Kinetic Solvent Isotope Effect: A Simple, Multipurpose Physical Chemistry Experiment

Seoud, Omar A. El; Bazito, Reinaldo C.; Sumodjo, Paulo Teng An

doi:10.1021/ed074p562

Cited by 16 publications

(13 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These computational results clearly support a concerted, one-water molecule transition state, which is contrary to conventional thought that at least two water molecules are structurally involved in the transition state. 31,32 Computational results suggest that the entropic cost is too great for the meager energy payoff of adding additional water molecules in the transition state.…”

Section: Computational Resultsmentioning

confidence: 99%

Detailed thermodynamic analysis of the activation parameters for the simple hydrolysis of acetic anhydride in the acetonitrile/water cosolvent system

et al. 2017

View full text Add to dashboard Cite

A detailed thermodynamic analysis of the activation parameters for the simple hydrolysis of acetic anhydride in an acetonitrile/water cosolvent system is presented. The activation parameters are obtained using regression analyses of the Eyring rate equation under iso-mole fraction and isodielectric conditions. The iso-mole fraction Eyring plots are linear, indicating the activation enthalpy and entropy are both temperature independent under these conditions. However, the isodielectric Eyring plots are non-linear, and the analysis shows both the activation entropy and activation enthalpy are strongly temperature dependent under isodielectric conditions. The thermodynamic analysis is complemented by linear solvent energy analysis and computational studies of possible transition structures, the latter showing that a concerted six-member ring structure with a single water molecule is the likely transition state.

show abstract

Section: Computational Resultsmentioning

confidence: 99%

Detailed thermodynamic analysis of the activation parameters for the simple hydrolysis of acetic anhydride in the acetonitrile/water cosolvent system

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This is readily explained by the fact that the molar volume of butyric anhydride is 1.73 times larger than that of acetic anhydride. Additionally, the hydrolysis of the latter (a model acyl transfer reaction) is 3.02 faster than that of butyric anhydride 50, 51…”

Section: Resultsmentioning

confidence: 99%

“…Additionally, the hydrolysis of the latter (a model acyl transfer reaction) is 3.02 faster than that of butyric anhydride. [50,51] …”

Section: Functionalization Of Cellulose: Synthesis Of Esters and Mixementioning

confidence: 99%

Application of 1‐Allyl‐3‐(1‐butyl)imidazolium Chloride in the Synthesis of Cellulose Esters: Properties of the Ionic Liquid, and Comparison with Other Solvents

Fidale

Possidonio

Seoud

2009

Macromolecular Bioscience

Self Cite

View full text Add to dashboard Cite

The ionic liquid (IL), 1-allyl-3-(1-butyl)imidazolium chloride (AlBuImCl), has been synthesized and its properties determined. Increase in the temperature increased its conductivity and decreased its density, polarity, and viscosity. Microcrystalline cellulose (MCC), dissolves in this IL by heating at 80 degrees C; this did not affect its degree of polymerization, decreased its index of crystallinity (Ic), and changed in morphology after regeneration. Convenient acylation of MCC was achieved by using 50% excess anhydride at 80 degrees C, for 24 or 48 h for acetic and butyric anhydride, respectively. The composition of the mixed esters depended on the initial ratio of the anhydrides, and their order of addition.

show abstract

“…We thus performed a solvent kinetic isotope effects (SKIE) experiment to explore the proton transferring process in steps ii and iv, respectively. , Briefly, we carried out a control single-molecule experiment in D 2 O diluted buffer with other experimental conditions remaining unchanged (Figure S11). The extracted fluorescence trajectory of each HRP catalytic event in D 2 O diluted buffer was shown in Figure A,B.…”

mentioning

confidence: 99%

Single-Molecule Studies of Allosteric Inhibition of Individual Enzyme on a DNA Origami Reactor

Gao

et al. 2018

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

Unraveling the conformational changes of enzymes together with inhibition kinetics during an enzymatic reaction has great potential in screening therapeutic candidates; however, it remains challenging due to the transient nature of each intermediate step. We report our study on the noncompetitive inhibition of horseradish peroxidase with single-turnover resolution using single-molecule fluorescence microscopy. By introducing DNA origami as an addressable nanoreactor, we observe the coexistence of nascent-formed fluorescent product on both catalytic and docking sites. We further propose a single-molecule kinetic model to reveal the interplay between product generation and noncompetitive inhibition and find three distinct inhibitor releasing pathways. Moreover, the kinetic isotope effect experiment indicates a strong correlation between catalytic and docking sites, suggesting an allosteric conformational change in noncompetitive inhibition. A memory effect is also observed. This work provides an indepth understanding of the correlation between enzyme behavior and enzymatic conformational fluctuation, substrate conversion, and product releasing pathway and kinetics.

show abstract

Kinetic Solvent Isotope Effect: A Simple, Multipurpose Physical Chemistry Experiment

Cited by 16 publications

References 10 publications

Detailed thermodynamic analysis of the activation parameters for the simple hydrolysis of acetic anhydride in the acetonitrile/water cosolvent system

Detailed thermodynamic analysis of the activation parameters for the simple hydrolysis of acetic anhydride in the acetonitrile/water cosolvent system

Application of 1‐Allyl‐3‐(1‐butyl)imidazolium Chloride in the Synthesis of Cellulose Esters: Properties of the Ionic Liquid, and Comparison with Other Solvents

Single-Molecule Studies of Allosteric Inhibition of Individual Enzyme on a DNA Origami Reactor

Contact Info

Product

Resources

About