... deamidated before any other resi-due. In a similar fashion, the samples with 1.8, 3.7 and 4.4 Da increases show that Asn71 and Asn94 arenearly equally reactive as the next sites, followed by Asn34 ... mass accuracy [6,18,23,34].Furthermore, these fragment mass values originate from the same molecular ions, so they must all becharacteristic of that protein s sequence and molecularmass value. ... modifications of the enzyme, the effect of the inhibitor on the molecular mass value of HAD was measured; instead of an adduct increase, orno change, the value had unexpectedly decreased from 22...