Protein–lipid interaction

4) How do peripheral membrane proteins which bind to the layer surface interact with lipids and influence their behavior?

A large research effort involves approaches to know whether proteins have binding sites which are specific for particular lipids and whether the protein–lipid complexes can be considered to be long-lived, on the order of the time required for the turnover a typical enzyme, that is 10−3 sec.

The overall view resulting from NMR experiments is 1) that the exchange rate between boundary and free lipids is rapid, (107 sec−1), 2) that the order parameters of the bound lipid are barely affected by being adjacent to proteins, 3) that the dynamics of the acyl chain reorientations are slowed only slightly in the frequency range of 109 sec−1, and 4) that the orientation and the dynamics of the polar headgroups are similarly unaffected in any substantial manner by being adjacent to transmembrane proteins.

[4] Solid-state NMR techniques have the potential to yield detailed information about the dynamics of individual amino acid residues within a membrane protein.

Misfolding processes, typically exposing hydrophobic regions of proteins, often are associated with binding to lipid membranes and subsequent aggregation, for example, during neurodegenerative disorders, neuronal stress and apoptosis.