Analytical Sciences

Evaluation of the Membrane-binding Properties of the Proximal Region of the Angiotensin II Receptor (AT_1A) Carboxyl Terminus by Surface Plasmon Resonance

Hiroshi KAMIMORI,*^,** Sharon UNABIA,* Walter G. THOMAS,*** and Marie-Isabel AGUILAR*

*Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
**Shionogi Research Laboratories, Shionogi & Co. Ltd., Fukushima-ku, Osaka 553-0002, Japan
***The Baker Medical Research Institute, St Kilda Road Central, Melbourne 8008, Australia

The proximal region of the angiotensin II receptor (AT_1A) carboxyl-terminus (known as helix VIII) is important for receptor function. In this study, we used surface plasmon resonance (SPR) to examine the interaction of helix VIII-derived peptides with three model lipid membranes. The membrane-binding properties of these synthetic peptides, as well as a series of peptide analogues with modified amino acid sequences, could be explained by both amino acid sequence and kinetic binding data by SPR. The helix VIII peptides showed a higher affinity for lipid membranes that contained negatively charged phospholipid, rather than zwitterionic phospholipid. The findings of an SPR study may be useful for estimating the cooperative binding of intracellular receptor domains with G proteins and the components of the lipid bilayer.

J-STAGE: View this article in J-STAGE