Site-Specific Protein Lipoylation Analysis via Aldehyde-Acetal Probe Labelling and Reversible Enrichment (DA-Lipo)

Abstract

Protein lipoylation regulates metabolic processes closely related to cancer and neurodegeneration, while only five human lipoylated proteins are identified, underscoring the need for robust analytical methods. We present DA-Lipo, a one-step labeling/enrichment strategy for site-specific lipoylation analysis. Terephthalaldehyde selectively tags lipoyl-peptides via cyclic thiol-aldehyde chemistry, enabling reversible enrichment and MS detection with a diagnostic immonium ion (419.18 Da). DA-Lipo confirmed known sites and revealed a novel lipoylation in GSTP2, offering a robust tool for functional studies.