aa2chargePos = {'K': 10.5, 'R':12.4, 'H':6} aa2chargeNeg = {'D': 3.86, 'E': 4.25, 'C': 8.33, 'Y': 10} aaNterm = 9.69 aaCterm = 2.34

In simple Python code please

This method calculates the net charge on the protein at a specific pH (specified as a parameter of this method). The method is used by the pl method marked it with the single _ notation to advise future users of the class that this is not part of the defined interface and it just might change. If we have the composition of our protein, we can then calculate the net charge at a particular pH, using the pKa of each charged Amino acid and the Nterminus and Cterminus