Utilizing a Simple Method for Stoichiometric Protein Labeling to Quantify Antibody Blockade.

ABSTRACT: Ligand binding assays routinely employ fluorescently-labeled protein ligands to quantify the extent of binding. These ligands are commonly generated through chemical modification of accessible lysine residues, which often results in heterogeneous populations exhibiting variable binding properties. This could be remedied by quantitative, site-specific labeling. Recently, we reported on a single-step method integrating recombinant protein purification with 2-cyanobenzothiazole (CBT) condensation for labeling a proteolytically exposed N-terminal cysteine. Here, using three growth factors, we show that unlike random lysine labeling, this site-specific approach yielded homogeneous populations of growth factors that were quantitatively labeled at their N-termini and retained their binding charac

SUBMITTER: Friedman Ohana R 

PROVIDER: S-EPMC6504924 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature