title: Expression and characterization of the Babesia bigemina cysteine protease BbiCPL1.
abstract: BbiCPL1 was the first papain-like cysteine protease from a piroplasm to be identified with proteolytic activity. Here we report the improved production of the active recombinant enzyme, and the biochemical characterization of this potential drug target. BbiCPL1 showed characteristic properties of its class, including hydrolysis of papain-family peptide substrates, an acidic pH optimum, requirement of a reducing environment for maximum activity, and inhibition by standard cysteine protease inhibitors such as E-64, leupeptin, ALLN and cystatin. The optimum pH for the protease activity against peptide substrates was 5.5, but enzymatic activity was observed between pH 4.0 and pH 9.0. At slightly basic pH 7.5, BbiCPL1 maintained 83% of maximum activity, suggesting a role in cytosol environment.
authors: Centro de Malária e Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Lisboa, Portugal. tmlmartins@gmail.com
authors: Tiago M
authors: TM
authors: Martins
authors: Virgílio E
authors: VE
authors: do Rosário
authors: Ana
authors: A
authors: Domingos
mesh_terms: D000818:Animals; D001403:Babesia / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D057056:Cysteine Proteases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004795:Enzyme Stability; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D015800:Protozoan Proteins; D011994:Recombinant Proteins; D057056:Cysteine Proteases