1IJC

Solution Structure of Bucandin, a Neurotoxin from the Venom of the Malayan Krait

1IJC の概要

• エントリーDOI: 10.2210/pdb1ijc/pdb
• 関連するPDBエントリー: 1f94
• NMR情報: BMRB: 5097
• 分子名称: bucandin (1 entity in total)
• 機能のキーワード: three-finger motif, two antiparallel beta-sheets, two and four stranded beta-sheets, toxin
• 由来する生物種: Bungarus candidus
• 細胞内の位置: Secreted: P81782
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7293.41

構造登録者

Torres, A.M.,Kini, R.M.,Nirthanan, S.,Kuchel, P.W. (登録日: 2001-04-25, 公開日: 2001-12-21, 最終更新日: 2024-10-16)

主引用文献

Torres, A.M.,Kini, R.M.,Selvanayagam, N.,Kuchel, P.W.
NMR structure of bucandin, a neurotoxin from the venom of the Malayan krait (Bungarus candidus).
Biochem.J., 360:539-548, 2001

PubMed Abstract: A high-resolution solution structure of bucandin, a neurotoxin from Malayan krait (Bungarus candidus), was determined by (1)H-NMR spectroscopy and molecular dynamics. The average backbone root-mean-square deviation for the 20 calculated structures and the mean structure is 0.47 A (1 A=0.1 nm) for all residues and 0.24 A for the well-defined region that spans residues 23-58. Secondary-structural elements include two antiparallel beta-sheets characterized by two and four strands. According to recent X-ray analysis, bucandin adopts a typical three-finger loop motif and yet it has some peculiar characteristics that set it apart from other common alpha-neurotoxins. The presence of a fourth strand in the second antiparallel beta-sheet had not been observed before in three-finger toxins, and this feature was well represented in the NMR structure. Although the overall fold of the NMR structure is similar to that of the X-ray crystal structure, there are significant differences between the two structures that have implications for the pharmacological action of the toxin. These include the extent of the beta-sheets, the conformation of the region spanning residues 42-49 and the orientation of some side chains. In comparison with the X-ray structure, the NMR structure shows that the hydrophobic side chains of Trp(27) and Trp(36) are stacked together and are orientated towards the tip of the middle loop. The NMR study also showed that the two-stranded beta-sheet incorporated in the first loop, as defined by residues 1-22, and the C-terminus from Asn(59), is probably flexible relative to the rest of the molecule. On the basis of the dispositions of the hydrophobic and hydrophilic side chains, the structure of bucandin is clearly different from those of cytotoxins.

PubMed: 11736642
DOI: 10.1042/0264-6021:3600539

実験手法

SOLUTION NMR