STP863

    Global and Nonglobal Rotations in Proteins Detected by Fluorescence Polarization

    Published: Jan 1985


      Format Pages Price  
    PDF (236K) 14 $25   ADD TO CART
    Complete Source PDF (1.7M) 14 $55   ADD TO CART


    Abstract

    Fluorescence polarization methods have been used to assess protein motion for about three decades. These methods are still evolving, but basically can be divided into three classes: (1) steady state methods, (2) time-resolved anisotropy measurement, and (3) differential polarized phase fluorometry. A brief overview of these methods is given, and data are presented on proteins that are unlabeled, or conjugated with dansyl (1-dimethylaminonaphthalene-5-sulfonyl) group. The experiments show that the dansyl label exhibits a fast thermally activated motion, which is viscosity independent, as well as a slower motion characteristic of the global rotation of the protein as a whole. Data on the intrinsic ultraviolet fluorescence of proteins show that the global rotation rate can be obtained from steady state data, which also can detect independent motion of the tryptophan residues. Time-resolved anisotropy data are presented showing directly the rapid rotation of the dansyl group. These data illustrate the ease with which polarization data detect global and nonglobal rotations in proteins.

    Keywords:

    proteins, fluorescence, molecular relaxation, protein fluorescence, fluorescence polarization, fluorescence anisotropy, protein flexibility, Perrin plot, dansyl fluorescence, tryptophan fluorescence, fluorescence lifetime


    Author Information:

    Chen, RF
    Medical officer and biologist, National Heart, Lung, and Blood Institute, Bethesda, MD

    Scott, CH
    Medical officer and biologist, National Heart, Lung, and Blood Institute, Bethesda, MD


    Paper ID: STP32769S

    Committee/Subcommittee: E13.06

    DOI: 10.1520/STP32769S


    CrossRef ASTM International is a member of CrossRef.