Excitation energy transfer study of the spatial relationship between the carbonyl and metal cofactors in pig plasma amine oxidase

Mechanisms Whereby Mononuclear Copper Proteins Functionalize Organic Substrates

“…Through a combination of EXAFS, pulsed EPR, and NMR solvent relaxation studies, the copper site in resting enzyme was concluded to be in the cupric state and to be of square-pyramidal geometry, containing three equatorial histidines, an equatorial water, and an axial water as ligands. − , Distance mapping experiments using NMR, EPR, and fluorescent energy transfer provided an estimate of the relationship between copper and the reactive carbonyl of the active site organic cofactor. Although the original data were interpreted in the context of active site PQQ as cofactor, subsequent reanalysis of the data in the context of TPQ implicated a distance of ∼3.0Å between the C-2 oxygen of the quinocofactor and copper. , …”