An AM1 analysis of hydrogen bonds in the TOPA quinone cofactor of amine oxidases

Abstract

The 1:1 interaction of 2,5-dihydroxy- p-quinone (DH pQ) with bases such as pyridine, ammonia, water, and methanol was studied by means of the AM1 molecular orbital method. Optimized geometries demonstrated the orientating power of the DH pQ functional group, consisting of one CO group and the adjacent OH group on the H-bonded base. The implications relating to trihydroxyphenylalanine (TOPA) quinone, the cofactor of amine oxidases containing the same functional group, are discussed.