Sequence-Controlled Secondary Structures and Stimuli Responsiveness of Bioinspired Polyampholytes

Biomacromolecules. 2022 Sep 12;23(9):3798-3809. doi: 10.1021/acs.biomac.2c00666. Epub 2022 Aug 15.

Abstract

A comprehensive study focusing on the influence of the sequence charge pattern on the secondary structure preferences of annealed polyampholytes and their responsiveness to external stimuli is presented. Two sequences are designed 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. The study reveals that the sequence charge pattern has a significant influence on the secondary structure preferences of polyampholytes at physiological pH. Furthermore, it shows that external stimuli such as pH, ionic strength, and solvent dielectric constant can be used to modulate the secondary structure of the two studied sequences. The observed secondary structure transformations for the two sequences are also substantially different from those determined for uniformly charged homo-polypeptides under matching conditions.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Peptides* / chemistry
  • Protein Structure, Secondary
  • Solvents

Substances

  • Peptides
  • Solvents