1AKG

ALPHA-CONOTOXIN PNIB FROM CONUS PENNACEUS

1AKG の概要

• エントリーDOI: 10.2210/pdb1akg/pdb
• 分子名称: ALPHA-CONOTOXIN PNIB (2 entities in total)
• 機能のキーワード: acetylcholine receptor antagonist, alpha-conotoxin
• 由来する生物種: Conus pennaceus
• 細胞内の位置: Secreted: P50985
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 1640.90

構造登録者

Hu, S.-H.,Martin, J.L. (登録日: 1997-05-18, 公開日: 1998-05-20, 最終更新日: 2024-10-23)

主引用文献

Hu, S.H.,Gehrmann, J.,Alewood, P.F.,Craik, D.J.,Martin, J.L.
Crystal structure at 1.1 A resolution of alpha-conotoxin PnIB: comparison with alpha-conotoxins PnIA and GI.
Biochemistry, 36:11323-11330, 1997

PubMed Abstract: Conotoxins are small, cysteine-rich peptides isolated from the venom of Conus spp. of predatory marine snails, which selectively target specific receptors and ion channels critical to the functioning of the neuromuscular system. alpha-Conotoxins PnIA and PnIB are both 16-residue peptides (differing in sequence at only two positions) isolated from the molluscivorous snail Conus pennaceus. In contrast to the muscle-selective alpha-conotoxin GI from Conus geographus, PnIA and PnIB block the neuronal nicotinic acetylcholine receptor (nAChR). Here, we describe the crystal structure of PnIB, solved at a resolution of 1.1 A and phased using the Shake-and-Bake direct methods program. PnIB crystals are orthorhombic and belong to the space group P212121 with the following unit cell dimensions: a = 14.6 A, b = 26.1 A, and c = 29.2 A. The final refined structure of alpha-conotoxin PnIB includes all 16 residues plus 23 solvent molecules and has an overall R-factor of 14.7% (R-free of 15.9%). The crystal structures of the alpha-conotoxins PnIB and PnIA are solved from different crystal forms, with different solvent contents. Comparison of the structures reveals them to be very similar, showing that the unique backbone and disulfide architecture is not strongly influenced by crystal lattice constraints or solvent interactions. This finding supports the notion that this structural scaffold is a rigid support for the presentation of important functional groups. The structures of PnIB and PnIA differ in their shape and surface charge distribution from that of GI.

PubMed: 9298951
DOI: 10.1021/bi9713052

実験手法

X-RAY DIFFRACTION (1.1 Å)