The T-cell antigen receptor (TCR) is a cell surface protein complex that initiates immune responses upon interaction with antigens presented by the major histocompatibility complex. Molecular details of this transmembrane signaling process, in which the cytosolic signaling domain of the CD3-T cell receptor complex, TCR?, plays a central role, remain unknown. We characterize the association of TCR? with lipid membranes using SPR and neutron reflectometry. The binding of TCR? to membranes rich in anionic lipids has a dissociation constant, Kd ~ 10 �M. Minute amounts of phosphoinositides, PI(4,5,)P2, increase the affinity by more than 10-fold. NR shows the major portion of the peptide interfacially associated with the bilayer surface and a minor portion penetrating the bilayer deeply. This supports a model in which an a-helical containing ITAMs is aligned parallel to the membrane surface and another a-helical segment is inserted into the bilayer.

Association of the T-cell antigen receptor [zeta] subunit with the lipid membrane: Affinities and structure

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.