Fig. 6

Representative CID spectrum over m/z 50–1050 of PAX1’ with intact molecular ion at m/z = 1052.79. CID analyses were performed over a CE gradient from 20 to 60 eV at a CV of 15 V. The two structures above the spectrum show the fragments that would lead to the 513.4 and 668.5 product ions and their subsequent fragmentation. The R group for PAX1’ is (3R)-3-hydroxy tetradecanoyl and the side-chain of Lys³ links up to the carboxyl group of Lys⁷ to form the ring structure