Biomedical subjects

Ludovic Renault

Publications and source records attributed to Ludovic Renault.

5 recordsLinked to original sources

PubMed2006

Milestones in electron crystallography.

Electron crystallography determines the structure of membrane embedded proteins in the two-dimensionally crystallized state by cryo-transmission electron microscopy imaging and computer structure reconstruction. Milestones on the path to the structure are high-level expression, purification of functional protein, reconstitution into two-dimensional lipid membrane crystals, high-resolution imaging, and structure determination by computer image processing. Here we review the current state of these methods. We also created an Internet information exchange platform for electron crystallography, where guidelines for imaging and data processing method are maintained. The server (http://2dx.org) provides the electron crystallography community with a central information exchange platform, which is structured in blog and Wiki form, allowing visitors to add comments or discussions. It currently offers a detailed step-by-step introduction to image processing with the MRC software program. The server is also a repository for the 2dx software package, a user-friendly image processing system for 2D membrane protein crystals.

Cryoelectron Microscopy↗

PubMed2005

A. niger protein "EstA", perhaps a new electrotactin, defines a new class of fungal esterases within the alpha/beta hydrolase fold superfamily.

Protein EstA from Aspergillus niger was characterized through a multifaced approach involving molecular biology, bioinformatics, biophysical, biochemical and enzymatical analyses. EstA was identified as the lead member, within the superfamily of proteins with an alpha/beta-hydrolase fold, of a new class of fungal esterases that also contains predicted homologs from other fungus species of known broad host-range pathogenicity.

Aspergillus niger↗

PubMed2005

Structural insights into AChE inhibition by monoclonal antibodies.

The target sites of three inhibitory monoclonal antibodies, Elec403, 408 and 410, on eel AChE have been defined previously. Elec403 and 410 are directed toward distinct but overlapping epitopes at the enzyme peripheral site, while Elec408 binds to a distinct regulatory site on the enzyme surface, where the "back door" may be located. Elec410 also inhibits Bunganus fasciatus AChE. To investigate the molecular determinants for AChE inhibition by these antibodies, we have cloned and sequenced the IgGs, generated, purified, characterized the Fab molecules, and initiated crystallographic and theoretical modeling studies. Preliminary data are presented.

Acetylcholinesterase↗

PubMed2005

New friendly tools for users of ESTHER, the database of the alpha/beta-hydrolase fold superfamily of proteins.

The structural alpha/beta-hydrolase fold is characterized by a beta-sheet core of five to eight strands connected by alpha-helices to form a alpha/beta/alpha sandwich. The superfamily members, exemplified by the cholinesterases, diverged from a common ancestor into a number of hydrolytic enzymes displaying a wide range of substrate specificities, along with proteins with no recognized hydrolytic activity. In the enzymes, the catalytic triad residues are presented on loops of which one, the nucleophile elbow, is the most conserved feature of the fold. Of the other proteins, which all lack from one to all of the catalytic residues, some may simply be 'inactive' enzymes while others have been shown to be involved in heterologous surface recognition functions. The ESTHER (for esterases, alpha/beta-hydrolase enzymes and relatives) database (http://bioweb.ensam.inra.fr.esther) gathers and annotates all the published pieces of information (gene and protein sequences; biochemical, pharmacological, and structural data) related to the superfamily, and connects them together to provide the bases for studying structure-function relationships within the superfamily. The most recent developments of the database are presented.

Cholinesterases↗

PubMed2004

ESTHER, the database of the alpha/beta-hydrolase fold superfamily of proteins.

The alpha/beta-hydrolase fold is characterized by a beta-sheet core of five to eight strands connected by alpha-helices to form a alpha/beta/alpha sandwich. In most of the family members the beta-strands are parallels, but some show an inversion in the order of the first strands, resulting in antiparallel orientation. The members of the superfamily diverged from a common ancestor into a number of hydrolytic enzymes with a wide range of substrate specificities, together with other proteins with no recognized catalytic activity. In the enzymes the catalytic triad residues are presented on loops, of which one, the nucleophile elbow, is the most conserved feature of the fold. Of the other proteins, which all lack from one to all of the catalytic residues, some may simply be 'inactive' enzymes while others are known to be involved in surface recognition functions. The ESTHER database (http://bioweb.ensam.inra.fr/esther) gathers and annotates all the published information related to gene and protein sequences of this superfamily, as well as biochemical, pharmacological and structural data, and connects them so as to provide the bases for studying structure-function relationships within the family. The most recent developments of the database, which include a section on human diseases related to members of the family, are described.

Animals↗