Carbohydrate induced modulation of cell membrane. I. Interaction of sialic acid with peripheral blood lymphocytes: a spin label study.
Sialic acid is now known to serve as ligand for lymphocyte lectins known as selectins. Although its role as a ligand for adhesion molecules has been studied extensively, no studies have been performed to determine the physiological changes in lymphocytes after binding of sialic acid to lymphocyte lectin. We report for the first time that interaction of lymphocytes with sialic acid severely restricts the rotational mobility of the cell surface proteins as well as membrane lipids, as studied by EPR spectroscopy using spin probes. Binding of mucin totally immobilizes the lymphocyte membrane. Surprisingly the binding of sialic acid or mucin also immobilized the aqueous probe TEMPO, indicating an appreciable increase in cytoplasmic viscosity.
School of Life Sciences, Devi Ahilya Vishwavidyalaya, Vigyan Bhawan, Indore, India.
K
K
Hajela
R
R
Kayestha
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P
Kumar
D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D006041:Goats / Q000097:blood; D008051:Lipid Bilayers / Q000378:metabolism; D008214:Lymphocytes / Q000502:physiology / Q000648:ultrastructure*; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology; D009077:Mucins / Q000097:blood; D019158:N-Acetylneuraminic Acid; D012794:Sialic Acids / Q000097:blood*; D013113:Spin Labels
D003497:Cyclic N-Oxides; D008051:Lipid Bilayers; D008563:Membrane Lipids; D008565:Membrane Proteins; D009077:Mucins; D012794:Sialic Acids; D013113:Spin Labels; D019158:N-Acetylneuraminic Acid; C003959:TEMPO