PMID: 10666574

Authors:

Tang L, Zhou YC, Lin ZJ

Title:

Structure of agkistrodotoxin in an orthorhombic crystal form with six molecules per asymmetric unit.

Journal:

Acta Crystallogr D Biol Crystallogr. 1999 Dec;55(Pt 12):1986-96.

Abstract:

The structure of agkistrodotoxin crystallized under basic conditions has been determined at 2.8 A resolution by the molecular-replacement technique and refined to a crystallographic R factor of 0.194 and a free R factor of 0.260 with good stereochemistry. The molecular packing in the crystal differs from other PLA(2)s. The six molecules in the asymmetric unit form three dimers linked by Ca(2+) ions in a near-perfect six-ligand octahedral coordinating system. Extensive intermolecular hydrophobic interactions occur at the interfacial recognition site of each neurotoxin molecule, which provides an insight into phospholipase A(2)-membrane interactions. This hydrophobic interaction-induced molecular association along the interfacial recognition site suggests a self-protection mechanism of agkistrodotoxin.