Mass Spectrometry of Putrescine, Spermidine, and Spermine Covalently Attached to Francisella tularensis Universal Stress Protein and Bovine Albumin

Figure 9

Scheme showing the addition of acrylamide to cysteine to form cysteine-propionamide with an added mass of 71 Da from acrylamide. The added mass from putrescine is also 71 Da. Acrylamide adducts on cysteine have been previously reported in proteins extracted from a polyacrylamide gel [12, 13].