NONPOLAR INTERACTIONS IN THE MALEIMIDE INACTIVATION OF HAEMOPHILUS-INFLUENZAE D-LACTATE DEHYDROGENASE

被引:3
作者
DENICOLASEOANE, A [1 ]
ANDERSON, BM [1 ]
机构
[1] VIRGINIA POLYTECH INST & STATE UNIV,DEPT BIOCHEM & NUTR,BLACKSBURG,VA 24061
关键词
D-Lactate dehydrogenase; H; influenzae; Interaction; N-Alkylmaleimide; Nonpolar;
D O I
10.1016/0167-4838(90)90149-A
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
A series of N-alkylmaleimides varying in chain length from N-ethyl up to and including N-heptyl, was shown to effectively inactive Haemophilus influenzae D-lactate dehydrogenase at pH 7.0 and 25°C in processes proposed to involve covalent modification of cysteine residues. The inactivation proceeded through an initial reversible binding of maleimides facilitated by nonpolar interactions with a hydrophobic region of the enzyme. Subsequent irreversible inactivation of the enzyme indicated the modification of a fast-reacting group leading to approx. 80% loss of enzyme activity followed by a second slower-reacting modification process. At saturating concentrations of maleimides, the second inactivation process exhibited a common pseudo-first-order rate constant of 0.6 min-1. The initial reversible binding of N-alkylmaleimides resulted in inhibition of the enzyme that was competitive with respect to NADH. Positive chain length effects were observed in the second-order rate constants for inactivation and in the 6-fold better binding of N-heptylmaleimide as compared to that for N-ethylmaleimide. It is suggested that the nonpolar interactions stabilizing the 1,4-dihydronicotinamide molety of the reduced coenzyme also facilitate the initial binding of N-alkylmaleimides. © 1990.
引用
收藏
页码:84 / 88
页数:5
相关论文
共 18 条
[11]  
KAHN DW, 1986, J BIOL CHEM, V261, P6016
[12]  
Lwoff A, 1937, PROC R SOC SER B-BIO, V122, P352
[13]   INTERACTIONS OF INHIBITORS AT COENZYME BINDING-SITE OF 6-PHOSPHOGLUCONATE DEHYDROGENASE [J].
NOBLE, C ;
ANDERSON, BM .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1977, 178 (01) :26-33
[14]   INACTIVATION OF RAT OVARIAN 20-ALPHA-HYDROXYSTEROID DEHYDROGENASE BY N-ALKYLMALEIMIDES [J].
PONGSAWASDI, P ;
ANDERSON, BM .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1984, 233 (02) :481-488
[15]  
Schlenk F, 1942, J BIOL CHEM, V143, P295
[16]  
TELEPNEVA VI, 1987, BIOCHEM INT, V14, P903
[17]   KINETIC-STUDIES OF HEMOPHILUS-INFLUENZAE MALATE-DEHYDROGENASE [J].
YOON, H ;
ANDERSON, BM .
BIOCHIMICA ET BIOPHYSICA ACTA, 1988, 955 (01) :10-18
[18]   KINETIC-STUDIES OF HEMOPHILUS-INFLUENZAE 6-PHOSPHOGLUCONATE DEHYDROGENASE [J].
YOON, HJ ;
ANDERSON, CD ;
ANDERSON, BM .
BIOCHIMICA ET BIOPHYSICA ACTA, 1989, 994 (01) :75-80