Journal of Lipid Research, Vol 31, 947-951, Copyright © 1990 by Lipid Research, Inc.
Critical self-association of bile lipids studied by infrared spectroscopy and viscometry
L Antonian, S Deb and W Spivak
Department of Pediatrics, Cornell University Medical College, New York, NY 10021.
Fourier transform infrared (FTIR)-attenuated total reflection (ATR)
spectroscopy and viscometry were applied to study the micellization of two
bile lipids, sodium taurochenodeoxycholate (NaTCDC) and sodium glycocholate
(NaGC), in aqueous solutions. The CH2 stretching bands of the bile lipid
hydrocarbon region were shifted to higher frequencies suggesting initial
critical micellization at 2.5 mM for NaTCDC and 9 mM for NaGC. An abrupt
enhancement of the absorption intensity of the CH3 groups of the sterol
rings in bile lipids were under conformational strain at 3.5 mM NaTCDC and
9 mM NaGC. Viscometry measurements showed abrupt changes in viscosities in
the region of critical micellar concentration (CMC) of both bile lipids.
Both infrared and viscometry studies confirmed the onset of conformational
strains in tightly packed lipid micelles at their CMC. In addition,
FTIR/ATR spectroscopy has defined the specific hydrophobic interactions
which bring about critical micellization of bile lipids.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
