Biophysics of Macromolecules and their Interactions - CNRS URA 2185

2011-Annual Report

Molecular-scale biophysical approaches are a privileged link between the atomic-level structural descriptions and the spatiotemporal in situ studies, providing invaluable information about the energetics and dynamics of biological macromolecules and assemblies in a relatively short time-scale and in close-to-physiological conditions.

The Centre of Biophysics of Macromolecules and their Interactions (french acronym: PFBMI) federates a wide set of state-of-the-art equipment, adapted in priority to the needs of the research teams of the Pasteur Institute and its International Network, together with the well-established technical and methodological expertise. This core facility, which is unique in France, provides a scientific environment conducive to world- class research in the field of macromolecular science.

The following technologies are presently available (december 2011):
1) Analytical ultracentrifugation: ProteomeLab XL I & Optima XL-A ultracentrifuges (Beckman-Coulter). 2) Circular dichroism: Aviv 215 spectropolarimeter (Aviv Biomedical).
3) Dual polarisation interferometry: Analight 4D interferometer (Farfield-Biolin).

4) Fluorescence spectroscopy: Quantamaster QM4CW fluorimeter (Photon Technology International), with polarisation and time-resolved fluorescence modules ; KinetAsyst SF61-DX2 “stopped flow” instrument (TgK Scientific), with a polarisation module.

5) Infrared spectroscopy: FTIR 6100 spectrometer (Jasco), with an attenuated total reflectance accessory.

6) Light scattering: DynaPro MS800 and DynaPro PlateReader dynamic light scattering instruments (Wyatt) ; TDAmax light scattering-intrinsic viscosity-refractive index triple detector array (Malvern), coupled to a size exclusion chromatography system.

7) Microcalorimetry: ITC200 and VP-ITC isothermal titration calorimeters ; VP-DSC differential scanning calorimeter, with a Pressure Perturbation Calorimetry accessory (PPC) (MicroCal-GE Healthcare).

8) Surface plasmon resonance: Biacore 2000 and Biacore X100 biosensors (GE Healthcare), and ProteOn XPR36 protein interaction array system (Bio-Rad)

People wishing to use the instruments of the PFBMI, or seeking expert advice related to these technologies, should send an e-mail to the following address: biophysique@pasteur.fr . Applications can be made at any time, with the support of instructions and down-loadable forms available from our Web site.

Experiments can be carried out according to 3 different schemes: 1) instrument allocation after user training; 2) service provision; 3) scientific collaboration.

Activity Report 2011 - Institut Pasteur

The 16 instruments and the know-how of the PFBMI have attracted more than 120 projects in the past 5 years, in association with 33 Research Units of the Institut Pasteur (from all 10 Scientific Departments) and 22 laboratories from other institutions (french or foreign), leading to 45 peer-reviewed publications.

Below are listed the topics of some of the scientific collaborations in which the PFBMI has been involved since 2007, and the references of the resulting publications:

1) Characterization of the role of coupling between binding and folding in the recognition between the secretin of Klebsiella oxytoca and its dedicated chaperone (Mol. Microbiol. (2011) 82, 1422-1432; J. Biol. Chem. (2011) 286, 38833-38843).

2) Structural and dynamic characterization of the mechanism of activation of the human prolactin receptor and of the properties of hormone-based antagonists (J. Mol. Biol. (2010) 404, 112-126; J. Biol. Chem (2010) 285, 8422-8433; J. Biol. Chem (2007) 282, 33118-33131)

3) Biophysical characterization of the translocation process of the Bordetella pertussis adenylate cyclase toxin (Biophys. J. (2010) 99, 3744-3753; Biochemistry (2010) 49, 318-328; J. Biol. Chem (2009) 284, 1781-1789)

4) Elucidation of the structural basis of the biological properties of the multimodular erythrocyte membrane protein 1 of Plasmodium falciparum (PfEMP1) (PNAS (2011) 108, 5243-5248; PNAS (2010) 107, 4884-4889; Mol. Biochem. Parasitol. (2010) 170, 84-92 and 173, 115-122)

5) Role of the unorthodox activator Crl in the regulation of the σS factor activity and of the transcription machinery of Escherichia coli (J. Bacteriol. (2010) 192, 6401-6410; J. Biol. Chem. (2008) 283, 33455-33464)

6) Characterization of the mechanism of action of CymR, central regulator of the cysteine metabolism in Bacillus subtilis (FEBS J. (2011) 278, 2689-2701; J. Biol. Chem (2008) 283, 33561-33560)

7) Physico-chemical characterization of the phosphorylation-dependent molecular switch of GarA, an FHA- domain containing protein of Mycobacterium tuberculosis (FEBS Lett. (2009) 583, 301-307)

8) Structure-function study of the recognition between small G proteins of the Arf family and thir JIP effectors (EMBO Journal (2009) 28, 2835-2845)

9) Development of tandem proteins allowing to trap efficiently polyubiquitylated proteins (EMBO Rep (2009) 10, 1250-1258)

Activity Report 2011 - Institut Pasteur