Figure 6

High resolution MALDI-FTICR MS resolves neuropeptides PDNFMRFamide and Drostatin-3 (Ast-A3), convoluted in MALDI-TOF mass spectra. Through the use of MALDI-FTICR MS, we were able to resolve m/z 925.481 from the MALDI-TOF MS (top) as being the convolution of two neuropeptides. PDNFMRFamide, identified by MALDI-TOF/TOF MS/MS fragmentation, was observed in MALDI-FTICR MS (bottom) as 925.43564 (theoretical monoisotopic [M + H]⁺ = 925.43594). A second peak at m/z 925.49004 was tentatively assigned to correspond to Drostatin-3 (Ast-A3, calculated [M + H]⁺ = 925.48994).