And we also have three amino acids coming from the beta two, also the HistoGene two, the Lysine 82 and the histadine 143. And each one of these amino acids contain side chain groups, which contain a positive charge. And so together, these six amino acids create a relatively large positive charge at the center of that hemoglobin. And this molecule, the two three BPG, contains 12345 negative charges. And that's exactly why this molecule is able to bind at the center pocket, because there is a strong electric attraction between these negative charges and the positive charges found along the following six amino acids. So this is the two three BPG molecule, and it binds the electrostatic forces with these six amino acids.