Crystal structure at 1.1 angstrom resolution of alpha-conotoxin PnIB: Comparison with alpha-conotoxins PnIA and GI

被引:77
作者
Hu, SH [1 ]
Gehrmann, J [1 ]
Alewood, PF [1 ]
Craik, DJ [1 ]
Martin, JL [1 ]
机构
[1] UNIV QUEENSLAND,CTR DRUG DESIGN & DEV,BRISBANE,QLD 4072,AUSTRALIA
关键词
D O I
10.1021/bi9713052
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
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 Angstrom and phased using the Shake-and-Bake direct methods program. PnIB crystals are orthorhombic and belong to the space group P2(1)2(1)2(1) with the following unit cell dimensions: a = 14.6 Angstrom, b = 26.1 Angstrom, and c = 29.2 Angstrom. 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.
引用
收藏
页码:11323 / 11330
页数:8
相关论文
共 43 条
[1]  
Blessing R. H., 1989, Journal of Applied Crystallography, V22, P396, DOI 10.1107/S0021889889001639
[2]  
Brunger A.T., 1992, X PLOR VERSION 3 1 M
[3]   FREE R-VALUE - A NOVEL STATISTICAL QUANTITY FOR ASSESSING THE ACCURACY OF CRYSTAL-STRUCTURES [J].
BRUNGER, AT .
NATURE, 1992, 355 (6359) :472-475
[4]   A new alpha-conotoxin which targets alpha 3 beta 2 nicotinic acetylcholine receptors [J].
Cartier, GE ;
Yoshikami, DJ ;
Gray, WR ;
Luo, SQ ;
Olivera, BM ;
McIntosh, JM .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (13) :7522-7528
[5]   Now we're cooking: New successes for shake-and-bake [J].
Ealick, SE .
STRUCTURE, 1997, 5 (04) :469-472
[6]   ACCURATE BOND AND ANGLE PARAMETERS FOR X-RAY PROTEIN-STRUCTURE REFINEMENT [J].
ENGH, RA ;
HUBER, R .
ACTA CRYSTALLOGRAPHICA SECTION A, 1991, 47 :392-400
[7]   NEW MOLLUSK-SPECIFIC ALPHA-CONOTOXINS BLOCK APLYSIA NEURONAL ACETYLCHOLINE-RECEPTORS [J].
FAINZILBER, M ;
HASSON, A ;
OREN, R ;
BURLINGAME, AL ;
GORDON, D ;
SPIRA, ME ;
ZLOTKIN, E .
BIOCHEMISTRY, 1994, 33 (32) :9523-9529
[8]   A NEW CONOTOXIN AFFECTING SODIUM CURRENT INACTIVATION INTERACTS WITH THE DELTA-CONOTOXIN RECEPTOR-SITE [J].
FAINZILBER, M ;
LODDER, JC ;
KITS, KS ;
KOFMAN, O ;
VINNITSKY, I ;
VANRIETSCHOTEN, J ;
ZLOTKIN, E ;
GORDON, D .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1995, 270 (03) :1123-1129
[9]   MERLOT, AN INTEGRATED PACKAGE OF COMPUTER-PROGRAMS FOR THE DETERMINATION OF CRYSTAL-STRUCTURES BY MOLECULAR REPLACEMENT [J].
FITZGERALD, PMD .
JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1988, 21 (03) :273-278
[10]   FUNCTIONAL ARCHITECTURE OF THE NICOTINIC ACETYLCHOLINE-RECEPTOR - FROM ELECTRIC ORGAN TO BRAIN [J].
GALZI, JL ;
REVAH, F ;
BESSIS, A ;
CHANGEUX, JP .
ANNUAL REVIEW OF PHARMACOLOGY AND TOXICOLOGY, 1991, 31 :37-72