Turk
authors.forename: Rafal
authors.initials: R
authors.lastname: Latajka
authors.forename: Marcin
authors.initials: M
authors.lastname: Drag
mesh_terms: D000596:Amino Acids / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D020789:Cathepsin C / Q000737:chemistry* / Q000378:metabolism; D002417:Cattle; D004151:Dipeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D015394:Molecular Structure; D010963:Plasmodium falciparum / Q000737:chemistry / Q000201:enzymology*; D015800:Protozoan Proteins / Q000737:chemistry* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D004151:Dipeptides; D015800:Protozoan Proteins; D020789:Cathepsin C