Acidic proteins

The category groups proteins that have a low isoelectric point (pI), and therefore tend to be negatively charged at physiological pH (7.4).

Quantitatively, proteins in this category have a charge q at physiological pH and a number of residues N such that

${\displaystyle \frac{q}{\sqrt{N}} < -0.25 }$

This criterion is met by roughly one-third of the proteins in Arabidopsis thaliana.