TI-205 nuclear magnetic resonance determination of the thermodynamic parameters for the binding of monovalent cations to gramicidins A and C.
Thermodynamic parameters for the binding of the monovalent cations, Li+, Na+, K+, Rb+, Cs+, NH4+, TI+, and Ag+, to gramicidin A and for the binding of TI+ to gramicidin C, incorporated into lysophosphatidylcholine, have been determined using a combination of TI-205 nuclear magnetic resonance spectroscopy and competition binding. The thermodynamic parameters, enthalpy and entropy, are discussed in terms of a process involving the transfer of cations from an aqueous to amide environment.
Hinton
J F
JF
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville 72701.
Fernandez
J Q
JQ
Shungu
D C
DC
Whaley
W L
WL
Koeppe
R E
RE
Millett
F S
FS
D006096:Gramicidin / Q000378:metabolism*; D007473:Ion Channels / Q000502:physiology*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008954:Models, Biological; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D013793:Thallium; D013816:Thermodynamics
D007473:Ion Channels; D006096:Gramicidin; D013793:Thallium