Mechanical matching between ligand and receptor

ANA PEÑAHERRERA

Londres

Conferencia; Single-Molecule Microscopy and Spectroscopy: Faraday Discussion; 2015

Royal Society of Chemistry

Interactions between ligands and receptors and subsequent ?locking? must involve someresistance to unbinding, manifesting itself as an interaction force. At body temperature,spontaneous unbinding will occur, however, external forces are required to acceleratethis process. Bearing in mind the potential forces that the receptor?ligand complex islikely to be subjected to in a biological environment, it might be hypothesised that thereis some mechanical matching between the receptor and ligand. To test this hypothesis,various receptor and ligand pairs were unfolded in their entirety in order to determinetheir total unfolding force. In this way, the total force to unfold the protein could bedetermined, allowing a comparison between ligand and receptor pairs. The interest ofthis work is to examine the interaction between five proteins and a mica surface by AFMwithout any modification to preserve the natural elastic properties of the proteinmolecules during the force measurements. The results showed a mechanical matchingbetween GP120 (ligand) and CD4 (receptor) when analysing the total force required tounfold the same number of domains or events shown by the force distance curves ofthese proteins.