title: Labeling phosphorylated LHCII with microspheres for tracking studies and force measurements.
abstract: We report a method to selectively label phosphorylated, membrane proteins with microscopic particles. This technology is particularly useful in single particle studies. In such studies, the particles may serve to visualize protein diffusion and/or as 'handles' to study the force of interaction between the labeled protein and the membrane matrix. In the latter kind of experiments, forces can be applied and measured by calibrated optical tweezers. Optical tweezers were used in this work to test the strength of the particle labeling. Labeling a single protein with a particle produces a long-lived, distinct tag and is particularly useful for proteins in photosynthetic membranes, which contain endogenous fluorophores that would render single fluorescent proteins difficult to detect.
authors.affiliation: Dipartimento di Biologia, Università di Milano, 20133 Milano, Italy. laura.finzi@unimi.it
authors.forename: L
authors.initials: L
authors.lastname: Finzi
authors.forename: P
authors.initials: P
authors.lastname: Galajda
authors.forename: G
authors.initials: G
authors.lastname: Garab
mesh_terms: D002736:Chloroplasts / Q000378:metabolism; D008863:Microspheres; D010766:Phosphorylation; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D018724:Spinacia oleracea / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods; D020524:Thylakoids / Q000378:metabolism
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins