The secondary α-deuterium isotope effect at the site of the enzyme-catalyzed cis-trans isomerization of maleylacetone. Mechanistic implications

1999 ◽  
Vol 77 (5-6) ◽  
pp. 557-564
Author(s):  
Michael S Finnin ◽  
Stanley Seltzer
Keyword(s):  
Isotope Effect ◽  
Nucleophilic Addition ◽  
Single Bond ◽  
Glutathione System ◽  
Competitive Reaction ◽  
Deuterium Isotope Effect ◽  
Detailed Mechanism ◽  
H Nmr ◽  
Trans Isomerization ◽  
Isomerization Mechanism

An equal mixture of monodeuterated isotopomers of maleylacetone, viz., 4-hydroxy-6-oxo-2,4-heptadienoic-2-d1 acid (1) and 4-hydroxy-6-oxo-2,4-heptadienoic-3-d1 acid (2) was synthesized and subjected to catalyzed cis-trans isomerization by the maleylacetoacetate cis-trans isomerase-glutathione system. These studies were designed to probe the detailed mechanism of enzyme-catalyzed cis-trans isomerization about the C-2—C-3 bond of the substrate. In the competitive reaction, 2 accumulates with respect to 1 at high extent of reaction. 1H NMR analysis indicates that 1 reacts 15% faster than 2 in line with a nucleophilic addition mechanism at C-2 rather than a conjugate addition mechanism at C-2 and C-3, to convert the C-2—C-3 double bond to a single bond to allow facile internal rotation.Key words: enzyme-catalyzed cis-trans isomerization, secondary α-deuterium isotope effect, maleylacetoacetate cis-trans isomerase, cis-trans isomerization mechanism.

Hydrolysis of α-bromoisobutyrate ion in water

1967 ◽  
Vol 45 (18) ◽  
pp. 2071-2077 ◽  
Author(s):  
B. N. Hendy ◽  
W. A. Redmond ◽  
R. E. Robertson
Keyword(s):  
Temperature Dependence ◽  
Isotope Effect ◽  
Deuterium Isotope Effect ◽  
Detailed Mechanism ◽  
Temperature Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

The temperature dependence of the rate of hydrolysis of α-bromoisobutyrate ion in water was determined over a temperature range 9–37 °C. From these data corresponding values of ΔH≠, ΔS≠, and ΔCP≠ have been derived. The implication of these terms, together with corresponding data for hydrolysis in D2O and for the secondary deuterium isotope effect from the hydrolysis of (CD3)2CBrCOO−, provide a basis for reexamining the detailed mechanism with particular reference to accompanying solvent reorganization.

Remote deuterium isotope effect in the nucleophilic-addition of BH−4 to cis 2,6-diphenyl 4-piperidone : anisotropy of the steric isotope effect.

1977 ◽  
Vol 18 (2) ◽  
pp. 199-200
Author(s):  
R. Durand ◽  
P. Geneste ◽  
G. Lamaty ◽  
J.P. Roque
Keyword(s):  
Isotope Effect ◽  
Nucleophilic Addition ◽  
Deuterium Isotope Effect

scholarly journals alpha-Hydroxylation of fatty acids in brain. Substrate specificity and deuterium isotope effect.

1977 ◽  
Vol 252 (15) ◽  
pp. 5206-5210
Author(s):  
S Murad ◽  
R H Chen ◽  
Y Kishimoto
Keyword(s):  
Fatty Acids ◽  
Substrate Specificity ◽  
Isotope Effect ◽  
Deuterium Isotope Effect

ChemInform Abstract: SOLVENT DEUTERIUM ISOTOPE EFFECT ON HYDROLYSIS OF BORIC ACID

1978 ◽  
Vol 9 (26) ◽  
Author(s):  
M. MAEDA ◽  
Y. SUNAOKA ◽  
H. KAKIHANA
Keyword(s):  
Boric Acid ◽  
Isotope Effect ◽  
Deuterium Isotope Effect ◽  
Hydrolysis Of

The Secondary β-Deuterium Isotope Effect and the Cage Effect in the Thermal Decomposition of Azobis-α-phenylethane1

1966 ◽  
Vol 88 (16) ◽  
pp. 3775-3781 ◽  
Author(s):  
Stanley Seltzer ◽  
Edwin J. Hamilton
Keyword(s):  
Thermal Decomposition ◽  
Isotope Effect ◽  
Cage Effect ◽  
Deuterium Isotope Effect

Partial kinetic ‘resolution’ resulting from a deuterium isotope effect

1991 ◽  
Vol 0 (12) ◽  
pp. 801-802 ◽  
Author(s):  
Panayiotis Anastasis ◽  
Raymond Duffin ◽  
Christopher Gilmore ◽  
Karl Overton
Keyword(s):  
Isotope Effect ◽  
Kinetic Resolution ◽  
Deuterium Isotope Effect

ChemInform Abstract: EXCESS ENTHALPY OF (TETRACHLOROMETHANE + 2-PROPANONE): DEUTERIUM ISOTOPE EFFECT

1985 ◽  
Vol 16 (17) ◽  
Author(s):  
E. KENYON-BLAIR ◽  
K. W. MORCOM
Keyword(s):  
Isotope Effect ◽  
Excess Enthalpy ◽  
Deuterium Isotope Effect
Sign in / Sign up

Export Citation Format

Share Document