title: A GTP affinity probe for proteomics highlights flexibility in purine nucleotide selectivity.
abstract: GTP affinity probes are important tools for the study of GTP-binding proteins, and proteomic profiling is a powerful methodology well suited for the study of such a diverse class of proteins. Here, we synthesize and characterize a photoreactive GTP affinity probe that covalently photocross-links to protein targets and has an alkyne handle for click chemistry conjugation to reporter tags. The GTP-BP-yne probe facilitated identification of a variety of GTP-binding proteins by mass spectrometry, such as small GTPases and members of the GTP1/OBG family. Several ATP-binding proteins were also identified, highlighting variability in purine nucleotide selectivity of some proteins, and the probe was used to elucidate targets' relative nucleotide selectivities. The GTP-BP-yne probe will be a useful tool for the study of GTP-binding proteins, especially when targets of interest are not known a priori.
authors.affiliation: The Department of Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: George Cisar
authors.forename: Nhan
authors.initials: N
authors.lastname: Nguyen
authors.forename: Hugh
authors.initials: H
authors.lastname: Rosen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000345:Affinity Labels / Q000737:chemistry* / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000737:chemistry* / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D011485:Protein Binding; D040901:Proteomics; D011685:Purine Nucleotides / Q000378:metabolism
chemical_list: D000345:Affinity Labels; D011685:Purine Nucleotides; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D019204:GTP-Binding Proteins