Sequence-specific H NMR assignments and secondary structure in the sea anemone polypeptide Stichodactyla helianthus neurotoxin I

Journal Article · Tue Feb 21 00:00:00 EST 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00430a060· OSTI ID:5648809

Fogh, R H; Mabbutt, B C; Kem, W R; Norton, R S ^[1]

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1. Univ. of New South Wales, Kensington (Australia)

Sequence-specific assignments are reported for the 500-MHz H nuclear magnetic resonance (NMR) spectrum of the 48-residue polypeptide neurotoxin I from the sea anemone Stichodactyla helianthus (Sh I). Spin systems were first identified by using two-dimensional relayed or multiple quantum filtered correlation spectroscopy, double quantum spectroscopy, and spin lock experiments. Specific resonance assignments were then obtained from nuclear Overhauser enhancement (NOE) connectivities between protons from residues adjacent in the amino acid sequence. Of a total of 265 potentially observable resonances, 248 (i.e., 94%) were assigned, arising from 39 completely and 9 partially assigned amino acid spin systems. The secondary structure of Sh I was defined on the basis of the pattern of sequential NOE connectivities. NOEs between protons on separate strands of the polypeptide backbone, and backbone amide exchange rates. Sh I contains a four-stranded antiparallel {beta}-sheet encompassing residues 1-5, 16-24, 30-33, and 40-46, with a {beta}-bulge at residues 17 and 18 and a reverse turn, probably a type II {beta}-turn, involving residues 27-30. No evidence of {alpha}-helical structure was found.

• OSTI ID: 5648809
• Journal Information: Biochemistry; (USA), Vol. 28:4; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
POLYPEPTIDES
MOLECULAR STRUCTURE
TOXINS
NUCLEAR MAGNETIC RESONANCE
CHEMICAL SHIFT
MOLLUSCS
OVERHAUSER EFFECT
PROTONS
ANIMALS
ANTIGENS
AQUATIC ORGANISMS
BARYONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
INVERTEBRATES
MAGNETIC RESONANCE
MATERIALS
NUCLEONS
ORGANIC COMPOUNDS
PEPTIDES
PROTEINS
RESONANCE
TOXIC MATERIALS
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