A chiral ligand exchange CE essay with zinc(II)-L-valine complex for determining enzyme kinetic constant of L-amino acid oxidase.
A new strategy for the enantioseparation of D,L-amino acids employing the principle of ligand exchange capillary electrophoresis with Zn(II)-L-valine complex as a chiral selecting system in the presence of beta-cyclodextrin has been designed. Successful enantioseparation of label free and labeled amino acids have been achieved with a buffer of 100.0mM boric acid, 5.0mM ammonium acetate, 4.0mM beta-cyclodextrin, 4.0mM ZnSO(4) and 8.0mM L-valine at pH 8.1. This new method was shown to be applicable to the quantitative analysis of label free D- and L-aromatic amino acids. Furthermore, the expanding enzymatic use of L-amino acid oxidase to incubate with different L-amino acids has allowed understanding of the substrate's specificity. An on-column incubation assay has been developed to study the L-amino acid oxidase's catalytic efficiency. It was demonstrated that the enzyme kinetic constant could be determined by using this new method.
Qi
Li
L
Beijing National Laboratory of Molecular Science, Chinese Academy of Sciences, Beijing, China. qili@iccas.ac.cn
Yang
Gengliang
G
Zhang
Haizhi
H
Qiao
Juan
J
D000818:Animals; D001671:Biochemistry / Q000379:methods*; D002384:Catalysis; D002623:Chemistry Techniques, Analytical; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007651:Keto Acids / Q000737:chemistry; D007700:Kinetics; D050830:L-Amino Acid Oxidase / Q000032:analysis*; D008024:Ligands; D012910:Snake Venoms / Q000201:enzymology; D012911:Snakes; D013237:Stereoisomerism; D013379:Substrate Specificity; D014633:Valine / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
D007651:Keto Acids; D008024:Ligands; D012910:Snake Venoms; C013082:alpha-ketoisocaproic acid; D050830:L-Amino Acid Oxidase; D014633:Valine; D015032:Zinc