Exploring the gas access routes in a [NiFeSe] hydrogenase using crystals pressurized with krypton and oxygen
- PDF / 1,732,905 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 94 Downloads / 144 Views
ORIGINAL PAPER
Exploring the gas access routes in a [NiFeSe] hydrogenase using crystals pressurized with krypton and oxygen Sónia Zacarias1 · Adriana Temporão1 · Philippe Carpentier2,3 · Peter van der Linden4 · Inês A. C. Pereira1 · Pedro M. Matias1,5 Received: 4 June 2020 / Accepted: 20 August 2020 © Society for Biological Inorganic Chemistry (SBIC) 2020
Abstract Hydrogenases are metalloenzymes that catalyse both H2 evolution and uptake. They are gas-processing enzymes with deeply buried active sites, so the gases diffuse through channels that connect the active site to the protein surface. The [NiFeSe] hydrogenases are a special class of hydrogenases containing a selenocysteine as a nickel ligand; they are more catalytically active and less O 2-sensitive than standard [NiFe] hydrogenases. Characterisation of the channel system of hydrogenases is important to understand how the inhibitor oxygen reaches the active site to cause oxidative damage. To this end, crystals of Desulfovibrio vulgaris Hildenborough [NiFeSe] hydrogenase were pressurized with krypton and oxygen, and a method for tracking labile O 2 molecules was developed, for mapping a hydrophobic channel system similar to that of the [NiFe] enzymes as the major route for gas diffusion. Keywords Hydrogenase · Selenium · Gas channels · High-pressure derivatization
Introduction Hydrogenases are gas-processing enzymes with deeply buried active sites; as a consequence, gases such as H 2 (substrate and product) and inhibitors (O2 and CO) have to diffuse several nanometers into the protein interior to reach the active site. The question that emerged when the first hydrogenase Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00775-020-01814-y) contains supplementary material, which is available to authorized users. * Pedro M. Matias [email protected] 1
Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780‑157 Oeiras, Portugal
2
European Synchrotron Radiation Facility, Grenoble, France
3
Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Laboratoire Chimie et Biologie des Métaux (LCBM), Université Grenoble Alpes, CNRS, CEA, Grenoble, France
4
Partnership for Soft Condensed Matter, European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS 40220, 38043 Grenoble, France
5
iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780‑901 Oeiras, Portugal
structure appeared [1] was whether the diffusion of gases inside the protein occurs is a free random process, or instead organized through specific channels. Montet and co-workers [2] were pioneers in investigating hydrogenase gas accessibility, using Xenon-derivatized crystals of D. gigas [NiFe] hydrogenase, which lead to the identification of hydrophobic channels through which gases can diffuse from the surface of the molecule to reach the active site. X-ray crystallography has been used to study the interaction between biomolecules and gases,
Data Loading...
