Enzymatic H-transfer requires vibration-driven extreme tunneling

Jaswir Basran; Michael J. Sutcliffe; Nigel S. Scrutton

doi:10.1021/bi982719d

Enzymatic H-transfer requires vibration-driven extreme tunneling

Jaswir Basran, Michael J. Sutcliffe, Nigel S. Scrutton

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

Abstract

Enzymatic breakage of the substrate C-H bond by Methylophilus methyltrophus (sp. W3A1) methylamine dehydrogenase (MADH) has been studied by stopped-flow spectroscopy. The rate of reduction of the tryptophan tryptophylquinone (TTQ) cofactor has a large kinetic isotope effect (KIE = 16.8 :k 0.5), and the KIE is independent of temperature. Analysis of the temperature dependence of C-H bond breakage revealed that extreme (ground state) quantum tunneling is responsible for the transfer of the hydrogen nucleus. Reaction rates are strongly dependent on temperature, indicating thermally induced, vibrational motion drives the H-transfer reaction. The data provide direct experimental evidence for enzymatic bond breakage by extreme tunneling driven by vibrational motion of the protein scaffold. The results demonstrate that classical transition state theory and its tunneling derivatives do not adequately describe this enzymatic reaction.

Original language	English
Pages (from-to)	3218-3222
Number of pages	4
Journal	Biochemistry
Volume	38
Issue number	10
DOIs	https://doi.org/10.1021/bi982719d
Publication status	Published - 9 Mar 1999

Access to Document

10.1021/bi982719d

Cite this

@article{9158d8f8fb8c4c559c6f68885102de77,

title = "Enzymatic H-transfer requires vibration-driven extreme tunneling",

abstract = "Enzymatic breakage of the substrate C-H bond by Methylophilus methyltrophus (sp. W3A1) methylamine dehydrogenase (MADH) has been studied by stopped-flow spectroscopy. The rate of reduction of the tryptophan tryptophylquinone (TTQ) cofactor has a large kinetic isotope effect (KIE = 16.8 :k 0.5), and the KIE is independent of temperature. Analysis of the temperature dependence of C-H bond breakage revealed that extreme (ground state) quantum tunneling is responsible for the transfer of the hydrogen nucleus. Reaction rates are strongly dependent on temperature, indicating thermally induced, vibrational motion drives the H-transfer reaction. The data provide direct experimental evidence for enzymatic bond breakage by extreme tunneling driven by vibrational motion of the protein scaffold. The results demonstrate that classical transition state theory and its tunneling derivatives do not adequately describe this enzymatic reaction.",

author = "Jaswir Basran and Sutcliffe, {Michael J.} and Scrutton, {Nigel S.}",

year = "1999",

month = mar,

day = "9",

doi = "10.1021/bi982719d",

language = "English",

volume = "38",

pages = "3218--3222",

journal = "Biochemistry",

issn = "0006-2960",

publisher = "American Chemical Society",

number = "10",

}

TY - JOUR

T1 - Enzymatic H-transfer requires vibration-driven extreme tunneling

AU - Basran, Jaswir

AU - Sutcliffe, Michael J.

AU - Scrutton, Nigel S.

PY - 1999/3/9

Y1 - 1999/3/9

N2 - Enzymatic breakage of the substrate C-H bond by Methylophilus methyltrophus (sp. W3A1) methylamine dehydrogenase (MADH) has been studied by stopped-flow spectroscopy. The rate of reduction of the tryptophan tryptophylquinone (TTQ) cofactor has a large kinetic isotope effect (KIE = 16.8 :k 0.5), and the KIE is independent of temperature. Analysis of the temperature dependence of C-H bond breakage revealed that extreme (ground state) quantum tunneling is responsible for the transfer of the hydrogen nucleus. Reaction rates are strongly dependent on temperature, indicating thermally induced, vibrational motion drives the H-transfer reaction. The data provide direct experimental evidence for enzymatic bond breakage by extreme tunneling driven by vibrational motion of the protein scaffold. The results demonstrate that classical transition state theory and its tunneling derivatives do not adequately describe this enzymatic reaction.

AB - Enzymatic breakage of the substrate C-H bond by Methylophilus methyltrophus (sp. W3A1) methylamine dehydrogenase (MADH) has been studied by stopped-flow spectroscopy. The rate of reduction of the tryptophan tryptophylquinone (TTQ) cofactor has a large kinetic isotope effect (KIE = 16.8 :k 0.5), and the KIE is independent of temperature. Analysis of the temperature dependence of C-H bond breakage revealed that extreme (ground state) quantum tunneling is responsible for the transfer of the hydrogen nucleus. Reaction rates are strongly dependent on temperature, indicating thermally induced, vibrational motion drives the H-transfer reaction. The data provide direct experimental evidence for enzymatic bond breakage by extreme tunneling driven by vibrational motion of the protein scaffold. The results demonstrate that classical transition state theory and its tunneling derivatives do not adequately describe this enzymatic reaction.

U2 - 10.1021/bi982719d

DO - 10.1021/bi982719d

M3 - Article

SN - 0006-2960

VL - 38

SP - 3218

EP - 3222

JO - Biochemistry

JF - Biochemistry

IS - 10

ER -

Enzymatic H-transfer requires vibration-driven extreme tunneling

Abstract

Access to Document

Fingerprint

Cite this