title: Structure-Based Design of β5c Selective Inhibitors of Human Constitutive Proteasomes.
abstract: This work reports the development of highly potent and selective inhibitors of the β5c catalytic activity of human constitutive proteasomes. The work describes the design principles, large hydrophobic P3 residue and small hydrophobic P1 residue, that led to the synthesis of a panel of peptide epoxyketones; their evaluation and the selection of the most promising compounds for further analyses. Structure-activity relationships detail how in a logical order the β1c/i, β2c/i, and β5i activities became resistant to inhibition as compounds were diversified stepwise. The most effective compounds were obtained as a mixture of cis- and trans-biscyclohexyl isomers, and enantioselective synthesis resolved this issue. Studies on yeast proteasome structures complexed with some of the compounds provide a rationale for the potency and specificity. Substitution of the N-terminus in the most potent compound for a more soluble equivalent led to a cell-permeable molecule that selectively and efficiently blocks β5c in cells expressing both constitutive proteasomes and immunoproteasomes.
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Bo-Tao
authors.initials: BT
authors.lastname: Xin
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Gerjan
authors.initials: G
authors.lastname: de Bruin
authors.affiliation: Center for Integrated Protein Science at the Department Chemie, Lehrstuhl für Biochemie, Technische Universität München , 85748 Garching, Germany.
authors.forename: Eva M
authors.initials: EM
authors.lastname: Huber
authors.affiliation: Department of Hematology and Oncology, Kantonsspital St. Gallen , 9007 St. Gallen, Switzerland.
authors.forename: Andrej
authors.initials: A
authors.lastname: Besse
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Bogdan I
authors.initials: BI
authors.lastname: Florea
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Dmitri V
authors.initials: DV
authors.lastname: Filippov
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Gijsbert A
authors.initials: GA
authors.lastname: van der Marel
authors.affiliation: Department of Pharmacology and Toxicology and Norris Cotton Cancer Center, Geisel Cancer School of Medicine at Dartmouth , 1 Medical Center Drive HB7936, Lebanon, New Hampshire 03756, United States.
authors.forename: Alexei F
authors.initials: AF
authors.lastname: Kisselev
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Mario
authors.initials: M
authors.lastname: van der Stelt
authors.affiliation: Department of Hematology and Oncology, Kantonsspital St. Gallen , 9007 St. Gallen, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Driessen
authors.affiliation: Center for Integrated Protein Science at the Department Chemie, Lehrstuhl für Biochemie, Technische Universität München , 85748 Garching, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Groll
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Herman S
authors.initials: HS
authors.lastname: Overkleeft
mesh_terms: D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D015195:Drug Design; D006801:Humans; D008958:Models, Molecular; D015394:Molecular Structure; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D061988:Proteasome Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D061988:Proteasome Inhibitors; D046988:Proteasome Endopeptidase Complex