Role of histidine in molecule of pea alcohol dehydrogenase

1982 ◽  
Vol 47 (5) ◽  
pp. 1408-1413 ◽  
Author(s):  
Noemi Čeřovská ◽  
Jana Barthová ◽  
Sylva Leblová

Alcohol dehydrogenase (E.C.1.1.1.1) from germinating pea seedlings was modified by treatment with diethyl pyrocarbonate. The inactivation rate is proportional to the molar concentration of the modifying agent; the inactivation was almost complete in fifty minutes at a diethyl pyrocarbonate concentration of 5 . 10-6 mol/l. The histidine content calculated from the absorbance difference at 240 nm was 3.43 residues per molecule of native and 4.75 residues per molecule of demetalized enzyme. A correlation of the absorbance difference at 240 nm with a 100% loss of enzymatic activity shows that 1.22 histidine residue is essential for the activity of alcohol dehydrogenase. The dependence of the inactivation rate constant on the pH of the medium indicates that the treatment of pea alcohol dehydrogenase with diethyl pyrocarbonate results in the modification of one group only with a pK of 7.1, well corresponding to the imidazole group of histidine. The enzyme is partially protected against inactivation by NADH at a concentration close to the Michaelis constant for NADH. The treatment of the ethoxyformylated enzyme with hydroxylamine followed by dialysis restored the activity of pea alcohol dehydrogenase by 88%.

1991 ◽  
Vol 278 (2) ◽  
pp. 595-599 ◽  
Author(s):  
N Hirano ◽  
T Ichiba ◽  
A Hachimori

Treatment of the inorganic pyrophosphatase from thermophilic bacterium PS-3 with diethyl pyrocarbonate resulted in the almost complete loss of its activity, which followed pseudo-first-order kinetics. The presence of Mg2+ prevented the inactivation. Enzyme inactivated with diethyl pyrocarbonate was re-activated by hydroxylamine. The inactivation parallelled the amount of modified histidine residue, and a plot of the activity remaining against the amount of modified histidine residue suggested that the modification of one of two histidine residues totally inactivated the enzyme. The site involved was found to be located in a single lysyl endopeptidase-digest peptide derived from the ethoxy[14C]carbonylated enzyme. Amino acid analysis and sequence analysis of the peptide revealed that it comprised residues 96-119 of the inorganic pyrophosphatase from thermophilic bacterium PS-3. These results, when compared with those reported for the Escherichia coli and yeast enzymes, imply that His-118 of the inorganic pyrophosphatase from thermophilic bacterium PS-3 is located near the Mg(2+)-binding site and thus affects the binding of Mg2+.


1980 ◽  
Vol 45 (5) ◽  
pp. 1608-1615 ◽  
Author(s):  
Jana Barthová ◽  
Pavla Plachá ◽  
Sylva Leblová

Lactate dehydrogenase (EC 1.1.1.27) was isolated from soybean seedlings (Glycine max. L.) by affinity chromatography on an AMP-Sepharose 4B column. The enzyme obtained was inactivated by treatment with diethyl pyrocarbonate; the inactivation rate was proportional to the molar ratio of the enzyme to the reagent. The plot of the inactivation rate versus pH shows that of all the functional groups of the protein the imidazole groups of histidine only were modified by diethyl pyrocarbonate. By this procedure 20 histidine residues were ethoxyformylated in the molecule of soybean lactate dehydrogenase yet 8 only, i.e. two in every subunit were essential for thae activity of the enzyme. A comparison of the effect of diethyl pyrocarbonate on the lactate dehydrogenase apoenzyme with its effect on the binary complexes of the enzyme with coenzymes or on ternary complexes with its both substrates permits the conclusion that histidine is involved not only in the proton transfer during the redox reaction but also in the coenzyme-binding site.


1975 ◽  
Vol 145 (3) ◽  
pp. 581-590 ◽  
Author(s):  
V Leskovac ◽  
D Pavkov-Peričin

1. Yeast alcohol dehydrogenase (EC 1.1.1.1) is inhibited by stoicheiometric concentrations of diethyl pyrocarbonate. The inhibition is due to the acylation of a single histidine residue/monomer (mol.wt. 36000). 2. Alcohol dehydrogenase is also inhibited by stoicheiometric amounts of 5,5′-dithiobis-(2-nitrobenzoate), owing to the modification of a single cysteine residue/monomer. 3. Native alcohol dehydrogenase binds two molecules of reduced coenzyme/molecule of enzyme (mol.wt. 144000). 4. Modification of a single histidine residue/monomer by treatment with diethyl pyrocarbonate prevents the binding of acetamide in the ternary complex, enzyme-NADH-acetamede, but does not prevent the binding of NADH to the enzyme. 5. Modification of a single cysteine residue/monomer does not prevent the binding of acetamide to the ternary complex. After the modification of two thiol groups/monomer by treatment with 5,5′-dithiobis-(2-nitrobenzoate), the capacity of enzyme to bind coenzyme in the ternary complex was virtually abolished. 6. From the results presented in this paper we conclude that at least one histidine and one cysteine residue are closely associated in the substrate-binding site of alcohol dehydrogenase.


1977 ◽  
Vol 161 (1) ◽  
pp. 73-82 ◽  
Author(s):  
C J Dickenson ◽  
F M Dickinson

1. Initial-rate studies of the reduction of acetaldehyde by NADH, catalysed by yeast alcohol dehydrogenase, were performed at pH 4.9 and 9.9, in various buffers, at 25 degrees C. The results are discussed in terms of the mechanism previously proposed for the pH range 5.9-8.9 [Dickenson & Dickinson (1975) Biochem. J. 147, 303-311]. 2. Acetaldehyde forms a u.v.-absorbing complex with glycine. This was shown not to affect the results of kinetic experiments under the conditions used in this and earlier work. 3. The variation with pH of the dissociation constant for the enzyme-NADH complex, calculated from the initial-rate data, indicates that the enzyme possesses a group with pK7.1 in the free enzyme and pK8.7 in the complex. 4. The pH-dependences of the second-order rate constants for inactivation of the enzyme by diethyl pyrocarbonate were determined for the free enzymes (pK7.1), the enzyme-NAD+ complex (pK approx. 7.1) and the enzyme-NADH complex (pK approx. 8.4). The essential histidine residue may therefore be the group involved in formation and dissociation of the enzyme-NADH complex. 5. Estimates of the rate constant for reaction of acetaldehyde with the enzyme-NADH complex indicate that acetaldehyde may combine only when the essential histidine residue is protonated. The dissociation constants for butan-1-ol and propan-2-ol, calculated on the basis of earlier kinetic data, are, however, independent of pH. 6. The results obtained are discussed in relation to the role of the essential histidine residue in the mechanism of formation of binary and ternary complexes of the enzyme with its coenzymes and substrates.


1980 ◽  
Vol 45 (5) ◽  
pp. 1601-1607 ◽  
Author(s):  
Marie Stiborová ◽  
Sylva Leblová

Iodoacetate inactivates rape alcohol dehydrogenase (ADH, EC 1.1.1.1). The inactivation rate follows the kinetics of the first order, is pH-dependent, and decreases below pH 7.5. Besides irreversible alkylation of the sulfhydryl groups of the enzyme iodoacetate also forms a reversible complex with rape ADH. The coenzyme (NAD) and its analogs (ATP, ADP, AMP) competitively protect the enzyme against alkylation; o-phenanthroline also protects the enzyme against alkylation yet noncompetitively with respect to iodoacetate. Imidazole and o-phenanthroline compete with one another for binding to the protein molecule of rape ADH. Whereas o-phenanthroline decreases the inactivation rate imidazole increases the rate of iodoacetate inactivation.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 216
Author(s):  
Alanna C. Tseng ◽  
Vivek R. Nerurkar ◽  
Kabi R. Neupane ◽  
Helmut Kae ◽  
Pakieli H. Kaufusi

West Nile virus (WNV) nonstructural protein 3 (NS3) harbors the viral triphosphatase and helicase for viral RNA synthesis and, together with NS2B, constitutes the protease responsible for polyprotein processing. NS3 is a soluble protein, but it is localized to specialized compartments at the rough endoplasmic reticulum (RER), where its enzymatic functions are essential for virus replication. However, the mechanistic details behind the recruitment of NS3 from the cytoplasm to the RER have not yet been fully elucidated. In this study, we employed immunofluorescence and biochemical assays to demonstrate that NS3, when expressed individually and when cleaved from the viral polyprotein, is localized exclusively to the cytoplasm. Furthermore, NS3 appeared to be peripherally recruited to the RER and proteolytically active when NS2B was provided in trans. Thus, we provide evidence for a potential additional role for NS2B in not only serving as the cofactor for the NS3 protease, but also in recruiting NS3 from the cytoplasm to the RER for proper enzymatic activity. Results from our study suggest that targeting the interaction between NS2B and NS3 in disrupting the NS3 ER localization may be an attractive avenue for antiviral drug discovery.


1959 ◽  
Vol 234 (10) ◽  
pp. 2621-2626 ◽  
Author(s):  
Bert L. Vallee ◽  
Robert J.P. Williams ◽  
Frederic L. Hoch

2015 ◽  
pp. mvv108 ◽  
Author(s):  
Shouji Takahashi ◽  
Kozue Shimada ◽  
Shunsuke Nozawa ◽  
Masaru Goto ◽  
Katsumasa Abe ◽  
...  

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