Download MendeleySolution structure of alpha-conotoxin PIA, a novel antagonist of alpha6 subunit containing nicotinic acetylcholine receptors
Chi, S.-W., Lee, S.-H., Kim, D.-H., Kim, J.-S., Olivera, B.M., McIntosh, J.M., Han, K.-H.(2005) Biochem Biophys Res Commun 338: 1990-1997
- PubMed: 16289101
- DOI: https://doi.org/10.1016/j.bbrc.2005.10.176
- Primary Citation of Related Structures:
1ZLC - PubMed Abstract:
alpha-Conotoxin PIA is a novel nicotinic acetylcholine receptor (nAChR) antagonist isolated from Conus purpurascens that targets nAChR subtypes containing alpha6 and alpha3 subunits. alpha-conotoxin PIA displays 75-fold higher affinity for rat alpha6/alpha3beta2beta3 nAChRs than for rat alpha3beta2 nAChRs. We have determined the three-dimensional structure of alpha-conotoxin PIA by nuclear magnetic resonance spectroscopy. The alpha-conotoxin PIA has an "omega-shaped" overall topology as other alpha4/7 subfamily conotoxins. Yet, unlike other neuronally targeted alpha4/7-conotoxins, its N-terminal tail Arg1-Asp2-Pro3 protrudes out of its main molecular body because Asp2-Pro3-Cys4-Cys5 forms a stable type I beta-turn. In addition, a kink introduced by Pro15 in the second loop of this toxin provides a distinct steric and electrostatic environment from those in alpha-conotoxins MII and GIC. By comparing the structure of alpha-conotoxin PIA with other functionally related alpha-conotoxins we suggest structural features in alpha-conotoxin PIA that may be associated with its unique receptor recognition profile.
Organizational Affiliation:
Protein Analysis and Design Laboratory, Division of Drug Discovery, Korea Research Institute of Bioscience and Biotechnology, Yusong P. O. Box 115, Daejon, Republic of Korea.
