Incorporation of N ‐Glycine Residues Into Collagen to Form Salt Bridges

ABSTRACT Collagen, the principal structural protein in mammals, adopts a right‐handed triple helix composed of three left‐handed polyproline‐II helical polypeptide chains featuring repeating Gly‐Xaa‐Yaa tripeptide motifs. Positions Xaa and Yaa frequently contain charged amino acids, which can form salt bridges to stabilize the collagen triple‐helical conformation and fibril formation. Over the past decades, researchers have exploited the charged amino acids to engineer salt bridges for constructing stable collagen‐based biomaterials. However, the use of amino acid analogues to form salt bridges remains largely unexplored. Herein, we report for the first time the incorporation of charged N ‐gly residues into host‐guest collagen mimetic peptides (CMPs) to establish salt bridges. Among these, the EGNap CMP exhibited the highest T m value of 48.2°C, marginally lower than that of the OGP sequence. Molecular modeling indicates that the N ‐gly can form salt bridges with the amino acid, but the distance of these salt bridges is greater than that of KGD. These findings establish a foundational strategy for leveraging N ‐gly‐mediated electrostatic interactions in collagen engineering.