Kinetics of channel formation of gramicidins A and B in phospholipid vesicle membranes.
The thermal incorporation and channel formation of gramicidins A and B into phosphatidylcholine/phosphatidylglycerol large unilamellar vesicle membranes was studied using 23Na NMR. Delta H and delta S of activation for channel formation for gramicidin A are 11.8 kcal/mol and -11 e.u., respectively. For gramicidin B, delta H and delta S of activation are 14.6 kcal/mol and -4 e.u., respectively. Possible reasons for the differences in delta H and delta S of activation between the two analogues are discussed.
Easton
P L
PL
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville 72701.
Hinton
J F
JF
Newkirk
D K
DK
D006096:Gramicidin; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D008051:Lipid Bilayers; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008433:Mathematics; D008954:Models, Biological; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D012964:Sodium
D007473:Ion Channels; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D006096:Gramicidin; D012964:Sodium