The type 1 angiotensin (AT1) receptor belongs to G protein coupled receptors (GPCR) superfamily. Conformational studies of GPCR peptide fragments require the use of systems that mimic the receptor environment. The current study aims to investigate the interaction of the peptide fragment Ac-YRWPFGNYLCONH2 (fEC1), corresponding to amino acid residues 92 -100 of the first extracellular loop of the human AT1 receptor, with model membranes –micelles and large unilamellar vesicles (LUV). The micelles were prepared from lysophospholipids: 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine (LPC) and 1-palmitoyl-2-hydroxysn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (LPG) and, LUVs were prepared from 1-palmitoyl-2oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (POPG). The peptide fEC1 was synthesized by solid-phase sy...

The type 1 angiotensin (AT1) receptor belongs to G protein coupled receptors (GPCR) superfamily. Conformational studies of GPCR peptide fragments require the use of systems that mimic the receptor environment. The current study aims to investigate the interaction of the peptide fragment Ac-YRWPFGNYL-CONH2 (fEC1), corresponding to amino acid residues 92 -100 of the first extracellular loop of the human AT1 receptor, with model membranes –micelles and large unilamellar vesicles (LUV). The micelles were prepared from lysophospholipids: 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine (LPC) and 1-palmitoyl-2-hydroxy-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (LPG) and, LUVs were prepared from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (POPG). The peptide fEC1 was synthesized by solid-phase...

The type 1 receptor for angiotensin (AT1) is an important mediator of the vasoconstrictor functions of angiotensin II. During the activation process of the receiver, it undergoes structural alteration that leads to the process of signal transduction. In the present study, the conformational properties of the peptide fragment Ac-YRWPFGNYL-CONH2 (fEC1) corresponding to the first extracellular loop of the human AT1 receptor both in aqueous medium and in the presence of systems that mimics the biological membrane were investigated. In this way, micelles and large unilamellar vesicles (LUV) -both anionic and zwitterionic in nature- were used as biomimetic systems. The micelles were prepared from the lysophospholipids: 1-palmitoyl-2-hydroxy-phosphatidylcholine (LPC) and 1-palmitoyl-2-hydroxy-phosphatidylglycerol (LPG), whereas, the LUV were prepared from 1-palmitoyl- 1-oleoyl-phosphatidylcholi...