Chemical Proteomic Profiling of Lysophosphatidic Acid-Binding Proteins

Anal Chem. 2019 Dec 17;91(24):15365-15369. doi: 10.1021/acs.analchem.9b04850. Epub 2019 Nov 27.

Abstract

Lysophosphatidic acid (LPA) is an endogenous cell signaling molecule, and dysregulation of LPA signaling pathways is accompanied by several types of cancer. Herein, we developed a chemical proteomic method for the proteome-wide identification of LPA-binding proteins. The method involves the synthesis of a desthiobiotin-conjugated LPA acyl phosphate probe for the covalent labeling, enrichment, and subsequent LC-MS/MS identification of LPA-binding proteins at the proteome-wide level. By conducting labeling reactions at two different probe concentrations (10 and 100 μM) in conjunction with an SILAC (stable isotope labeling by amino acids in cell culture)-based workflow, we characterized the LPA-binding capabilities of these proteins at the entire proteome scale, which led to the identification of 86 candidate LPA-binding proteins in HEK293T cells. Moreover, we validated that two of these proteins, annexin A5 and phosphoglycerate kinase 1, can bind directly with LPA. Together, we developed a novel LPA probe for the identification and characterizations of LPA-binding proteins from the entire human proteome. The method should be adaptable for the identification of other lipid-binding proteins.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Extracts
  • HEK293 Cells
  • Humans
  • Lysophospholipids / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Protein Binding
  • Protein Conformation
  • Proteomics*

Substances

  • Cell Extracts
  • Lysophospholipids
  • lysophosphatidic acid