Short Hydrogen Bonds and Proton Delocalization in Green Fluorescent Protein (GFP).

ABSTRACT: Short hydrogen bonds and specifically low-barrier hydrogen bonds (LBHBs) have been the focus of much attention and controversy for their possible role in enzymatic catalysis. The green fluorescent protein (GFP) mutant S65T, H148D has been found to form a very short hydrogen bond between Asp148 and the chromophore resulting in significant spectral perturbations. Leveraging the unique autocatalytically formed chromophore and its sensitivity to this interaction we explore the consequences of proton affinity matching across this putative LBHB. Through the use of noncanonical amino acids introduced through nonsense suppression or global incorporation, we systematically modify the acidity of the GFP chromophore with halogen substituents. X-ray crystal structures indicated that the length of the

SUBMITTER: Oltrogge LM 

PROVIDER: S-EPMC4827562 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature