Draw a schematic of the chemical structure of the Asn-Ser-Met-Glu tetrapeptide, with the corect ionization at neutral pH. Also, give an estimate the pl of this tetrapeptide (you may assume the pKa of any acidic R group is 4, the pKa of any basic R group is 11.5, and the pKa of the alpha-COOH is 2, and the alpha-NH3 is 9.5).