Kinetics of the H2O2-dependent ligninase-catalyzed oxidation of veratryl alcohol in the presence of cationic surfactant studied by spectrophotometric technique.
The kinetics of ligninase-catalyzed oxidation of veratryl alcohol (VA) by H(2)O(2) in the aqueous medium containing cationic surfactant cetyltrimethylammonium bromide (CTAB) has been investigated using spectrophotometric technique. Steady-state kinetic studies at different concentrations of CTAB indicate that the reaction follows a ping pong mechanism and the mechanism always holds but the kinetic parameters vary with CTAB concentrations. CTAB is a weak inhibitor for ligninase; it lowers the maximum initial velocity. CTAB also causes the Michaelis constant of H(2)O(2) to decrease dramatically and that of VA to increase markedly. Based on the changes in kinetic parameters of the enzyme-catalyzed reaction at different CTAB concentrations (lower than, near to and larger than its critical micelle concentration) and the effects of the CTAB monomer and the micelles on the spectra of VA and its corresponding aldehyde, a conclusion could be made that modification of the enzymatic protein by the surfactant monomer should be responsible for the above-mentioned results.
Liu
Airong
A
Key Lab for Colloid and Interface Chemistry of the Education Ministry of China, Shandong University, Jinan 250100, People's Republic of China.
Huang
Xirong
X
Song
Shaofang
S
Wang
Dan
D
Lu
Xuemei
X
Qu
Yinbo
Y
Gao
Peiji
P
D001592:Benzyl Alcohols / Q000737:chemistry / Q000378:metabolism*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism*; D013053:Spectrophotometry; D013501:Surface-Active Agents / Q000378:metabolism
D001592:Benzyl Alcohols; D002593:Cetrimonium Compounds; D013501:Surface-Active Agents; D006861:Hydrogen Peroxide; D010105:Oxygenases; C044391:ligninase; C042197:veratryl alcohol; D000077286:Cetrimonium