tailieunhanh - Báo cáo khoa học: Structural and functional insights into Erwinia carotovora L-asparaginase

Bacterial l-asparaginases are enzymes that catalyze the hydrolysis of l-asparagine to aspartic acid. For the past 30 years, these enzymes have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukemia. | ễFEBS Journal Structural and functional insights into Erwinia carotovora L-asparaginase Anastassios C. Papageorgiou1 Galina A. Posypanova2 Charlotta S. Andersson1 Nikolay N. Sokolov3 and Julya Krasotkina3 1 Turku Centre for Biotechnology University of Turku and Abo Akademi University Finland 2 Institute of Molecular Medicine Russian Academy of MedicalSciences Moscow Russia 3 Institute of BiomedicalChemistry Russian Academy of MedicalSciences Moscow Russia Keywords asparaginase crystal structure enzyme therapy Erwinia leukemia treatment Correspondence A. C. Papageorgiou Turku Centre for Biotechnology University of Turku and Abo Akademi University Turku 20520 Finland Fax 358 2 3338000 Tel 358 2 3338012 E-mail Received 26 May 2008 revised 22 June 2008 accepted 26 June 2008 doi Bacterial L-asparaginases are enzymes that catalyze the hydrolysis of L-asparagine to aspartic acid. For the past 30 years these enzymes have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukemia. Their intrinsic low-rate glutaminase activity however causes serious side-effects including neurotoxicity hepatitis coagulopathy and other dysfunctions. Erwinia carotovora asparaginase shows decreased glutaminase activity so it is believed to have fewer sideeffects in leukemia therapy. To gain detailed insights into the properties of E. carotovora asparaginase combined crystallographic thermal stability and cytotoxic experiments were performed. The crystal structure of E. carotovora L-asparaginase in the presence of L-Asp was determined at A resolution and refined to an Rcryst of Rfree with good stereochemistry. Cytotoxicity measurements revealed that E. carotovora asparaginase is 30 times less toxic than the Escherichia coli enzyme against human leukemia cell lines. Moreover denaturing experiments showed that E. carotovora asparaginase has decreased thermodynamic stability as compared to the