N-terminal L-aspartyl-L-aspartyl-L-aspartyl(2-) residue
n-terminal l-aspartyl-l-aspartyl-l-aspartyl(2-) residue
N-terminal <small>L</small>-Asp-<small>L</small>-Asp-<small>L</small>-Asp residue; major microspecies at pH 7.3