I am analyzing ESI/MS and MALDI/TOF MS spectra of a small protein subjected to CNBr digestion in 70% formic acid at room temp overnight and then digested with Asp-N proteinase. There appear to be fragments compatible with cleavages at Asp residues, as expected, but also some atypical cleavages at Glu residues (which I have seen before in other similar instances), as well at Gln residues, which may be explained by admitting that Gln residues were deamidated (also considering the associated increment of 0.984 mass units). Don't seem to notice deamidation of the two Asn residues present in the sequence, but these were glycosylated. Many thanks to anybody who may provide an answer.