Cadmium Chelation by Bacterial Teichoic Acid from Solid-State Nuclear Magnetic Resonance Spectroscopy

Art effective means of studying biological metal chemistry is through the use of cadmium NMR to probe the interaction between biomolecules, Such as proteins and peptides, with divalent metals, such as zinc, copper, magnesium, or calcium Gram-positive bacteria, Such as S. aureus and B subtilis, have peptidoglycan cell walls that contain teichoic acids, it poly(phosphodiester) biopolymer used for, among other things, metal chelation Previous solid-state NMR and XAFS studies have shown that the cadmium ion binds in a bidentate manner to the phosphoryl centers of the dried teichoic acid backbone at physiological pH However, current studies indicate that, when hydrated and at file low concentrations typically found in nature, the cadmium toils and phosphoryl sites interact through an extended solvent-separated ion pairing. These data reveal two unequal P-Cd interactions at distances of 4 2 and 4 9 angstrom set approximately 180 degrees from each other in a linear arrangement.