Influence of Sequence Charge Pattern on Secondary Structures of Bioinspired Polyampholytes

A systematic investigation of the influence of sequence charge pattern on the secondary structure preferences of peptide-based polyampholytes and their responsiveness to external stimuli will be presented. The polyampholyte sequences utilized in this study are composed entirely of ionizable amino acids (charge fraction, f=1), and an equal number of positive and negative charges (f₊=f_-=0.5) with distinct charge patterns consisting of lysine and glutamic acid monomers. Our work reveals that the sequence charge pattern has a pronounced influence on the secondary structure preferences of polyampholytes at physiological pH. Furthermore, it demonstrates that external stimuli such as pH and ionic strength can be used to modulate the secondary structure of the examined polyampholytes. The observed structural transformations are different from those determined for uniformly charged homo-polypeptides under matching conditions.