Ion channels from linear and branched bola-amphiphiles

被引:36
作者
Eggers, PK [1 ]
Fyles, TM [1 ]
Mitchell, KDD [1 ]
Sutherland, T [1 ]
机构
[1] Univ Victoria, Dept Chem, Victoria, BC V8W 3P6, Canada
关键词
D O I
10.1021/jo026415f
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
The synthesis and characterization of the ion channel activity of three new bola-amphiphiles is described. These compounds are conceptually derived from a previously reported bis-cyclophane bola-amphiphile through opening of the cyclophanes to acyclic structures and were found to readily form ion channels in planar bilayer membranes as assessed by bilayer clamp single-channel analysis. All three compounds behaved very similarly: the dominant channels formed by all three are Ohmic with specific conductance of 10 +/- 1 pS (NaCl electrolyte) and 39 +/- 1 pS (CsCl electrolyte). Singleion permeability ratios, determined from dissymmetric electrolyte experiments, showed the selectivity P(Cs+) > P(Na+) > P(Cl-). Less frequently, lower conductance channels were also observed to act independently of the dominant channels. The lifetimes of the dominant channels range from 70 to 280 ms for the three compounds with some very long-lived openings (20-40 s) observed for two of the three. The lower conductance states have shorter lifetimes. This study demonstrates that bis-macrocyclic compounds are not essential for channel formation by bola-amphiphiles, and opens a new class of channel-forming compounds for structure- activity optimization.
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页码:1050 / 1058
页数:9
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