Journal: PLOS One

Article Title: Mechanistic studies of PFKFB2 reveal a novel inhibitor of its kinase activity

doi: 10.1371/journal.pone.0317167

Figure Lengend Snippet: (A) Western blot analysis of cleared bacterial lysates of GST-PFKFB2 and mutants. Top: Total protein staining of cleared bacterial lysates over-expressing GST-PFKFB2 and mutants. Bottom: Western blots against GST and phosphorylated-PFKFB2 (Ser483) for GST-PFKFB2 and mutants. “Double mut” indicates protein containing both K174G and H259A. (B) Western blot analysis of GST-PFKFB2 expression, purification, and in vitro phosphorylation. Flow thru indicates proteins unbound to GSH beads. Column are proteins bound to the GSH beads. Column + Thrombin are proteins remaining bound to GSH beads after thrombin cleavage. Purified PFK2 lanes are proteins eluted from the GSH beads with thrombin cleavage. Purified PFK2 + ATP are proteins incubated with ATP alone. Purified PFK2 + ATP + PKA are proteins phosphorylated by PKA. (C) Western blot analysis of GST-PFKFB2 and mutant proteins showing they are phosphorylated (Ser483) upon extraction from bacteria ( left lanes ), lose phosphorylation after purification ( middle lanes ), but are re-phosphorylated upon treatment with PKA and ATP ( right lanes ). (D) Representative western blot against phosphorylated-PFKFB2 (Ser483) of bacterial samples (WT PFKFB2) treated/not treated with λ-phosphatase for indicated times before lysis. Equal amounts of purified PFKFB2 were treated and loaded into each lane. Quantitation of bacterial samples treated with λ-phosphatase. Data are shown as mean±SD. The original, unedited blots are included in .

Article Snippet: Assay conditions were 100 µL sonicated sample, 10 µL MnCl 2 (10 mM NEB), 10 µL phosphatase buffer (10x PMP buffer, NEB) with or without 2 µL Lambda protein phosphatase (NEB, 400000 U/mL).

Techniques: Western Blot, Staining, Expressing, Purification, In Vitro, Phospho-proteomics, Incubation, Mutagenesis, Extraction, Bacteria, Lysis, Quantitation Assay