Rotational dynamics of erythrocyte spectrin.
The rotational diffusion of erythrocyte spectrin has been measured using time-resolved phosphorescence anisotropy. The anisotropy of the spectrin dimer decays to zero with a time constant of 3 microseconds at 21 degrees C. The results are compared with the correlation times predicted for the anisotropy decay of an equivalent sphere and rigid rod. The data indicate that the ribbon-like spectrin molecule possesses considerable torsional and segmental flexibility. These motions are restricted, but not abolished, when spectrin is reconstituted into cross-linked cytoskeletal protein networks, or bound to spectrin-actin depleted erythrocyte membrane vesicles.
Learmonth
R P
RP
Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Australia.
Woodhouse
A G
AG
Sawyer
W H
WH
D000199:Actins / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004058:Diffusion; D004912:Erythrocytes / Q000032:analysis*; D005456:Fluorescent Dyes; D006801:Humans; D046911:Macromolecular Substances; D009994:Osmolar Concentration; D013049:Spectrin / Q000378:metabolism; D013050:Spectrometry, Fluorescence
D000199:Actins; D005456:Fluorescent Dyes; D046911:Macromolecular Substances; D013049:Spectrin