title: Sequential 1H-NMR assignments and secondary structure of the sea anemone polypeptide anthopleurin-A.
abstract: The sequence-specific assignment of resonances in the 500-MHz 1H-NMR spectrum of a cardioactive sea anemone polypeptide, anthopleurin-A, is described. The assignment procedure involved analysis of two-dimensional phase-sensitive multiple-quantum-filtered, double-quantum, homonuclear Hartmann-Hahn and nuclear Overhauser effect spectra. Using sequential information, specific assignments have been made for resonances arising from all 49 amino acid residues. Resonances arising from a number of residues in a minor conformer present in solution are also assigned. These results greatly extend previous resonance assignments made from spectra acquired at 300 MHz [Gooley, P. R. and Norton, R. S. (1985) Eur. J. Biochem. 153, 529-539] and provide the basis for a more accurate definition of the conformation of anthopleurin-A in aqueous solution. The secondary structure includes a four-stranded antiparallel beta-sheet encompassing residues 2-4, 21-23, 34-36 and 45-49, and possibly a beta-bulge located at Ser-19 and Gly-20. A type II beta-turn is formed by residues 30-33. These structural elements also occur within other related sea anemone polypeptides, but the conformation of the small loop region containing Pro-41 appears to be unique to anthopleurin-A.
authors.affiliation: School of Biochemistry, University of New South Wales, Kensington, Australia.
authors.forename: B C
authors.initials: BC
authors.lastname: Mabbutt
authors.forename: R S
authors.initials: RS
authors.lastname: Norton
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D003063:Cnidaria / Q000378:metabolism*; D006860:Hydrogen Bonding; D036341:Intercellular Signaling Peptides and Proteins; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000302:isolation & purification*; D011487:Protein Conformation; D012615:Sea Anemones / Q000378:metabolism*; D012996:Solutions
chemical_list: D000596:Amino Acids; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D012996:Solutions; C012746:anthopleurin-A