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Bis‐Azobenzene Crosslinkers for Photocontrol of Peptide Structure
Author(s) -
Samanta Subhas,
Woolley G. Andrew
Publication year - 2011
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.201100204
Subject(s) - photoswitch , azobenzene , photoisomerization , chemistry , isomerization , helix (gastropod) , peptide , photochromism , biomolecule , spiropyran , stereochemistry , photochemistry , molecule , organic chemistry , catalysis , biochemistry , ecology , snail , biology
Crosslinkers that undergo large changes in length upon photoisomerization can produce large conformational changes, and thereby functional changes, in biomolecules. We have designed and synthesized extended and rigid bis‐azobenzene crosslinkers: 4,4′‐bis(4‐(2‐chloroacetamido)phenyl)diazenylbiphenyl (BPDB) and the water‐soluble sulfonated analogue 4,4′‐bis(4‐(2‐chloroacetamido)phenyl)diazenylbiphenyl‐2,2′‐disulfonate (BPDBS). These photoswitches can produce end‐to‐end distance changes of a minimum of ≈5 Å and a maximum of ≈23 Å upon trans / cis isomerization. They have high absorption coefficients (45–60 000 M −1 cm −1 ) and can produce up to ≈80 % cis isomers under favorable conditions. The photoswitching behavior of BPDBS‐crosslinked peptides was found to be highly dependent on the crosslinker attachment site. Upon UV irradiation (365 nm), significant decreases in α‐helix content were observed for peptides that were crosslinked with BPDBS through Cys residues at i , i +19, and i , i +21 positions. In contrast, large increases in α‐helix content were exhibited by i , i +11 crosslinked peptides. BPDBS thus constitutes a particularly bright and effective photoswitch for biomolecule photocontrol.