Isotope Probing of the UDP-Apiose/UDP-Xylose Synthase Reaction: Evidence of a Mechanism via a Coupled Oxidation and Aldol Cleavage

Thomas Eixelsberger, Doroteja Horvat, Alexander Gutmann, Hansjörg Weber, Bernd Nidetzky

Publikation: Beitrag in einer FachzeitschriftArtikelForschungBegutachtung

Abstract

The C-branched sugar d-apiose (Api) is essential for plant cell-wall development. An enzyme-catalyzed decarboxylation/pyranoside ring-contraction reaction leads from UDP-α-d-glucuronic acid (UDP-GlcA) to the Api precursor UDPa-d-apiose (UDP-Api). We examined the mechanism of UDPApi/UDP-α-d-xylose synthase (UAXS) with site-selectively 2H-labeled and deoxygenated substrates. The analogue UDP-2-deoxy-GlcA, which prevents C-2/C-3 aldol cleavage as the plausible initiating step of pyranoside-to-furanoside conversion, did not give the corresponding Api product. Kinetic isotope effects (KIEs) support an UAXS mechanism in which substrate oxidation by enzyme-NAD+ and retro-aldol sugar ring-opening occur coupled in a single rate-limiting step leading to decarboxylation. Rearrangement and ring-contracting aldol addition in an open-chain intermediate then give the UDP-Api aldehyde, which is intercepted via reduction by enzyme-NADH

Originalspracheenglisch
Seiten (von - bis)2503 –2507
FachzeitschriftAngewandte Chemie / International Edition
Jahrgang56
DOIs
PublikationsstatusVeröffentlicht - 2017

Fingerprint

Xylose
Uridine Diphosphate
Isotopes
Enzymes
Sugars
Oxidation
NAD
Catalyst supports
Glucuronic Acid
Kinetics
Acids
Substrates
UDPglucuronate decarboxylase
UDP-apiose
3-hydroxybutanal

Fields of Expertise

  • Human- & Biotechnology

Dies zitieren

Isotope Probing of the UDP-Apiose/UDP-Xylose Synthase Reaction: Evidence of a Mechanism via a Coupled Oxidation and Aldol Cleavage. / Eixelsberger, Thomas; Horvat, Doroteja; Gutmann, Alexander; Weber, Hansjörg; Nidetzky, Bernd.

in: Angewandte Chemie / International Edition , Jahrgang 56, 2017, S. 2503 –2507.

Publikation: Beitrag in einer FachzeitschriftArtikelForschungBegutachtung

@article{e7c8dfc6cdf24707b86c65ef8ed437f1,
title = "Isotope Probing of the UDP-Apiose/UDP-Xylose Synthase Reaction: Evidence of a Mechanism via a Coupled Oxidation and Aldol Cleavage",
abstract = "The C-branched sugar d-apiose (Api) is essential for plant cell-wall development. An enzyme-catalyzed decarboxylation/pyranoside ring-contraction reaction leads from UDP-α-d-glucuronic acid (UDP-GlcA) to the Api precursor UDPa-d-apiose (UDP-Api). We examined the mechanism of UDPApi/UDP-α-d-xylose synthase (UAXS) with site-selectively 2H-labeled and deoxygenated substrates. The analogue UDP-2-deoxy-GlcA, which prevents C-2/C-3 aldol cleavage as the plausible initiating step of pyranoside-to-furanoside conversion, did not give the corresponding Api product. Kinetic isotope effects (KIEs) support an UAXS mechanism in which substrate oxidation by enzyme-NAD+ and retro-aldol sugar ring-opening occur coupled in a single rate-limiting step leading to decarboxylation. Rearrangement and ring-contracting aldol addition in an open-chain intermediate then give the UDP-Api aldehyde, which is intercepted via reduction by enzyme-NADH",
author = "Thomas Eixelsberger and Doroteja Horvat and Alexander Gutmann and Hansj{\"o}rg Weber and Bernd Nidetzky",
year = "2017",
doi = "10.1002/anie.201609288",
language = "English",
volume = "56",
pages = "2503 –2507",
journal = "Angewandte Chemie / International Edition",
issn = "1433-7851",
publisher = "Wiley-VCH",

}

TY - JOUR

T1 - Isotope Probing of the UDP-Apiose/UDP-Xylose Synthase Reaction: Evidence of a Mechanism via a Coupled Oxidation and Aldol Cleavage

AU - Eixelsberger, Thomas

AU - Horvat, Doroteja

AU - Gutmann, Alexander

AU - Weber, Hansjörg

AU - Nidetzky, Bernd

PY - 2017

Y1 - 2017

N2 - The C-branched sugar d-apiose (Api) is essential for plant cell-wall development. An enzyme-catalyzed decarboxylation/pyranoside ring-contraction reaction leads from UDP-α-d-glucuronic acid (UDP-GlcA) to the Api precursor UDPa-d-apiose (UDP-Api). We examined the mechanism of UDPApi/UDP-α-d-xylose synthase (UAXS) with site-selectively 2H-labeled and deoxygenated substrates. The analogue UDP-2-deoxy-GlcA, which prevents C-2/C-3 aldol cleavage as the plausible initiating step of pyranoside-to-furanoside conversion, did not give the corresponding Api product. Kinetic isotope effects (KIEs) support an UAXS mechanism in which substrate oxidation by enzyme-NAD+ and retro-aldol sugar ring-opening occur coupled in a single rate-limiting step leading to decarboxylation. Rearrangement and ring-contracting aldol addition in an open-chain intermediate then give the UDP-Api aldehyde, which is intercepted via reduction by enzyme-NADH

AB - The C-branched sugar d-apiose (Api) is essential for plant cell-wall development. An enzyme-catalyzed decarboxylation/pyranoside ring-contraction reaction leads from UDP-α-d-glucuronic acid (UDP-GlcA) to the Api precursor UDPa-d-apiose (UDP-Api). We examined the mechanism of UDPApi/UDP-α-d-xylose synthase (UAXS) with site-selectively 2H-labeled and deoxygenated substrates. The analogue UDP-2-deoxy-GlcA, which prevents C-2/C-3 aldol cleavage as the plausible initiating step of pyranoside-to-furanoside conversion, did not give the corresponding Api product. Kinetic isotope effects (KIEs) support an UAXS mechanism in which substrate oxidation by enzyme-NAD+ and retro-aldol sugar ring-opening occur coupled in a single rate-limiting step leading to decarboxylation. Rearrangement and ring-contracting aldol addition in an open-chain intermediate then give the UDP-Api aldehyde, which is intercepted via reduction by enzyme-NADH

U2 - 10.1002/anie.201609288

DO - 10.1002/anie.201609288

M3 - Article

VL - 56

SP - 2503

EP - 2507

JO - Angewandte Chemie / International Edition

JF - Angewandte Chemie / International Edition

SN - 1433-7851

ER -