Figure 4.
Neuropeptides from single AVK neurons in native and acetylated forms. (a) Mass spectrum from an individual AVK with no chemical modifications. (b) Expansion of (a) from m/z 1000–1200. (c) Spectrum from an individual AVK treated with acetic anhydride, which acetylates free amines (N-terminus, K) and to a lesser extent Y, and adds 42 mass units. (d) Expansion of (c) from m/z 1000–1200. X axis: m/z is mass-to-charge ratio. Y axis is intensity of MS signal in arbitrary units, a.u. Asterisk (*) indicates extended peptide due to incomplete cleavage.