Presentation CD

Presentation

Studying macromolecules (and in particular proteins) by circular dichroism allows to obtain information about their folding. Circular dichroism (CD) spectroscopy measures differences in the absorption of left-handed polarized light versus right-handed polarized light which arise due to structural asymmetry. For proteins, far UV (180-260 nm) and near UV (250-330 nm) circular dichroism measurements give insight respectively into their secondary structure content and their tertiary organization.

Typical far UV spectra signature for α-helices, β-sheet and random coil

CD is particularly useful for monitoring changes in structure upon ligand binding or changes to the protein’s environment.

Thermal stability of folded molecules can be determined by performing temperature gradient to the sample. Similarly, conformational stability of a molecule and structural changes induced by complex formation can be checked at constant temperature by adding step by step chemical denaturation agents.

Application

• Estimation of protein and nucleic acid conformation (secondary and tertiary structure)
• Determination of conformational changes (due to the interactions of asymmetric molecules) : Protein-protein interactions - Protein-DNA interactions - Protein-Ligand interactions - DNA-Ligand interactions
• Determination of the thermodynamics of folding and unfolding of proteins and nucleic acids (thermal or chemical denaturation)
• Kinetics of folding and unfolding of macromolecules

Key words

Secondary structure, tertiary organization, Interactions, Kinetics of folding and unfolding

Staff

Manager: Caroline Mas
Office: CIBB room 017
Platform: CIBB room 001

Specific Equipment

MOS500 from Biologic

Access mode

Users must read the conditions of use of the instruments as well as of the management of the services provided:

Instrument allocation after user training:

• No theoretical training is provided for CD instrument
• Training on the instrument is provided the day of your first experiment by the instrument manager.
• After demonstrating his autonomy, the user will be able to use the instrument in complete independence

• Contact the platform manage to arrange a meeting if necessary

Cost

Academics: Participation to the maintenance fees
Industrials: Please contact us for cost information

Location

The Biophysical platform is located in the Carl-Ivar Brändén Building, ground floor, room 001 (Shared Building C).

How to make a request

To make a booking request, fill this request form here

CD Booking

Samples

Only non-pathogenic biological samples are accepted. Decree of the July 18, 1994 establishing the list of biological pathogens, amended by Decrees of April 17, 1997 and June 30, 1998 (Decrees in French). The list of biological pathogens is available on the website of the IPBS.

• Typical Sample :
  • Purity of protein : <90%)
  • Concentration : 2 to 20µM
  • Volume : 10 to 1000µl (Best 300µl)
  • Recommended Buffer : NaP 20mM and Naf 150mM
  • Decrease the salf (Cl) concentration to increase the sensitivity.

Acknowledgements in publications:

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The user agrees to promote the obtained results by mentioning the platform in the acknowledgements in case of publication or scientific communication and to communicate the reference of the article to the responsible for the platform.

Acknowledgements in publications:

Please find below the sentence that has to be written in all publications based on our UAR platforms:
"This work used the platforms of the Grenoble Instruct-ERIC center (ISBG ; UAR 3518 CNRS-CEA-UGA-EMBL) within the Grenoble Partnership for Structural Biology (PSB), supported by FRISBI (ANR-10-INBS-0005-02) and GRAL, financed within the University Grenoble Alpes graduate school (Ecoles Universitaires de Recherche) CBH-EUR-GS (ANR-17-EURE-0003). We thank Caroline Mas for assistance and/or access to the biophysics platform."