TITLE:
Structural Change in Dimyristoyl Phosphatidyl Choline (DMPC) Molecule Alkyl Chains on the Addition of Cholesterol to DMPC Monolayer: Specific Addition Effect of Cholesterol
AUTHORS:
Daiki Ito, Takanari Ikeda, Keijiro Taga, Yasushi Yamamoto, Zameer Shervani, Masato Yamamoto
KEYWORDS:
Dimyristoyl Phosphatidyl Choline (DMPC), Cholesterol, Surface Tension Measurement (STm), Brewster Angle Microscopy (BAM), Infrared External Reflection Microscopy (IERS), Structural Transition
JOURNAL NAME:
Journal of Biophysical Chemistry,
Vol.10 No.2,
May
28,
2019
ABSTRACT: We have investigated the morphology of dimyristoyl phosphatidyl choline
(DMPC)—cholesterol mixed monolayer formed on
the water surface by dropping method using surface tension measurement
(STm), Brewster angle microscopy (BAM), and infrared external reflection
spectroscopy (IERS). STm results showed negative deviation of the limiting
molecular area (A0) of cholesterol
occurred when cholesterol was added to the DMPC monolayer. BAM images showed
the expandable DMPC monolayer changed to the condensed rigid monolayer at more
than cholesterol mole fraction (xChol)
0.4. IERS recordings showed that the addition of cholesterol at xChol = 0.4 occurred structural
change from gauche- to trans- conformation
of two DMPC molecule alkyl chains. From these
results, it is found that cholesterol molecule has specific properties
that cause structural transition of DMPC molecule alkyl chains.