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Genetic Incorporation of a Reactive Isothiocyanate Group into Proteins
Author(s) -
Xuan Weimin,
Li Jack,
Luo Xiaozhou,
Schultz Peter G.
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201604891
Subject(s) - thiourea , chemistry , isothiocyanate , intramolecular force , salt bridge , amine gas treating , residue (chemistry) , myoglobin , amino acid , thermal stability , combinatorial chemistry , biochemistry , stereochemistry , organic chemistry , mutant , gene
Methods for the site‐specific modification of proteins are useful for introducing biological probes into proteins and engineering proteins with novel activities. Herein, we genetically encode a novel noncanonical amino acid (ncAA) that contains an aryl isothiocyanate group which can form stable thiourea crosslinks with amines under mild conditions. We show that this ncAA (pNCSF) allows the selective conjugation of proteins to amine‐containing molecular probes through formation of a thiourea bridge. pNCSF was also used to replace a native salt bridge in myoglobin with an intramolecular crosslink to a proximal Lys residue, leading to increased thermal stability. Finally, we show that pNCSF can form stable intermolecular crosslinks between two interacting proteins.