Location of an alpha-helix in fragment 96-133 from bovine somatotropin by 1H NMR spectroscopy.
By use of two-dimensional NMR techniques most of the proton resonances (greater than 90%) are assigned for the tryptic digest fragment 96-133 of bovine somatotropin in 30% 2,2,2-trifluoroethanol-d3/70% H2O. Qualitative analysis of the nuclear Overhauser enhancement (NOE) data indicates that a region of alpha-helix spans residues 106-128, while the N- and C-terminal regions assume nonregular structures. Amide-exchange rates and comparison of two-dimensional NOE spectra indicate that the most stable piece of helix spans residues 120-125 and that this piece of helix is stable in water at 25 degrees C. Evidence is given to support the fact that intermolecular association of the helical segments stabilizes the helix.
Department of Molecular Biophysics and Biochemistry, School of Medicine, Yale University, New Haven, Connecticut 06510.
P R
PR
Gooley
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NE
MacKenzie
D000577:Amides / Q000378:metabolism; D000818:Animals; D002417:Cattle; D013006:Growth Hormone / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D010446:Peptide Fragments; D011487:Protein Conformation
D000577:Amides; D010446:Peptide Fragments; D013006:Growth Hormone