Influence of the nature of the aromatic side-chain on the conductance of the channel of linear gramicidin: study of a series of 9,11,13,15-Tyr(O-protected) derivatives.
This paper describes the single channel properties of a series of synthetic analogues of gramicidin A, where all four tryptophans are replaced either by tyrosine or by several O-protected (benzyl, methyl, ethyl or t-butyl) derivatives. It is shown that, although all analogues bear similar dipole moment on their side-chains, the conductance depends on the hydrophobicity of these protecting groups. An analysis of the conductance data suggests that the conductance is governed by the binding process and a possible explanation, based on conformational considerations, is proposed.
Benamar
D
D
CRBM, CNRS/INSERM, Montpellier, France.
Daumas
P
P
Trudelle
Y
Y
Calas
B
B
Bennes
R
R
Heitz
F
F
D000595:Amino Acid Sequence; D004553:Electric Conductivity; D006096:Gramicidin / Q000737:chemistry*; D007473:Ion Channels / Q000737:chemistry / Q000502:physiology; D008563:Membrane Lipids / Q000737:chemistry / Q000502:physiology; D008566:Membranes / Q000737:chemistry / Q000502:physiology; D008969:Molecular Sequence Data; D013329:Structure-Activity Relationship; D014364:Tryptophan / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry*
D007473:Ion Channels; D008563:Membrane Lipids; D006096:Gramicidin; D014443:Tyrosine; D014364:Tryptophan