title: Ligand binding affinity and changes in the lateral diffusion of receptor for advanced glycation endproducts (RAGE).
abstract: The effect of ligand on the lateral diffusion of receptor for advanced glycation endproducts (RAGE), a receptor involved in numerous pathological conditions, remains unknown. Single particle tracking experiments that use quantum dots specifically bound to hemagglutinin (HA)-tagged RAGE (HA-RAGE) are reported to elucidate the effect of ligand binding on HA-RAGE diffusion in GM07373 cell membranes. The ligand used in these studies is methylglyoxal modified-bovine serum albumin (MGO-BSA) containing advanced glycation end products modifications. The binding affinity between soluble RAGE and MGO-BSA increases by 1.8 to 9.7-fold as the percent primary amine modification increases from 24 to 74% and with increasing negative charge on the MGO-BSA. Ligand incubation affects the HA-RAGE diffusion coefficient, the radius of confinement, and duration of confinement. There is, however, no correlation between MGO-BSA ligand binding affinity with soluble RAGE and the extent of the changes in HA-RAGE lateral diffusion. The ligand induced changes to HA-RAGE lateral diffusion do not occur when cholesterol is depleted from the cell membrane, indicating the mechanism for ligand-induced changes to HA-RAGE diffusion is cholesterol dependent. The results presented here serve as a first step in unraveling how ligand influences RAGE lateral diffusion.
authors.affiliation: Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, IA 50011, United States.
authors.forename: Aleem
authors.initials: A
authors.lastname: Syed
authors.affiliation: Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, IA 50011, United States.
authors.forename: Qiaochu
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, IA 50011, United States. Electronic address: esmith1@iastate.edu.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Smith
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004058:Diffusion; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D008024:Ligands; D045663:Quantum Dots; D000067759:Receptor for Advanced Glycation End Products / Q000737:chemistry / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D008024:Ligands; D000067759:Receptor for Advanced Glycation End Products; D012710:Serum Albumin, Bovine; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Cholesterol depletion; Fluorescence microscopy; Membrane biophysics; Receptor signaling; Single particle tracking