gsk-2126458 and idelalisib

Until recently, one of the major limitations of hydrogen/deuterium exchange mass spectrometry (HDX-MS) was the peptide-level resolution afforded by proteolytic digestion. This limitation can be selectively overcome through the use of electron-transfer dissociation to fragment peptides in a manner that allows the retention of the deuterium signal to produce hydrogen/deuterium exchange tandem mass spectrometry (HDX-MS/MS). Here, we describe the application of HDX-MS/MS to structurally screen inhibitors of the oncogene phosphoinositide 3-kinase catalytic p110α subunit. HDX-MS/MS analysis is able to discern a conserved mechanism of inhibition common to a range of inhibitors. Owing to the relatively minor amounts of protein required, this technique may be utilised in pharmaceutical development for screening potential therapeutics.

Topics: Antineoplastic Agents; Binding Sites; Class I Phosphatidylinositol 3-Kinases; Class Ia Phosphatidylinositol 3-Kinase; Deuterium Exchange Measurement; Drug Evaluation, Preclinical; Electron Transport; Enzyme Inhibitors; Humans; Indazoles; Models, Molecular; Molecular Weight; Oligonucleotides; Peptide Fragments; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Conformation; Purines; Pyridazines; Quinazolinones; Quinolines; Recombinant Fusion Proteins; Reproducibility of Results; Signal Processing, Computer-Assisted; Sulfonamides; Tandem Mass Spectrometry; Triazines