Structural analysis of pituitary adenylate cyclase-activating polypeptides bound to phospholipid membranes by magic angle spinning solid-state NMR

Nobuyasu Komi, Kayo Okawa, Yukihiro Tateishi, Masahiro Shirakawa, Toshimichi Fujiwara, Hideo Akutsu
2007 Biochimica et Biophysica Acta - Biomembranes  
PACAP (pituitary adenylate cyclase-activating polypeptide) is a member of the VIP/secretin/glucagon family, which includes the ligands of class II G-protein coupled receptors. Since the recognition of PACAP by the receptor may involve the binding of PACAP to membranes, its membrane-bound structure should be important. We have carried out structural analysis of uniformly 13 C, 15 N labeled PACAP27 and its C-terminal truncated form PACAP(1-21)NH 2 (PACAP21) bound to membranes with high resolution
more » ... solid-state NMR. Phosphatidylcholine bilayers and phosphatidylcholine/phosphatidylglycerol bilayers were used for PACAP27 and PACAP21, respectively. Most backbone signals were assigned for PACAP27 and PACAP21. TALOS analysis revealed that both peptides take on extended conformations on the membranes. Dilution of PACAP21 did not change the conformation of the major part. Selective polarization transfer experiment confirmed that PACAP27 is interacting with the membranes. It was concluded that the interaction of PACAP with the membrane surface causes their extended conformation. PACAP27 is reported to take an α-helical conformation in dodecylphosphocholine micelles and membrane-binding peptides usually take similar conformations in micelles and in membranes. Therefore, the property of PACAP27 changing its conformation in response to its environment is unique. Its conformational flexibility may be associated with its wide variety of functions. The sequence of PACAP has been determined for several non-mammalian vertebrates and invertebrates, including chicken Galus domesticus [5], frog Rana ridibunda [6], salmon
doi:10.1016/j.bbamem.2007.10.015 pmid:17996724 fatcat:vbsbsjonijekdpu4itzbdo7xa4