A chiral ligand exchange CE essay with zinc(II)-L-valine complex for determining enzyme kinetic constant of L-amino acid oxidase

Talanta. 2010 Jun 15;81(4-5):1554-9. doi: 10.1016/j.talanta.2010.03.001. Epub 2010 Mar 12.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biochemistry / methods*
  • Catalysis
  • Chemistry Techniques, Analytical*
  • Electrophoresis, Capillary / instrumentation
  • Electrophoresis, Capillary / methods*
  • Hydrogen-Ion Concentration
  • Keto Acids / chemistry
  • Kinetics
  • L-Amino Acid Oxidase / analysis*
  • Ligands
  • Snake Venoms / enzymology
  • Snakes
  • Stereoisomerism
  • Substrate Specificity
  • Valine / chemistry*
  • Zinc / chemistry*

Substances

  • Keto Acids
  • Ligands
  • Snake Venoms
  • alpha-ketoisocaproic acid
  • L-Amino Acid Oxidase
  • Valine
  • Zinc