上海充通大学 SHANGHAI JIAO TONG UNIVERSITY 1.Proteins Are Built from a Repertoire of 20 Amino Acids Distinctive R goroup:sides,shape,charge, hydrogenbonding capacity,hydrophobic character.... H+ +H3N COOH +H3N H2N coO H+ H+ 兼性离子 Zwitterionic Both groups form deprotonated Both groups protonated 0 2 4 6 8 10 12 14 PH lonization state as a function of pH.1.Proteins Are Built from a Repertoire of 20 Amino Acids Ionization state as a function of pH. Distinctive R goroup: sides, shape, charge, hydrogenbonding capacity, hydrophobic character…. 兼性离子