title: Chlamydia protease-like activity factor (CPAF): characterization of proteolysis activity in vitro and development of a nanomolar affinity CPAF zymogen-derived inhibitor.
abstract: During infection of epithelial cells, the obligate intracellular pathogen Chlamydia trachomatis secretes the serine protease Chlamydia protease-like activity factor (CPAF) into the host cytosol to regulate a range of host cellular processes through targeted proteolysis. Here we report the development of an in vitro assay for the enzyme and the discovery of a cell-permeable CPAF zymogen-based peptide inhibitor with nanomolar inhibitory affinity. Treating C. trachomatis-infected HeLa cells with this inhibitor prevented CPAF cleavage of the intermediate filament vimentin and led to the loss of vimentin cage surrounding the intracellular vacuole. Because Chlamydia is a genetically intractable organism, this inhibitor may serve as a tool for understanding the role of CPAF in pathogenesis.
authors.affiliation: Department of Chemistry, Duke University, Duke University Medical Center, Durham, North Carolina 27708, United States.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Bednar
authors.forename: Ine
authors.initials: I
authors.lastname: Jorgensen
authors.forename: Raphael H
authors.initials: RH
authors.lastname: Valdivia
authors.forename: Dewey G
authors.initials: DG
authors.lastname: McCafferty
mesh_terms: D000595:Amino Acid Sequence; D002692:Chlamydia trachomatis / Q000187:drug effects / Q000201:enzymology*; D010450:Endopeptidases / Q000737:chemistry* / Q000378:metabolism; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D007424:Intracellular Fluid / Q000201:enzymology; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry / Q000502:physiology; D010455:Peptides / Q000037:antagonists & inhibitors*; D011480:Protease Inhibitors / Q000737:chemistry*; D011485:Protein Binding; D014617:Vacuoles / Q000201:enzymology; D014746:Vimentin / Q000037:antagonists & inhibitors / Q000737:chemistry
chemical_list: D004792:Enzyme Precursors; D010455:Peptides; D011480:Protease Inhibitors; D014746:Vimentin; D010450:Endopeptidases; D010447:Peptide Hydrolases; C425923:CPA factor