1MTX

DETERMINATION OF THE THREE-DIMENSIONAL STRUCTURE OF MARGATOXIN BY 1H, 13C, 15N TRIPLE-RESONANCE NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

1MTX の概要

• エントリーDOI: 10.2210/pdb1mtx/pdb
• 分子名称: MARGATOXIN (1 entity in total)
• 機能のキーワード: toxin
• 由来する生物種: Centruroides margaritatus
• 細胞内の位置: Secreted: P40755
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 4192.05

構造登録者

Johnson, B.A.,Stevens, S.P.,Williamson, J.M. (登録日: 1994-12-27, 公開日: 1995-11-14, 最終更新日: 2024-10-30)

主引用文献

Johnson, B.A.,Stevens, S.P.,Williamson, J.M.
Determination of the three-dimensional structure of margatoxin by 1H, 13C, 15N triple-resonance nuclear magnetic resonance spectroscopy.
Biochemistry, 33:15061-15070, 1994

PubMed Abstract: The solution structure of the 39-residue peptide margatoxin, a scorpion toxin that selectively blocks the voltage-gated potassium-channel Kv1.3, has been determined by NMR spectroscopy. The toxin was isotopically labeled with 13C and 15N and studied using two-dimensional homonuclear and three- and four-dimensional heteronuclear NMR spectroscopy. The final structure was determined using 501 constraints, comprising 422 NOE constraints, 60 dihedral angle constraints, 9 disulfide constraints, and 10 hydrogen bond constraints. Structures were initially determined with the program PEGASUS and subsequently refined with X-PLOR. The average rms deviation from a calculated average structure for the backbone atoms of residues 3-38 is 0.40 A. A helix is present from residues 11 to 20 and includes two proline residues at positions 15 and 16. A loop at residues 21-24 leads into a two-strand antiparallel sheet from residues 25 to 38 with a turn at residues 30-33. Residues 3-6 run adjacent to the 33-38 strand but do not form a canonical beta-strand. The two additional residues of margatoxin, relative to the related toxins charybdotoxin and iberiotoxin, insert in a manner that extends the beta-sheet by one residue. Otherwise, the global structure is very similar to that of these two other toxins. The longer sheet may have implications for channel selectivity.

PubMed: 7999764
DOI: 10.1021/bi00254a015

実験手法

SOLUTION NMR