Isolation, purification, crystallization and preliminary X-ray analysis of β₁-bungarotoxin from Bungarus caeruleus (Indian common krait)

β-Bungarotoxin is a heterodimeric neurotoxin consisting of a phospholipase A₂ subunit linked by a disulfide bond to a K⁺ channel binding subunit, which is a member of of the Kunitz protease-inhibitor subfamily. Purified β₁-bungarotoxin was crystallized using microdialysis techniques. The rectangular-shaped crystals are ortho­rhombic, space group C222₁, with unit-cell dimensions a = 80.7, b = 82.5, c = 56.9 Å. The crystals have a calculated V_m of 2.35 ų Da⁻¹ for one molecule in the asymmetric unit. This corresponds to a solvent content of 48%. X-ray intensity data were collected to 2.6 Å resolution. The data set is 97.4% complete.