Synergistic Interactions of Sugars/Polyols and Monovalent Salts with Phospholipids Depend upon Sugar/Polyol Complexity and Anion Identity.
We found that interactions of dipalmitoylphosphatidylcholine (DPPC) lipid monolayers with sugars are influenced by addition of NaCl. This work is of general importance in understanding how sugar-lipid-salt interactions impact biological systems. Using Langmuir isothermal compressions, fluorescence microscopy, atomic force microscopy, and neutron reflectometry, we examined DPPC monolayers upon addition of sugars/polyols and/or monovalent salts. Sugar-lipid interactions in the presence of NaCl increased with increasing complexity of the sugar/polyol in the order glycerol ≪ glucose < trehalose. When the anion was altered in the series NaF, NaCl, and NaBr, only minor differences were observed. When comparing LiCl, NaCl, and KCl, sodium chloride had the greatest influence on glucose and trehalose interactions with DPPC. We propose that heterogeneity created by cation binding allows for sugars to bind the lipid headgroups. While cation binding increases in the order K(+) < Na(+) < Li(+), lithium ions may also compete with glucose for binding sites. Thus, both cooperative and competitive factors contribute to the overall influence of salts on sugar-lipid interactions.
Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States.
Ginevra A
GA
Clark
Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States.
J Michael
JM
Henderson
Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States.
Charles
C
Heffern
Department of Chemistry, Bogazici University , Bebek, Istanbul 34342, Turkey.|National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States.|Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742, United States.
Bülent
B
Akgün
Los Alamos Neutron Scattering Center/MPA/CINT, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.|Department of Chemical Engineering, University of California , Davis, California 95616, United States.
Jaroslaw
J
Majewski
Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States.
Ka Yee C
KY
Lee
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D005990:Glycerol / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D013237:Stereoisomerism; D014199:Trehalose / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine; D012965:Sodium Chloride; D014199:Trehalose; D005947:Glucose; D005990:Glycerol