CHARACTERISTICS OF HIGH-ENERGY COLLISION-INDUCED DISSOCIATION TANDEM MASS-SPECTRA OF POLYCYCLIC AROMATIC HYDROCARBON DIOLEPOXIDE ADDUCTED PEPTIDES

Polycyclic aromatic hydrocarbon (PAH) diolepoxides are known to covale ntly modify serum albumin and hemoglobin. Mass spectrometric technique s have proven quite useful in the characterization of the site of addu ction on these proteins. To facilitate the study of PAH diolepoxide ad ducted peptides, model peptide adducts of benzo[a]pyrene-trans-7,8-dih ydrodiol-9,10-epoxide [anti-BaP(9,10)DE] and o[a]anthracene-trans-8,9- dihydrodiol-10,11-epoxide [anti-BaA(10,11)DE] have been synthesized fo r the purpose of studying their high energy collision-induced dissocia tion tandem mass spectra. These spectra are dominated by ions produced from cleavage of the peptide-adduct bond with charge retention by the adducting moiety. Such ions allow for the facile identification of ad ducted peptides in a mixture by use of neutral loss scans. The peptide sequence can still be deduced from the data in most cases and the sit e of adduction can be determined. For those peptide-adducts in which t his is not possible, a charged derivative placed at the N-terminus sim plifies the peptide fragmentation pattern and makes the spectrum more interpretable.