1feo
From Proteopedia
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Solution structure of omega-conotoxin MVIIA with C-terminal Gly
Overview
Nuclear magnetic resonance spectroscopy was used to characterize the, solution structure and backbone dynamics of a putative precursor form of, omega-conotoxin MVIIA, a 25-amino-acid residue peptide antagonist of, voltage-gated Ca(2+) channels. The mature peptide is found in the venom of, a fish-hunting marine snail Conus magus and contains an amidated carboxyl, terminus that is generated by oxidative cleavage of a Gly residue. The, form examined in this study is identical to the mature peptide except for, the presence of the unmodified carboxy-terminal Gly. This form, referred, to as omega-MVIIA-Gly, has previously been shown to refold and form its, disulfides more efficiently than the mature form, suggesting that the, presence of the terminal Gly may favor folding in vivo. The nuclear, magnetic resonance (NMR) structure determination indicated that the fold, of omega-MVIIA-Gly is very similar to that previously determined for the, mature form, but revealed that the terminal Gly residue participates in a, network of hydrogen bonds involving both backbone and side chain atoms, very likely accounting for the enhanced stability and folding efficiency., (15)N relaxation experiments indicated that the backbone is well ordered, on the nanosecond time scale but that residues 9-15 undergo a, conformational exchange processes with a time constant of approximately 35, microseconds. Other studies have implicated this segment in the binding of, the peptide to its physiological target, and the observed motions may play, a role in allowing the peptide to enter the binding site
About this Structure
1FEO is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Solution structure and backbone dynamics of an omega-conotoxin precursor., Goldenberg DP, Koehn RE, Gilbert DE, Wagner G, Protein Sci. 2001 Mar;10(3):538-50. PMID:11344322
Page seeded by OCA on Tue Nov 20 14:51:30 2007
