Probing active site geometry using high pressure and secondary isotope effects in an enzyme-catalysed 'deep' H-tunnelling reaction

Sam Hay; Christopher R. Pudney; Michael J. Sutcliffe; Nigel S. Scrutton

doi:10.1002/poc.1653

Probing active site geometry using high pressure and secondary isotope effects in an enzyme-catalysed 'deep' H-tunnelling reaction

Sam Hay, Christopher R. Pudney, Michael J. Sutcliffe, Nigel S. Scrutton

Research output: Contribution to journal › Article › peer-review

Abstract

We report the first study of the effects of hydrostatic pressure on α-2° KIEs for an enzyme-catalysed H-transfer reaction that occurs by 'deep' tunnelling. High pressure causes a significant decrease in the observed α-2° KIE on the presteady- state hydride transfer from NADH to FMN in the flavoprotein morphinone reductase. We have recently shown that high pressure causes a reduction in macroscopic reaction barrier width for this reaction. Using DFT vibrational analysis of a simple active site model, we posit that the decrease in α-2° KIE with pressure may arise due to a decrease in the vibrational coupling between the NADH primary (transferred) and secondary hydrogens in the 'tunnelling ready configuration', which more closely resembles the reactant state than the transition state. Copyright © 2010 John Wiley & Sons, Ltd.

Original language	English
Pages (from-to)	696-701
Number of pages	5
Journal	Journal of Physical Organic Chemistry
Volume	23
Issue number	7
DOIs	https://doi.org/10.1002/poc.1653
Publication status	Published - Jul 2010

Keywords

Flavoprotein
H-transfer
Pressure
Secondary isotope effects
Tunnelling

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title = "Probing active site geometry using high pressure and secondary isotope effects in an enzyme-catalysed 'deep' H-tunnelling reaction",

abstract = "We report the first study of the effects of hydrostatic pressure on α-2° KIEs for an enzyme-catalysed H-transfer reaction that occurs by 'deep' tunnelling. High pressure causes a significant decrease in the observed α-2° KIE on the presteady- state hydride transfer from NADH to FMN in the flavoprotein morphinone reductase. We have recently shown that high pressure causes a reduction in macroscopic reaction barrier width for this reaction. Using DFT vibrational analysis of a simple active site model, we posit that the decrease in α-2° KIE with pressure may arise due to a decrease in the vibrational coupling between the NADH primary (transferred) and secondary hydrogens in the 'tunnelling ready configuration', which more closely resembles the reactant state than the transition state. Copyright {\textcopyright} 2010 John Wiley & Sons, Ltd.",

keywords = "Flavoprotein, H-transfer, Pressure, Secondary isotope effects, Tunnelling",

author = "Sam Hay and Pudney, {Christopher R.} and Sutcliffe, {Michael J.} and Scrutton, {Nigel S.}",

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TY - JOUR

T1 - Probing active site geometry using high pressure and secondary isotope effects in an enzyme-catalysed 'deep' H-tunnelling reaction

AU - Hay, Sam

AU - Pudney, Christopher R.

AU - Sutcliffe, Michael J.

AU - Scrutton, Nigel S.

PY - 2010/7

Y1 - 2010/7

N2 - We report the first study of the effects of hydrostatic pressure on α-2° KIEs for an enzyme-catalysed H-transfer reaction that occurs by 'deep' tunnelling. High pressure causes a significant decrease in the observed α-2° KIE on the presteady- state hydride transfer from NADH to FMN in the flavoprotein morphinone reductase. We have recently shown that high pressure causes a reduction in macroscopic reaction barrier width for this reaction. Using DFT vibrational analysis of a simple active site model, we posit that the decrease in α-2° KIE with pressure may arise due to a decrease in the vibrational coupling between the NADH primary (transferred) and secondary hydrogens in the 'tunnelling ready configuration', which more closely resembles the reactant state than the transition state. Copyright © 2010 John Wiley & Sons, Ltd.

AB - We report the first study of the effects of hydrostatic pressure on α-2° KIEs for an enzyme-catalysed H-transfer reaction that occurs by 'deep' tunnelling. High pressure causes a significant decrease in the observed α-2° KIE on the presteady- state hydride transfer from NADH to FMN in the flavoprotein morphinone reductase. We have recently shown that high pressure causes a reduction in macroscopic reaction barrier width for this reaction. Using DFT vibrational analysis of a simple active site model, we posit that the decrease in α-2° KIE with pressure may arise due to a decrease in the vibrational coupling between the NADH primary (transferred) and secondary hydrogens in the 'tunnelling ready configuration', which more closely resembles the reactant state than the transition state. Copyright © 2010 John Wiley & Sons, Ltd.

KW - Flavoprotein

KW - H-transfer

KW - Pressure

KW - Secondary isotope effects

KW - Tunnelling

U2 - 10.1002/poc.1653

DO - 10.1002/poc.1653

M3 - Article

SN - 0894-3230

VL - 23

SP - 696

EP - 701

JO - Journal of Physical Organic Chemistry

JF - Journal of Physical Organic Chemistry

IS - 7

ER -

Probing active site geometry using high pressure and secondary isotope effects in an enzyme-catalysed 'deep' H-tunnelling reaction

Abstract

Keywords

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