An NMR conformational analysis of a synthetic peptide Cn2(1–15)NH2–S–S–Acetyl–Cn2(52–66)NH2 from the New World Centruroides noxius 2 (Cn2) scorpion toxin: Comparison of the structure with those of the Centruroides scorpion toxins* *A preliminary account of this work was presented at the 39th Experimental NMR Conference, March 22–27, 1998, Asilomer, California, USA, Abstract 279, and the Canadian Federation of Biological Societies Annual Meeting, June 17–20, 1998, Edmonton, Alberta, Canada, Abstract 285.

Autor: Yamamoto, Hitoshi, Sejbal, Jan, York, Eunice, Stewart, John M., Possani, Lourival D., Kotovych, George
Zdroj: Biopolymers; 5 April 1999, Vol. 49 Issue: 4 p277-286, 10p
Abstrakt: The solution structure of a synthetic peptide, Cn2(1–15)NH2–S–S–acetyl–Cn2(52–66)NH2 from toxin 2 (Cn2) of the New World scorpion Centruroides noxius was determined using nmr and molecular dynamics calculations. The peptide has no significant secondary structure such as an α-helix or a β-sheet, yet it has a fixed conformation for the first chain. The backbone secondary structure involving residues 6–12 in this peptide shows an excellent overlap with the structures of natural neurotoxins from Centruroides sculpturatus Ewing. Residues 6– 9 form a distorted type I β-turn and residues 10–12 form a γ-turn. As residues 7–10 in the Centruroides toxins correspond to one of the regions of highest sequence variability, it may account for the species specificity and/or selectivity of toxic action. The conformation of this region evidently plays an important role in receptor recognition and in binding to the neutralizing monoclonal antibody BCF2 raised against the intact toxin. © 1999 John Wiley & Sons, Inc. Biopoly 49: 277–286, 1999
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