6BUC

Structure of a new ShKT peptide from the sea anemone Oulactis sp.

6BUC の概要

• エントリーDOI: 10.2210/pdb6buc/pdb
• NMR情報: BMRB: 30378
• 分子名称: OspTx2b (1 entity in total)
• 機能のキーワード: osptx2b, nmr spectroscopy, bgk-like fold, venom peptide
• 由来する生物種: Oulactis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 3790.27

構造登録者

Krishnarjuna, B.,Norton, R.S. (登録日: 2017-12-10, 公開日: 2018-05-30, 最終更新日: 2024-10-09)

主引用文献

Krishnarjuna, B.,Villegas-Moreno, J.,Mitchell, M.L.,Csoti, A.,Peigneur, S.,Amero, C.,Pennington, M.W.,Tytgat, J.,Panyi, G.,Norton, R.S.
Synthesis, folding, structure and activity of a predicted peptide from the sea anemone Oulactis sp. with an ShKT fold.
Toxicon, 150:50-59, 2018

PubMed Abstract: Sea anemone venom is rich in bioactive compounds, including peptides containing multiple disulfide bridges. In a transcriptomic study on Oulactis sp., we identified the putative 36-residue peptide, OspTx2b, which is an isoform of the K channel blocker OspTx2a (Sunanda P et al. [2018] Identification, chemical synthesis, structure and function of a new K1 channel blocking peptide from Oulactis sp. Peptide Science, in press). As OspTx2b contains a ShK/BgK-like cysteine framework, with high amino acid sequence similarity to BgK, we were interested to investigate its structure and function. The solution structure of OspTx2b was determined using nuclear magnetic resonance spectroscopy. OspTx2b does indeed possess a BgK-like scaffold, with the same disulfide bond connectivities. The orientation of the Lys-Tyr dyad in OspTx2b is more similar to that in ShK than in BgK. However, it failed to show against a range of voltage-gated potassium channels in Xenopus oocytes and human T lymphocytes. OspTx2b also showed no growth inhibitory activity against several strains of bacteria and fungi. Having a BgK-like fold with the Lys-Tyr dyad but no BgK-like activity highlights the importance of key amino acid residues in BgK that are missing in OspTx2b. The lack of activity against the K channels assessed in this study emphasises that the ShK/BgK scaffold is capable of supporting functional activity beyond potassium channel blockade.

PubMed: 29772211
DOI: 10.1016/j.toxicon.2018.05.006

実験手法

SOLUTION NMR