1OMB

SEQUENTIAL ASSIGNMENT AND STRUCTURE DETERMINATION OF SPIDER TOXIN OMEGA-AGA-IVB

1OMB の概要

• エントリーDOI: 10.2210/pdb1omb/pdb
• 分子名称: OMEGA-AGA-IVB (1 entity in total)
• 機能のキーワード: toxin
• 由来する生物種: Agelenopsis aperta
• 細胞内の位置: Secreted: P37045
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 5287.13

構造登録者

Yu, H.,Rosen, M.K.,Schreiber, S.L. (登録日: 1993-09-09, 公開日: 1993-10-31, 最終更新日: 2024-10-30)

主引用文献

Yu, H.,Rosen, M.K.,Saccomano, N.A.,Phillips, D.,Volkmann, R.A.,Schreiber, S.L.
Sequential assignment and structure determination of spider toxin omega-Aga-IVB.
Biochemistry, 32:13123-13129, 1993

PubMed Abstract: The solution structure of a peptide toxin isolated from funnel web spider venom, omega-Aga-IVB, was determined by 2D NMR methods. omega-Aga-IVB is a high-affinity specific blocker of P-type voltage-dependent calcium channels. Nearly all of the proton resonances of this 48-residue protein were assigned using conventional 2D homonuclear NMR experiments. The three-dimensional structure of the molecule was determined by simulated annealing. The distance and dihedral restraints used in the structure calculations were derived from NOESY and COSY-type experiments, respectively. Mass spectrometric analysis of omega-Aga-IVB suggests that the protein contains four disulfide bonds. In the absence of chemical data to identify the pattern of cysteine pairing, the disulfide bonds of the toxin are proposed from the NMR data and subsequent structural calculations. The structure of the toxin can be described as a three-stranded anti-parallel beta sheet connected by flexible loops. A striking feature of the structure is that the C-terminal 10 residues of this protein adopt random coil conformations. Several positively charged amino acid side chains are found localized on one face of the molecule, in close proximity to the C-terminal tail. This observation has led us to propose a speculative model of the toxins blockade mechanism.

PubMed: 8241166
DOI: 10.1021/bi00211a022

実験手法

SOLUTION NMR