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Publication year - 2019
Publication title -
biopolymers
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.23270
Subject(s) - salt bridge , chemistry , protonation , cover (algebra) , salt (chemistry) , carboxylate , cage , construct (python library) , stereochemistry , crystallography , combinatorics , computer science , biochemistry , organic chemistry , mathematics , programming language , mechanical engineering , ion , mutant , engineering , gene
Graham et al . present a structural comparison between a standard Trp‐Cage miniprotein shown at pH 7, and an analog optimized for stability under acidic conditions shown at pH 2.5. The folded state of Trp‐Cage TC16b (green) involves several pH‐sensitive interactions which are disrupted upon carboxylate protonation, making it most stable at pH 7. The truncated (R16Nva)‐trTC16b (purple) eliminates several of these interactions, most notably an Asp/Arg salt bridge. The result is a Trp‐Cage construct more stable at pH 2.5 than at pH 7. The overall Trp‐Cage structure is maintained, however, even in the absence of the salt bridge. (DOI: 10.1002/bip.23260 )