Chiroptical rhythmicity, Part 2: Evidence for signal transduction by stereoselective ion pair formation at the membrane/water interface.
The initiation mechanism of chiroptical rhythmicity, a novel chiroptical phenomenon (Ghebremariam and Matile preceding contribution), was investigated by exploring the functionality of five structural analogs of the inducing L-His ligand. Disappearnace of chiroptical rhythmicity with L-His methyl esters as well as with D-His implied that stereoselective ion pair formation between carboxylate anion of L-His bound at the membrane/water interface and ammonium cations of phosphatidylcholine is essential for signal transduction to the hydrophobic core of the membrane. It was further shown that "H" aggregation of the asymmetric septi(p-phenylene) chromophore induced by multivalent L-His (i.e., poly-L-His) exceeds the extent required for chiroptical rhythmicity by far and ultimately results in the formation of achiral herringbone lattices.
Ghebremariam
B
B
Department of Chemistry, Georgetown University, Washington, DC 20057, USA.
Matile
S
S
D006639:Histidine / Q000031:analogs & derivatives / Q000737:chemistry*; D007477:Ions; D008051:Lipid Bilayers / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010713:Phosphatidylcholines / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014867:Water
D007477:Ions; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D014867:Water; D006639:Histidine