Measurement of the translational mobility of concanavalin A in glycerol-saline solutions and on the cell surface by fluorescence recovery after photobleaching.
The fluorescence recovery kinetics of succinyl-fluorescein Concanavalin A (S-F-ConA) in glycerol-physiological saline solutions of high viscosity and when bound to the surface of mouse fibroblasts were measured following brief photobleaching using a laser excited fluorescence microscope. In the high viscosity solutions, the recovery kinetics, interpreted on the basis of a simple diffusion model, yielded a diffusion coefficient in close agreement with the values predicted by the Stokes-Einstein equation. Recovery kinetics for S-F-ConA bound to the surface of mouse 3T3 and SV3T3 cells cultured in vitro yielded diffusion coefficients in the range of 5-10-10(-11) cm2/s, values considerably lower than those reported previously for membrane proteins. These measurements indicated that a considerable fraction of the S-F-ConA molecules bound to the cell surface are immobilized. These results are discussed in relation to current concepts of lateral motion of protein components within natural membranes.
D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic; D003208:Concanavalin A / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism*; D007700:Kinetics; D007739:L Cells / Q000378:metabolism; D007834:Lasers; D008433:Mathematics; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism; D013539:Simian virus 40 / Q000378:metabolism; D012965:Sodium Chloride; D013050:Spectrometry, Fluorescence
D011506:Proteins; D003208:Concanavalin A; D012965:Sodium Chloride; D005990:Glycerol