Expression and characterization of the Babesia bigemina cysteine protease BbiCPL1

• Published in: Acta tropica Vol. 121; no. 1; pp. 1 - 5
• Main Authors: Martins, Tiago M., do Rosário, Virgílio E., Domingos, Ana
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.01.2012; Elsevier
• Subjects: Animals; Babesia - enzymology; Babesia - genetics; Babesia bigemina; BbiCPL1; Biological and medical sciences; Cloning, Molecular; Cystatin; Cysteine protease; Cysteine Proteases - chemistry; Cysteine Proteases - genetics; Cysteine Proteases - metabolism; cysteine proteinase inhibitors; cysteine proteinases; cytosol; drugs; enzyme activity; Enzyme Stability; Gene Expression; General aspects; Hydrogen-Ion Concentration; hydrolysis; Kinetics; Medical sciences; Oxidation-Reduction; proteolysis; Protozoan Proteins - chemistry; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; Recombinant expression; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Substrate Specificity; Babesia bigemina; Recombinant expression; Cysteine protease; BbiCPL1; Protozoa; Peptidases; Apicomplexa; Cysteine; Enzyme; Hydrolases; Tropical medicine
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2011.09.008

BbiCPL1 showed characteristic properties of a cysteine protease. At pH 7.5, BbiCPL1 maintained 83% of maximum activity, suggesting a role in cytosol environment. [Display omitted] ► The cysteine protease BbiCPL1 showed characteristic properties of its class. ► BbiCPL1 showed unusual high activity at slightly basic pH. ► BbiCPL1 apparently does not participate in the invasion of erythrocytes. 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.