Effect of inserted oxysterols on phospholipid packing in normal and sickle red blood cell membranes

• Published in: Biochemical and biophysical research communications Vol. 180; no. 2; pp. 730 - 734
• Main Authors: Szostek, R., Kucuk, O., Lis, L.J., Tracy, D., Mata, R., Dey, T., Kauffman, J.W., Yachnin, S., Westerman, M.P.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 31.10.1991; Elsevier
• Subjects: Anemia, Sickle Cell - blood; Biological and medical sciences; Biological membranes; cell membranes; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - metabolism; Fourier Analysis; Fundamental and applied biological sciences. Psychology; Humans; Membrane Fluidity - drug effects; Membrane Lipids - blood; Membrane physicochemistry; Molecular biophysics; oxysterol; phospholipids; Phospholipids - blood; Reference Values; Spectrophotometry, Infrared - methods; Sterols - pharmacology; Incorporation; Plasma membrane; Red blood cell; Phospholipid; Sickle cell erythrocyte; Comparative study; Physicochemical properties
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(05)81126-X

Fourier transform infrared (FTIR) spectroscopy was used to examine the effect of oxysterol insertion into normal and sickle RBC membranes and the total lipid extracts of the membranes. Examination of the FTIR C-H stretch and fingerprint regions reveal that the insertion of 7α− and 7β-hydroxycholesterol has the greatest effect on the fluidity of RBC membranes and lipid extracts. The results confirm the observation that sterol molecules are oriented in the membrane so that the 7 position is located in the phospholipid head group region at the lipid/water interface. The substitution of a keto for a hydroxy group at the number seven position decreases the effect of the sterol on membrane packing.