2I28

Solution Structure of alpha-Conotoxin BuIA

Summary for 2I28

• Entry DOI: 10.2210/pdb2i28/pdb
• Descriptor: Alpha-conotoxin BuIA (1 entity in total)
• Functional Keywords: alpha-helix, beta-turn, two disulfide bonds, c-terminal amidation, toxin
• Cellular location: Secreted: P69657
• Total number of polymer chains: 1
• Total formula weight: 1314.60

Authors

Chi, S.-W.,Kim, D.-H.,Olivera, B.M.,McIntosh, J.M.,Han, K.-H. (deposition date: 2006-08-16, release date: 2006-10-31, Last modification date: 2024-10-16)

Primary citation

Chi, S.-W.,Kim, D.-H.,Olivera, B.M.,McIntosh, J.M.,Han, K.-H.
NMR structure determination of alpha-conotoxin BuIA, a novel neuronal nicotinic acetylcholine receptor antagonist with an unusual 4/4 disulfide scaffold
Biochem.Biophys.Res.Commun., 349:1228-1234, 2006

PubMed Abstract: We have determined a high-resolution three-dimensional structure of alpha-conotoxin BuIA, a 13-residue peptide toxin isolated from Conus bullatus. Despite its unusual 4/4 disulfide bond layout alpha-conotoxin BuIA exhibits strong antagonistic activity at alpha6/alpha3beta2beta3, alpha3beta2, and alpha3beta4 nAChR subtypes like some alpha4/7 conotoxins. alpha-Conotoxin BuIA lacks the C-terminal beta-turn present within the second disulfide loop of alpha4/7 conotoxins, having only a "pseudo omega-shaped" molecular topology. Nevertheless, it contains a functionally critical two-turn helix motif, a feature ubiquitously found in alpha4/7 conotoxins. Such an aspect seems mainly responsible for similarities in the receptor recognition profile of alpha-conotoxin BuIA to alpha4/7 conotoxins. Structural comparison of alpha-conotoxin BuIA with alpha4/7 conotoxins and alpha4/3 conotoxin ImI suggests that presence of the second helical turn portion of the two-turn helix motif in alpha4/7 and alpha4/4 conotoxins may be important for binding to the alpha3 and/or alpha6 subunit of nAChR.

PubMed: 16979596
DOI: 10.1016/j.bbrc.2006.08.164

Experimental method

SOLUTION NMR