Kweon, J Lee, HJ Kim, YM Choi, YS Lee, KB 2024-01-21T15:09:04Z 2024-01-21T15:09:04Z 2022-01-11 1999-08-06 0014-5793 https://pubs.kist.re.kr/handle/201004/141994 The structure of bovine growth hormone releasing factor (bGHRF) consisting of 44 amino acids has been studied in CD and H-1 nuclear magnetic resonance (NMR) spectroscopy in conjunction with molecular modeling. Since bGHRF does not have an ordered structure in water alone, a 30% 2,2,2trifluoroethanol (TFE) aqueous solvent was used to induce considerable alpha-helical structures, which corresponds to a helical content of similar to 62% as determined by circular dichroism (CD), The secondary structure was obtained from nuclear Overhauser enhancement and (3)J(HN alpha) coupling constant in 30% TFE solution. Three-dimensional structures consistent with NMR data were generated by using distance geometry calculation. A set of 267 interproton distances derived from nuclear Overhauser effect correlation spectroscopy (NOESY) experiments and coupling constants were used. From the initial random conformations, 50 distance geometry structures with minimal violations were selected for further refinement, The 14 best structures were obtained after simulated annealing calculation with energy minimization, The structure of bGHRF in 30% TFE solution was characterized by one alpha-helix (residues 8-19), two poorly constrained helices (residues 23-27 and residues 31-34) and a beta I(III)-turn fragment (residues 20-23; phi(i+1) = -53.1 degrees, Psi(i+1) = -19.6 degrees, phi(i+2) = -59.9 degrees, Psi(i+2) = -20.6 degrees) connected by the segments of less defined structures in N-terminal and Omega-shaped flexible C-terminal determined from NOESY cross peaks between helical segment (residues 14-18) and tail fragment (residues 42-44), The obtained structure will play an important role toward the understanding of the structural and functional role of the GHRF. (C) 1999 Federation of European Biochemical Societies. English ELSEVIER SCIENCE BV NUCLEAR-MAGNETIC-RESONANCE CIRCULAR-DICHROISM CHEMICAL-SHIFT ANALOGS SPECTROSCOPY DYNAMICS PROTEINS BINDING PROGRAM HELIX Solution conformation on bovine growth hormone releasing factor by H-1 NMR and molecular modeling Article 10.1016/S0014-5793(99)00976-X 1 FEBS LETTERS, v.456, no.2, pp.343 - 348 FEBS LETTERS 456 2 343 348 scie scopus 000081971600024 2-s2.0-0032782910 Biochemistry & Molecular Biology Biophysics Cell Biology Biochemistry & Molecular Biology Biophysics Cell Biology Article NUCLEAR-MAGNETIC-RESONANCE CIRCULAR-DICHROISM CHEMICAL-SHIFT ANALOGS SPECTROSCOPY DYNAMICS PROTEINS BINDING PROGRAM HELIX growth hormone releasing factor CD NMR three-dimensional structure distance geometry restrained molecular dynamics