Research Article
|
Combining crystallography and molecular dynamics: The case of Schistosoma
mansoni phospholipid
glutathione peroxidase
|
| Daniela Dimastrogiovanni 1, Massimiliano Anselmi 2, Adriana Erica Miele 1, Giovanna Boumis 1, Linn Petersson 1, Francesco Angelucci 1, Alfredo Di Nola 2, Maurizio Brunori 1, Andrea Bellelli 1 * |
1Dipartimento di Scienze Biochimiche A. Rossi Fanelli and
Istituto Pasteur, Fondazione Cenci Bolognetti,  Sapienza University
of Rome, Rome, Italy2Dipartimento di Chimica, Sapienza University
of Rome, Rome, Italy |
| email: Andrea Bellelli (andrea.bellelli@uniroma1.it) |
*Correspondence to Andrea Bellelli,
Dipartimento di Scienze Biochimiche, Sapienza University
of Rome, piazzale Aldo Moro 5, Rome 00185, Italy
Funded by:
Sapienza University
of Rome (Progetto Università 2006 e Ateneo Federato)
MIUR Italy (FIRB/Biologia
strutturale and FIRB/Proteomica); Grant Number: 2003-RBLA03B3KC_004,
2007-prot RBRN07BMCT
European Community - Research
Infrastructure Action (FP6 Structuring
the European Research Area Programme);
Grant Number: R II 3-CT-2004-506008
| KEYWORDS |
| atomic resolution crystal structure • ROS detoxification pathway • schistosomiasis • lipid GSH peroxidase • molecular dynamics simulations |
| ABSTRACT |
| Oxidative stress is a widespread challenge for living organisms, and especially so for parasitic ones, given the fact that their hosts can produce reactive oxygen species (ROS) as a mechanism of defense. Thus, long lived parasites, such as the flatworm Schistosomes, have evolved refined enzymatic systems capable of detoxifying ROS. Among these, glutathione peroxidases (Gpx) are a family of sulfur or selenium-dependent isozymes sharing the ability to reduce peroxides using the reducing equivalents provided by glutathione or possibly small proteins such as thioredoxin. As for other frontline antioxidant enzymatic systems, Gpxs are localized in the tegument of the Schistosomes, the outermost defense layer. In this article, we present the first crystal structure at 1.0 and 1.7 Å resolution of two recombinant SmGpxs, carrying the active site mutations Sec43Cys and Sec43Ser, respectively. The structures confirm that this enzyme belongs to the monomeric class 4 (phospholipid hydroperoxide) Gpx. In the case of the Sec to Cys mutant, the catalytic Cys residue is oxidized to sulfonic acid. By combining static crystallography with molecular dynamics simulations, we obtained insight into the substrate binding sites and the conformational changes relevant to catalysis, proposing a role for the unusual reactivity of the catalytic residue. Proteins 2009. © 2009 Wiley-Liss, Inc. |
Received: 9 February 2009; Revised: 4 June 2009; Accepted: 24 June 2009
| DIGITAL OBJECT IDENTIFIER (DOI) |