TY - JOUR
T1 - Unique helical conformation of the fourth cytoplasmic loop of the CB1 cannabinoid receptor in a negatively charged environment
AU - Grace, Christy R.R.
AU - Cowsik, Sudha M.
AU - Shim, Joong Youn
AU - Welsh, William J.
AU - Howlett, Allyn C.
N1 - Funding Information:
Supported by NIDA Grants R01-DA03690, R01-DA06312, K05-DA00182, and U24-DA12385. The staff members of the National 500 MHz facility at the Sophisticated Instruments Facility, Indian Institute of Science, Bangalore, India, are gratefully acknowledged. Special help from Ms. Anjali Dike is greatly appreciated.
PY - 2007/9
Y1 - 2007/9
N2 - The proximal portion of the C-terminus of the CB1 cannabinoid receptor is a primary determinant for G-protein activation. A 17 residue proximal C-terminal peptide (rodent CB1 401-417), the intracellular loop 4 (IL4) peptide, mimicked the receptor's G-protein activation domain. Because of the importance of the cationic amino acids to G-protein activation, the three-dimensional structure of the IL4 peptide in a negatively charged sodium dodecyl sulfate (SDS) micellar environment has been studied by two-dimensional proton nuclear magnetic resonance (2D 1H NMR) spectroscopy and distance geometry calculations. Unambiguous proton NMR assignments were carried out with the aid of correlation spectroscopy (DQF-COSY and TOCSY) and nuclear Overhauser effect spectroscopy (NOESY and ROESY) experiments. The distance constraints were used in torsion angle dynamics algorithm for NMR applications (DYANA) to generate a family of structures which were refined using restrained energy minimization and dynamics. In water, the IL4 peptide prefers an extended conformation, whereas in SDS micelles, 310-helical conformation is induced. The predominance of 310-helical domain structure in SDS represents a unique difference compared with structure in alternative environments, which can significantly impact global electrostatic surface potential on the cytoplasmic surface of the CB1 receptor and might influence the signal to the G-proteins.
AB - The proximal portion of the C-terminus of the CB1 cannabinoid receptor is a primary determinant for G-protein activation. A 17 residue proximal C-terminal peptide (rodent CB1 401-417), the intracellular loop 4 (IL4) peptide, mimicked the receptor's G-protein activation domain. Because of the importance of the cationic amino acids to G-protein activation, the three-dimensional structure of the IL4 peptide in a negatively charged sodium dodecyl sulfate (SDS) micellar environment has been studied by two-dimensional proton nuclear magnetic resonance (2D 1H NMR) spectroscopy and distance geometry calculations. Unambiguous proton NMR assignments were carried out with the aid of correlation spectroscopy (DQF-COSY and TOCSY) and nuclear Overhauser effect spectroscopy (NOESY and ROESY) experiments. The distance constraints were used in torsion angle dynamics algorithm for NMR applications (DYANA) to generate a family of structures which were refined using restrained energy minimization and dynamics. In water, the IL4 peptide prefers an extended conformation, whereas in SDS micelles, 310-helical conformation is induced. The predominance of 310-helical domain structure in SDS represents a unique difference compared with structure in alternative environments, which can significantly impact global electrostatic surface potential on the cytoplasmic surface of the CB1 receptor and might influence the signal to the G-proteins.
KW - Cell surface 7-transmembrane receptors
KW - G-protein coupled receptors
KW - Signal transduction mechanisms
KW - Sodium dodecyl sulfate (SDS) micelles
KW - Two-dimensional proton nuclear magnetic resonance (2D H NMR) spectroscopy
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U2 - 10.1016/j.jsb.2007.04.004
DO - 10.1016/j.jsb.2007.04.004
M3 - Article
C2 - 17524664
AN - SCOPUS:34548386281
VL - 159
SP - 359
EP - 368
JO - Journal of Structural Biology
JF - Journal of Structural Biology
SN - 1047-8477
IS - 3
ER -