Electrochemical evaluation of the reaction rate between methyl viologen mediator and diaphorase enzyme for the electrocatalytic reduction of NAD+ and digital simulation for its voltammetric responses

被引:44
作者
Kim, S
Yun, SE
Kang, C [1 ]
机构
[1] Chonbuk Natl Univ, Inst Agr Sci & Technol, Dept Food Sci & Technol, Chonju 561756, South Korea
[2] Chonbuk Natl Univ, Dept Chem, Chonju 561756, South Korea
来源
JOURNAL OF ELECTROANALYTICAL CHEMISTRY | 1999年 / 465卷 / 02期
关键词
NAD(+); NADH; diaphorase; rate constant; digital simulation; enzyme catalysis;
D O I
10.1016/S0022-0728(99)00074-1
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
The electrocatalytic reduction of NAD(+) using diaphorase enzyme was studied. Methyl viologen was used as an electron transfer mediator between an electrode and the enzyme. A catalytic wave for the reduction of NAD(+) when all the species were in the solution was measured with cyclic voltammetry at a gold-amalgam electrode which showed low background currents at negative potentials. Steady-state currents could be obtained under the conditions of slow scan rate, low methyl viologen concentration, and high NAD(+) concentration as the electrode reaction was converted to an electrochemical-catalytic (EC') reaction. The bimolecular rate constant for the reaction of the reduced methyl viologen with the oxidized diaphorase was estimated as 7.5 x 10(3) M-1 s(-1) from the slope of the current versus [MV2+] plot. Another slope of the current against the square root of the enzyme concentration also gave a close value of 6.7 x 103 M-1 s(-1). In the calculation of the rate constant, the stoichiometric factor when it is not one-to-one was considered. With the evaluated rate constant, digital simulation using the suggested reaction mechanism was compared with the experimentally obtained voltammograms. Satisfactory agreement indicates that the evaluation methods of the rate constant and the suggested mechanism are appropriate for the mediated enzyme-catalyzed electrochemical reactions. (C) 1999 Elsevier Science S.A. All rights reserved.
引用
收藏
页码:153 / 159
页数:7
相关论文
共 31 条
[1]   ELECTROLYTIC REGENERATION OF NADH FROM NAD+ WITH A LIQUID-CRYSTAL MEMBRANE ELECTRODE [J].
AIZAWA, M ;
SUZUKI, S ;
KUBO, M .
BIOCHIMICA ET BIOPHYSICA ACTA, 1976, 444 (03) :886-892
[2]  
Bard A. J., 1980, ELECTROCHEMICAL METH, P143
[3]  
BARD AJ, 1980, ELECTROCHEMICAL METH, P700
[4]  
BARD AJ, 1980, ELECTROCHEMICAL METH, P457
[5]  
BARTLETT PN, 1993, J ELECTROANAL CHEM, V362, P1
[6]   DIGITAL-SIMULATION OF HOMOGENEOUS ENZYME-KINETICS FOR AMPEROMETRIC REDOX-ENZYME ELECTRODES [J].
BATTAGLINI, F ;
CALVO, EJ .
ANALYTICA CHIMICA ACTA, 1992, 258 (01) :151-160
[7]  
BOURDILLON C, 1993, J AM CHEM SOC, V115, P2
[8]   EFFECT OF VIOLOGEN STRUCTURE ON ELECTROREDUCTION OF NAD+ CATALYZED BY DIAPHORASE IMMOBILIZED ON ELECTRODES [J].
CHANG, HC ;
MATSUE, T ;
UCHIDA, I ;
OSA, T .
CHEMISTRY LETTERS, 1989, (07) :1119-1122
[9]   MEDIATED, ANAEROBIC VOLTAMMETRY OF SULFITE OXIDASE [J].
COURY, LA ;
OLIVER, BN ;
EGEKEZE, JO ;
SOSNOFF, CS ;
BRUMFIELD, JC ;
BUCK, RP ;
MURRAY, RW .
ANALYTICAL CHEMISTRY, 1990, 62 (05) :452-458
[10]   ELECTROCHEMICAL STUDY OF KINETICS OF ELECTRON-TRANSFER BETWEEN SYNTHETIC ELECTRON-ACCEPTORS AND REDUCED MOLYBDOHEME PROTEIN SULFITE OXIDASE [J].
COURY, LA ;
MURRAY, RW ;
JOHNSON, JL ;
RAJAGOPALAN, KV .
JOURNAL OF PHYSICAL CHEMISTRY, 1991, 95 (15) :6034-6040