Labelling of penicillin-binding proteins from Escherichia coli with photoreactive derivatives of #betta#-lactam antibiotics

The authors have synthesized a number of photoreactive radiolabelled #betta#-lactams that react and form permanent covalent bonds with the penicillin-binding proteins (PBPs), since photoreactive ligand derivatives have been used to some extent for structural studies on membranes and other biological structures. Chemical and photochemical labelling of a receptor by its ligand are important techniques to elucidate the nature of the ligand-receptor interaction, and for identification and characterization of receptors. They have synthesized two #betta#-lactam derivatives each containing two different photoreactive moieties. One of them is an aryl azido compound, widely known as a photoreactive reagent for labelling studies, whereas the other one contains a nitroguaiacol derived group used in photochemical studies with other biological materials. (Auth.)