Another modification that reduces the overall charge of a protein, and thus influences proteoform We also see how the loss of uncharged amino acid residues influences proteoform migration when analysing the retention times of the (Ac)VP3 and (Ac)VP3 variants in serotypes AAV6 and AAV8. In both serotypes the (Ac)VP3 variants are detected earlier than their respective (Ac)VP3 proteoforms (Figure , Top and Centre). This is a product of the A204-M211 (or A205-M212 for AAV8) sequence present in (Ac)VP3 but not the (Ac)VP3 variant, not contributing to the overall charge of the (Ac)VP3