328273-17-2Relevant articles and documents
Fluorometric assay for tissue transglutaminase-mediated transamidation activity
Gnaccarini, Claudio,Ben-Tahar, Wajih,Lubell, William D.,Pelletier, Joelle N.,Keillor, Jeffrey W.
, p. 6354 - 6359 (2009)
Herein, we report the development of a direct discontinuous fluorometric transamidation assay for determining tissue transglutaminase (TG2) activity. In the assay reaction, TG2 catalyzes the formation of a biotin-fluorophore conjugate, using a fluorescent, high affinity γ-glutamyl donor substrate and a biotinylated amine as a γ-glutamyl acceptor substrate. After the reaction, the conjugate is fixed on streptavidin-coated beads and excess substrate is washed away, allowing the transamidation activity to be quantified by fluorescence measurement. This method was used to detect the activity of as little as 0.6 mU of purified TG2, and can be used for detection of activity from crude cellular lysates. Furthermore, this assay can be used for screening potential inhibitors and synthetic substrates, the latter of which was demonstrated herein.
PHOTOPROXIMITY PROFILING OF PROTEIN-PROTEIN INTERACTIONS IN CELLS
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Page/Page column 73; 77-78, (2021/04/01)
Photoactive probes and probe systems for detecting biological interactions are described. The photoactive probes include probes that combine both photocleavable and photoreactive moieties. The photoactive probe systems can include a first probe comprising a photocatalytic group and a second probe comprising a group that can act as a substrate for the reaction catalyzed by the photocatalytic group. The probes and probe systems can also include groups that can specifically bind to a binding partner on a biological entity of interest and a detectable group or a precursor thereof. The probes and probe systems can detect spatiotemporal interactions of proteins or cells. In some embodiments, the interactions can be detected in live cells. Also described are methods of detecting the biological interactions.
An improved synthesis of a fluorophosphonate-polyethylene glycol-biotin probe and its use against competitive substrates
Xu, Hao,Sabit, Hairat,Amidon, Gordon L.,Showalter, H.D. Hollis
, p. 89 - 96 (2013/03/13)
The fluorophosphonate (FP) moiety attached to a biotin tag is a prototype chemical probe used to quantitatively analyze and enrich active serine hydrolases in complex proteomes in an approach called activity-based protein profiling (ABPP). In this study we have designed a novel synthetic route to a known FP probe linked by polyethylene glycol to a biotin tag (FP-PEG-biotin). Our route markedly increases the efficiency of the probe synthesis and overcomes several problems of a prior synthesis. As a proof of principle, FP-PEG-biotin was evaluated against isolated protein mixtures and different rat-tissue homogenates, showing its ability to specifically target serine hydrolases. We also assessed the ability of FP-PEG-biotin to compete with substrates that have high enzyme turnover rates. The reduced protein-band intensities resulting in these competition studies demonstrate a new application of FP-based probes seldom explored before.