A blue-green absorbing cross-linker for rapid photoswitching of peptide helix content.
Azobenzene derivatives can be used to reversibly photoregulate secondary structure when introduced as intramolecular bridges in peptides and proteins. Here we report the design, synthesis, and characterization of a disubstituted N,N-dialkyl azobenzene derivative that absorbs near 480 nm in aqueous solution and relaxes with a half-life of approximately 50 ms at room temperature. The wavelength of maximum absorbance and the rate of thermal relaxation are solvent-dependent. An increase in the percentage of organic solvent leads, in general, to a blue shift in the absorbance maximum and a slowing of the relaxation rate. In accordance with the design, the thermal relaxation of the azobenzene cross-linker from cis to trans causes an increase in the helix content of one peptide where the linker is attached via cysteine residues spaced at i, i + 11 positions and a decrease in helix content of another peptide with cysteine residues spaced at i, i + 7. This cross-linker design thus expands the possibilities for fast photocontrol of peptide and protein structure.
Chi
Lei
L
Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, ON M5S 3H6, Canada.
Sadovski
Oleg
O
Woolley
G Andrew
GA
D003116:Color; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D010777:Photochemistry; D017433:Protein Structure, Secondary; D012997:Solvents; D013057:Spectrum Analysis; D013997:Time Factors
D003432:Cross-Linking Reagents; D010455:Peptides; D012997:Solvents