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Updated: Mar 14, 2026

Detection of Small GTPase Prenylation and GTP Binding Using Membrane Fractionation and GTPase-linked Immunosorbent Assay
Published on: November 11, 2018
Intrinsic protein fluorescence assays for GEF, GAP and post-translational modifications of small GTPases
1Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany.
Abstract:
Evidence and arguments are summarized that suggest that intrinsic (tryptophan) protein fluorescence provides an excellent and convenient signal for monitoring both GEF (guanine nucleotide exchange factor) and GAP (GTPase activating protein) activity of a large number of small GTPases. In addition, post-translational modifications of Rab proteins occurring in a region known to be a hot spot for such modifications also lead to fluorescence changes that can be accurately monitored in a time-dependent manner. It is suggested that intrinsic fluorescence should be the first method chosen for monitoring such reactions of tryptophan-containing small GTPases.
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