Fig. 4.

LTQ CID spectra of carbonylated LPP and oxoLPP modified peptides. For detection of oxoLPP cell pellets were collected, derivatized with 7-(diethylamino)coumarin-3-carbohydrazide (CHH), lipids were extracted and analyzed by direct infusion ESI-LTQ-Orbitrap. (A) LTQ CID spectrum of CHH-derivatized 4-hydroxy-nonenal. For identification of oxoLPP-modified proteins, nuclear proteins were separated by SDS-PAGE, in-gel digested with trypsin and analyzed by nUPLC-ESI-LTQ-Orbitrap MS. LTQ CID spectra of peroxisome-proliferator-activated receptor-γ coactivator 1α OHE-modified peptide ³⁶¹SSVLTGGH_oxEERK_OHE³⁷¹ (B), histone acetyltransferases KAT6B HHE-modified peptide ⁹⁶¹EKLILSH_HHEMEKLK⁹⁷² (C), and hnRNP A/B HHE-modified peptide ¹⁵⁴GFGFVTFDDH_HNEDPVDKIVLQK¹⁷³ (D).