Fig. 2: Verification of Kmea structure by ozone (O3) oxidation.

a, b Chemical reactions for ozonolysis of the double bonds in Kmea (a) and Kcr (b) peptides. c MS/MS of ozonolyzed peptides. The synthetic H2AK95mea peptide, NDEELNKmeaLLGK, was subjected to ozonolysis reaction. Its main reaction product, NDEELNK+70LLGK, was analyzed by HPLC/MS/MS analysis. d MS/MS of a NDEELNK +70LLGK peptide detected in O3 oxidized HeLa histone extract.