FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRIC ANALYSIS OF CYCLIC-NUCLEOTIDE ANALOGS USED IN STUDIES OF CYCLIC NUCLEOTIDE-DEPENDENT PROTEIN-KINASES

Three compounds, 8-(6-aminohexyl)-aminoadenosine-3',5'-cyclic monophos phate, N-6-benzyladenosine-3',5'-cyclic monophosphate and 8-piperidino adenosine-3',5'-cyclic monophosphate, known as potent activators of cy clic AMP-dependent protein kinase, produced positive-ion fast atom bom bardment (FAB) mass spectra with a strong quasimolecular ion. Collisio n-induced dissociation (CID) of these protonated molecules followed by mass-analysed ion kinetic energy (MIKE) spectrometry yielded spectra indicating fragmentation patterns similar to those of the unsubstitute d cyclic nucleotide, together with fragments resulting from cleavages within the substituent groups. These CID/MIKE spectra will be of value in identifying these compounds in the quantitative FAB mass spectrome tric protein kinase assay.