An Inverse Michaelis–Menten Approach for Interfacial Enzyme Kinetics

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Interfacial enzyme reactions are ubiquitous both in vivo and in technical applications, but analysis of their kinetics remains controversial. In particular, it is unclear whether conventional Michaelis–Menten theory, which requires a large excess of substrate, can be applied. Here, an extensive experimental study of the enzymatic hydrolysis of insoluble cellulose indeed showed that the conventional approach had a limited applicability. Instead we argue that, unlike bulk reactions, interfacial enzyme catalysis may reach a steady-state condition in the opposite experimental limit, where the concentration of enzyme far exceeded the molar concentration of accessible surface sites. Under this condition, an “inverse Michaelis–Menten equation”, where the roles of enzyme and substrate had been swapped, proved to be readily applicable. We suggest that this inverted approach provides a general tool for kinetic analyses of interfacial enzyme reactions and that its analogy to established theory provides a bridge to the accumulated understanding of steady-state enzyme kinetics. Finally, we show that the ratio of parameters from conventional and inverted Michaelis–Menten analysis reveals the density of enzyme attack sites on the substrate surface as probed by one specific enzyme. This density, which is an analogue to a molar substrate concentration for interfacial reactions, was shown to vary strongly even among related enzymes. This difference reflects how the enzyme discriminates between local differences in surface structure on the substrate.
OriginalsprogEngelsk
TidsskriftACS Catalysis
Vol/bind7
Udgave nummer7
Sider (fra-til)4904–4914
Antal sider11
ISSN2155-5435
DOI
StatusUdgivet - 2017

Emneord

  • Cellulase
  • Cellulose
  • Enzyme
  • Enzyme kinetics
  • heterogeneous catalysis
  • Michaelis–Menten
  • Protein engineering
  • Steady-state
  • Surface-reactions

Citer dette

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title = "An Inverse Michaelis–Menten Approach for Interfacial Enzyme Kinetics",
abstract = "Interfacial enzyme reactions are ubiquitous both in vivo and in technical applications, but analysis of their kinetics remains controversial. In particular, it is unclear whether conventional Michaelis–Menten theory, which requires a large excess of substrate, can be applied. Here, an extensive experimental study of the enzymatic hydrolysis of insoluble cellulose indeed showed that the conventional approach had a limited applicability. Instead we argue that, unlike bulk reactions, interfacial enzyme catalysis may reach a steady-state condition in the opposite experimental limit, where the concentration of enzyme far exceeded the molar concentration of accessible surface sites. Under this condition, an “inverse Michaelis–Menten equation”, where the roles of enzyme and substrate had been swapped, proved to be readily applicable. We suggest that this inverted approach provides a general tool for kinetic analyses of interfacial enzyme reactions and that its analogy to established theory provides a bridge to the accumulated understanding of steady-state enzyme kinetics. Finally, we show that the ratio of parameters from conventional and inverted Michaelis–Menten analysis reveals the density of enzyme attack sites on the substrate surface as probed by one specific enzyme. This density, which is an analogue to a molar substrate concentration for interfacial reactions, was shown to vary strongly even among related enzymes. This difference reflects how the enzyme discriminates between local differences in surface structure on the substrate.",
keywords = "cellulase, cellulose, enzyme kinetics, heterogeneous catalysis, enzyme, Michaelis−Menten, protein engineering, steady-state, surface-reactions, Cellulase, Cellulose, Enzyme, Enzyme kinetics, heterogeneous catalysis, Michaelis–Menten, Protein engineering, Steady-state, Surface-reactions",
author = "Jeppe Kari and Morten Andersen and Kim Borch and Peter Westh",
year = "2017",
doi = "10.1021/acscatal.7b00838",
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pages = "4904–4914",
journal = "ACS Catalysis",
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publisher = "American Chemical Society",
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An Inverse Michaelis–Menten Approach for Interfacial Enzyme Kinetics. / Kari, Jeppe; Andersen, Morten; Borch, Kim; Westh, Peter.

I: ACS Catalysis, Bind 7, Nr. 7, 2017, s. 4904–4914.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - An Inverse Michaelis–Menten Approach for Interfacial Enzyme Kinetics

AU - Kari, Jeppe

AU - Andersen, Morten

AU - Borch, Kim

AU - Westh, Peter

PY - 2017

Y1 - 2017

N2 - Interfacial enzyme reactions are ubiquitous both in vivo and in technical applications, but analysis of their kinetics remains controversial. In particular, it is unclear whether conventional Michaelis–Menten theory, which requires a large excess of substrate, can be applied. Here, an extensive experimental study of the enzymatic hydrolysis of insoluble cellulose indeed showed that the conventional approach had a limited applicability. Instead we argue that, unlike bulk reactions, interfacial enzyme catalysis may reach a steady-state condition in the opposite experimental limit, where the concentration of enzyme far exceeded the molar concentration of accessible surface sites. Under this condition, an “inverse Michaelis–Menten equation”, where the roles of enzyme and substrate had been swapped, proved to be readily applicable. We suggest that this inverted approach provides a general tool for kinetic analyses of interfacial enzyme reactions and that its analogy to established theory provides a bridge to the accumulated understanding of steady-state enzyme kinetics. Finally, we show that the ratio of parameters from conventional and inverted Michaelis–Menten analysis reveals the density of enzyme attack sites on the substrate surface as probed by one specific enzyme. This density, which is an analogue to a molar substrate concentration for interfacial reactions, was shown to vary strongly even among related enzymes. This difference reflects how the enzyme discriminates between local differences in surface structure on the substrate.

AB - Interfacial enzyme reactions are ubiquitous both in vivo and in technical applications, but analysis of their kinetics remains controversial. In particular, it is unclear whether conventional Michaelis–Menten theory, which requires a large excess of substrate, can be applied. Here, an extensive experimental study of the enzymatic hydrolysis of insoluble cellulose indeed showed that the conventional approach had a limited applicability. Instead we argue that, unlike bulk reactions, interfacial enzyme catalysis may reach a steady-state condition in the opposite experimental limit, where the concentration of enzyme far exceeded the molar concentration of accessible surface sites. Under this condition, an “inverse Michaelis–Menten equation”, where the roles of enzyme and substrate had been swapped, proved to be readily applicable. We suggest that this inverted approach provides a general tool for kinetic analyses of interfacial enzyme reactions and that its analogy to established theory provides a bridge to the accumulated understanding of steady-state enzyme kinetics. Finally, we show that the ratio of parameters from conventional and inverted Michaelis–Menten analysis reveals the density of enzyme attack sites on the substrate surface as probed by one specific enzyme. This density, which is an analogue to a molar substrate concentration for interfacial reactions, was shown to vary strongly even among related enzymes. This difference reflects how the enzyme discriminates between local differences in surface structure on the substrate.

KW - cellulase

KW - cellulose

KW - enzyme kinetics

KW - heterogeneous catalysis

KW - enzyme

KW - Michaelis−Menten

KW - protein engineering

KW - steady-state

KW - surface-reactions

KW - Cellulase

KW - Cellulose

KW - Enzyme

KW - Enzyme kinetics

KW - heterogeneous catalysis

KW - Michaelis–Menten

KW - Protein engineering

KW - Steady-state

KW - Surface-reactions

U2 - 10.1021/acscatal.7b00838

DO - 10.1021/acscatal.7b00838

M3 - Journal article

VL - 7

SP - 4904

EP - 4914

JO - ACS Catalysis

JF - ACS Catalysis

SN - 2155-5435

IS - 7

ER -