1NT6

F1-Gramicidin C In Sodium Dodecyl Sulfate Micelles (NMR)

1NT6 の概要

• エントリーDOI: 10.2210/pdb1nt6/pdb
• 関連するPDBエントリー: 1AL4 1ALX 1ALZ 1AV2 1BDW 1C4D 1GMK 1GRM 1JNO 1JO3 1JO4 1KQE 1MAG 1MIC 1NG8 1NRM 1NRU 1NT5 1TK2 1TKQ 1W5U 2IZQ 2XDC 3L8L
• 関連するBIRD辞書のPRD_ID: PRD_001128
• 分子名称: GRAMICIDIN C (1 entity in total)
• 機能のキーワード: gramicidin, antifungal, antibacterial, sds micelles, membrane ion channel, linear gramicidin, antibiotic
• 由来する生物種: BREVIBACILLUS BREVIS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 3814.60

構造登録者

Townsley, L.E.,Fletcher, T.G.,Hinton, J.F. (登録日: 2003-01-28, 公開日: 2003-02-11, 最終更新日: 2024-10-30)

主引用文献

Sham, S.S.,Shobana, S.,Townsley, L.E.,Jordan, J.B.,Fernandez, J.Q.,Andersen, O.S.,Greathouse, D.V.,Hinton, J.F.
The Structure, Cation Binding, Transport, and Conductance of Gly15-Gramicidin a Incorporated Into Sds Micelles and Pc/Pg Vesicles.
Biochemistry, 42:1401-, 2003

PubMed Abstract: To further investigate the effect of single amino acid substitution on the structure and function of the gramicidin channel, an analogue of gramicidin A (GA) has been synthesized in which Trp(15) is replaced by Gly in the critical aqueous interface and cation binding region. The structure of Gly(15)-GA incorporated into SDS micelles has been determined using a combination of 2D-NMR spectroscopy and molecular modeling. Like the parent GA, Gly(15)-GA forms a dimeric channel composed of two single-stranded, right-handed beta(6.3)-helices joined by hydrogen bonds between their N-termini. The replacement of Trp(15) by Gly does not have a significant effect on backbone structure or side chain conformations with the exception of Trp(11) in which the indole ring is rotated away from the channel axis. Measurement of the equilibrium binding constants and Delta G for the binding of monovalent cations to GA and Gly(15)-GA channels incorporated into PC vesicles using (205)Tl NMR spectroscopy shows that monovalent cations bind much more weakly to the Gly(15)-GA channel entrance than to GA channels. Utilizing the magnetization inversion transfer NMR technique, the transport of Na(+) ions through GA and Gly(15)-GA channels incorporated into PC/PG vesicles has been investigated. The Gly(15) substitution produces an increase in the activation enthalpy of transport and thus a significant decrease in the transport rate of the Na(+) ion is observed. The single-channel appearances show that the conducting channels have a single, well-defined structure. Consistent with the NMR results, the single-channel conductances are reduced by 30% and the lifetimes by 70%. It is concluded that the decrease in cation binding, transport, and conductance in Gly(15)-GA results from the removal of the Trp(15) dipole and, to a lesser extent, the change in orientation of Trp(11).

PubMed: 12578352
DOI: 10.1021/BI0204286

実験手法

SOLUTION NMR