Open AccessCrystallization and preliminary crystallographic analysis of l ‐asparaginase from Erwinia carotovora
Author(s) -
Wikman Linnea E. K.,
Krasotkina Julya,
Kuchumova Anastasia,
Sokolov Nikolay N.,
Papageorgiou Anastassios C.
Publication year - 2005
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309105008249
Subject(s) - monoclinic crystal system , asparagine , chemistry , crystallization , asparaginase , crystallography , homotetramer , peg ratio , enzyme , protein crystallization , crystal structure , protein subunit , biochemistry , lymphoblastic leukemia , medicine , organic chemistry , immunology , finance , leukemia , economics , gene
Bacterial l ‐asparaginases have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukaemia for over 30 y. However, their use is limited owing to the glutaminase activity of the administered enzymes, which results in serious side effects. In contrast, l ‐asparaginase from Erwinia carotovora exhibits low glutaminase activity at physiological concentrations of l ‐asparagine and l ‐glutamine in the blood. Recombinant Er. carotovora l ‐asparaginase was crystallized in the presence of l ‐glutamate by the hanging‐drop vapour‐diffusion method using 10 mg ml −1 purified enzyme, 16–18%( w / v ) PEG 3350 and 0.2 M NaF. X‐ray diffraction data were collected to 2.6 Å at 293 K using an in‐house rotating‐anode generator. The crystals belong to the monoclinic P 2 1 space group, with unit‐cell parameters a = 78.0, b = 112.3, c = 78.7 Å, β = 101.9° and a homotetramer in the crystallographic asymmetric unit. A molecular‐replacement solution has been found and refinement is currently in progress. The crystal structure may provide leads towards protein‐engineering efforts aimed at safer asparaginase administration in leukaemia treatment.