scholarly journals A study of the ionic properties of the essential histidine residue of yeast alcohol dehydrogenase in complexes of the enzyme with its coenzymes and substrates

1977 ◽  
Vol 161 (1) ◽  
pp. 73-82 ◽  
Author(s):  
C J Dickenson ◽  
F M Dickinson
Keyword(s):  
Alcohol Dehydrogenase ◽  
Initial Rate ◽  
Dissociation Constants ◽  
Ternary Complexes ◽  
Histidine Residue ◽  
Mechanism Of Formation ◽  
Binary And Ternary Complexes ◽  
Yeast Alcohol Dehydrogenase ◽  
Ph Range

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.

scholarly journals A study of the oxidation of butan-1-ol and propan-2-ol by nicotinamide-adenine dinucleotide catalysed by yeast alcohol dehydrogenase.

1975 ◽  
Vol 147 (3) ◽  
pp. 541-547 ◽  
Author(s):  
C J Dickenson ◽  
F M Dickinson
Keyword(s):  
Alcohol Dehydrogenase ◽  
Ternary Complexes ◽  
Kinetics Of Oxidation ◽  
Yeast Alcohol Dehydrogenase ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Ph Range ◽  
Rate Limiting ◽  
Kinetics Of ◽  
Flow Experiments

1. The kinetics of oxidation of butan-1-ol and propan-2-ol by NAD+, catalysed by yeast alcohol dehydrogenase, were studied at 25 degrees C from pH 5.5 to 10, and at pH 7.05 from 14 degrees to 44 degrees C, 2. Under all conditions studied the results are consistent with a mechanism whereby some dissociation of coenzyme from the active enzyme-NAD+-alcohol ternary complexes occurs, and the mechanism is therefore not strictly compulsory order. 3. A primary 2H isotopic effect on the maximum rates of oxidation of [1-2H2]butan-1-ol and [2H7]propan-2-ol was found at 25 degrees C over the pH range 5.5-10. Further, in stopped-flow experiments at pH 7.05 and 25 degrees C, there was no transient formation of NADH in the oxidation of butan-1-ol and propan-2-ol. The principal rate-limiting step in the oxidation of dependence on pH of the maximum rates of oxidation of butan-1-ol and propan-2-ol is consisten with the possibility that histidine and cysteine residues may affect or control catalysis.

Kinetic effect of some aliphatic amines on yeast alcohol dehydrogenase

1976 ◽  
Vol 54 (5) ◽  
pp. 432-437
Author(s):  
M. J. Dove ◽  
C. S. Tsai
Keyword(s):  
Alcohol Dehydrogenase ◽  
Ethanol Oxidation ◽  
Initial Rate ◽  
Relative Concentration ◽  
Aliphatic Amines ◽  
Kinetic Effect ◽  
Yeast Alcohol Dehydrogenase ◽  
Protonated Amines ◽  
Ph Range

Initial rate studies of ethanol oxidation catalyzed by yeast alcohol dehydrogenase (EC 1.1.1.1) were carried out in the presence of varying concentrations of aliphatic amines over the pH range from 8.0 to 10.5. Aliphatic amines either activate or inhibit the enzyme depending on whether the pH is greater or less than 9.5 suggesting that the protonated amines activate and the nonprotonated amines inhibit the enzyme. Aliphatic amines activate yeast alcohol dehydrogenase by decreasing Kb while they inhibit the enzyme by increasing both Ka and Kia. When both protonated and nonprotonated amines are present in solution, either overall activation or inhibition will be observed depending on the relative concentration of the two amine species.

scholarly journals A study of the pH- and temperature-dependence of the reactions of yeast alcohol dehydrogenase with ethanol, acetaldehyde and butyraldehyde as substrates

1975 ◽  
Vol 147 (2) ◽  
pp. 303-311 ◽  
Author(s):  
C J Dickenson ◽  
F M Dickinson
Keyword(s):  
Alcohol Dehydrogenase ◽  
Temperature Dependence ◽  
Initial Rate ◽  
British Library ◽  
Yeast Alcohol Dehydrogenase ◽  
Wide Range ◽  
Mechanism Of Catalysis ◽  
Ph Range ◽  
Kinetics Of ◽  
Kinetics Of Reduction

The kinetics of ethanol oxidation by NAD+, and acetaldehyde and butyraldehyde reduction by NADH, catalysed by yeast alcohol dehydrogenase, were studied in the pH range 4.9--9.9 at 25 degrees C and in the temperature range 14.8--43.5 degrees C at pH 7.05. The kinetics of reduction of acetaldehyde by [4A-2H]NADH at pH 7.05 and pH 8.9 at 25 degrees C were also studied. The results of the kinetic experiments indicate that the mechanism of catalysis, previously proposed on the basis of studies at pH 7.05 and 25 degrees C (Dickinson & Monger, 1973), applies over the wide range of conditions now tested. Values of some of the initial-rate parameters obtained were used to deduce information about the pH- and temperature-dependence of the specific rates of combination of enzyme and coenzymes and of the dissociation of the enzyme--coenzyme compounds. Primary and secondary plots of initial-rate data are deposited as Supplementary Publication SUP 50043 (20 pages) with the British Library (Lending Division), Boston Spa, Wetherby, Yorks. LS23 7BQ, U.K., from whom copies may be obtained under the terms indicated in Biochem. J. (1975) 145, 5.

scholarly journals Role of the essential thiol groups of yeast alcohol dehydrogenase

1972 ◽  
Vol 126 (1) ◽  
pp. 133-138 ◽  
Author(s):  
F. M. Dickinson
Keyword(s):  
Alcohol Dehydrogenase ◽  
Dissociation Constant ◽  
Binding Capacity ◽  
Ternary Complexes ◽  
Native Enzyme ◽  
Thiol Groups ◽  
Yeast Alcohol Dehydrogenase

1. Yeast alcohol dehydrogenase inactivated by reaction with iodoacetamide retains 85% of the original NADH-binding capacity as measured under conditions of saturating coenzyme concentration. 2. The dissociation constant of the enzyme–NADH complex is unaffected by inactivation of the enzyme with iodoacetamide, and the affinity of the enzyme for NAD+ and pyridine-3-aldehyde–adenine dinucleotide (PAAD+) appears to be similarly unaffected. 3. Enzyme inactivated with iodoacetamide has lost the ability to form normal ternary complexes of the type enzyme–NADH–acetamide and enzyme–PAAD+–hydroxylamine that are characteristic of the native enzyme.

scholarly journals The reactions of 1,10-phenanthroline with yeast alcohol dehydrogenase

1977 ◽  
Vol 167 (1) ◽  
pp. 237-244 ◽  
Author(s):  
F M Dickinson ◽  
S Berrieman
Keyword(s):  
Alcohol Dehydrogenase ◽  
Complete Recovery ◽  
Ternary Complexes ◽  
Second Step ◽  
Two Stage ◽  
Reversible Process ◽  
Structural Role ◽  
Yeast Alcohol Dehydrogenase ◽  
Stage Process

Freshly prepared samples of yeast alcohol dehydrogenase (EC 1.1.1.1) were inhibited by 1,10-phenanthroline at pH 7.0 and 0 degrees C in a two-stage process. The first step appeared to be slowly established, but was rendered reversible by removal of reagent or by addition of excess Zn2+ ions. The second step was irreversible and was associated with the dissociation of the tetrameric enzyme. The presence of saturating concentrations of NAD+ or NADH promoted and enhanced inhibition by the slowly established reversible process, but prevented dissociation of the enzyme. For the incubation mixtures containing NAD+, removal of the 1,10-phenanthroline resulted in virtually complete recovery of activity, whereas, for the incubation mixtures containing NADH, removal of the reagent gave only partial re-activation. The presence of NAD+ and pyrazole, or NADH and acetamide, in incubation mixtures with the enzyme gave rise to ternary complexes that gave protection against both forms of inactivation by 1,10-phenanthroline. The results support the view that at least some of the Zn2+ ions associated with yeast alcohol dehydrogenase have a catalytic, as opposed to a purely structural, role.

Binary and ternary complexes of FLNa-Ig21 with cytosolic tails of αMß2 integrin reveal dual role of filamin mediated regulation

2021 ◽  
Vol 1865 (12) ◽  
pp. 130005
Author(s):  
Lewis Lu Zhiping ◽  
Li-Teng Ong ◽  
Deepak Chatterjee ◽  
Suet-Mien Tan ◽  
Surajit Bhattacharjya
Keyword(s):  
Ternary Complexes ◽  
Dual Role ◽  
Binary And Ternary Complexes

scholarly journals Kinetics and reaction mechanism of yeast alcohol dehydrogenase with long-chain primary alcohols

1976 ◽  
Vol 157 (1) ◽  
pp. 15-22 ◽  
Author(s):  
W Schöpp ◽  
H Aurich
Keyword(s):  
Alcohol Dehydrogenase ◽  
Dissociation Constants ◽  
Kinetic Studies ◽  
Random Order ◽  
Primary Alcohols ◽  
Yeast Alcohol Dehydrogenase ◽  
Kinetic Coefficients ◽  
Non Linear ◽  
High Concentrations ◽  
Long Chain

Kinetic studies of yeast alcohol dehydrogenase with NAD+ and ethanol, hexanol or decanol as substrates invariably result in non-linear Lineweaver-Burk plots if the alcohol is the variable substrate. The kinetic coefficients determined from secondary plots are consistent with an ‘equilibrium random-order‘ mechanism for extremely low alcohol concentrations and for all alcohols, the transformation of the ternary complexes being the rate-limiting step of the reaction. This mechanism also applies to long-chain substrates at high concentrations, whereas the rate of the ethanol-NAD+ reaction at high ethanol concentrations is determined by the dissociation of the enzyme-NADH complex. The dissociation constants for the enzyme-NAD+ complex and for the enzyme-alcohol complexes obtained from the kinetic quotients satisfactorily correspond to the dissociation constants obtained by use of other techniques. It is suggested that the non-linear curves may be attributed to a structural change in the enzyme itself, caused by the alcohol.

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