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, but only five human lipoylated proteins have been identified, underscoring the need for robust analytical methods. We present DA-Lipo, a one-step labelling/enrichment strategy for site-specific lipoylation analysis. Terephthalaldehyde monodiethylacetal 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.