title: Kinetic analysis of duck epsilon-crystallin with L-lactate dehydrogenase activity: determination of kinetic constants and comparison of substrate specificity.
abstract: A systematic analysis of the kinetic properties of duck lens epsilon-crystallin with lactate dehydrogenase [LDH, (E.C. 1.1.1.27)] activity was carried out by employing some 19 different alpha-keto acids as substrates for this NADH-dependent LDH-catalyzed reaction. The steady-state Michaelis and catalytic constants (Km, kcat) were determined for a broad range of organic compounds. The results provide important insights regarding the binding and affinity of substrates to active sites of this enzyme crystallin and indicate a great potential for the application of the stable epsilon-crystallin as a catalyst to the synthesis of some important chiral alpha-hydroxyacids in a convenient and efficient way. It is also demonstrated for the first time that in addition to the enzymatic activity of lactate dehydrogenase, duck epsilon-crystallin also possesses the enzymatic activity of malate dehydrogenase.
authors.affiliation: Graduate Institute of Biochemical Sciences, National Taiwan University, Taipei.
authors.forename: C Y
authors.initials: CY
authors.lastname: Wu
authors.forename: S T
authors.initials: ST
authors.lastname: Chen
authors.forename: S H
authors.initials: SH
authors.lastname: Chiou
authors.forename: K T
authors.initials: KT
authors.lastname: Wang
mesh_terms: D000818:Animals; D001665:Binding Sites; D002645:Chickens; D003459:Crystallins / Q000302:isolation & purification / Q000378:metabolism*; D004372:Ducks; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000302:isolation & purification / Q000378:metabolism*; D009132:Muscles / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D003459:Crystallins; D007770:L-Lactate Dehydrogenase