Biological Role of Galactose Oxidase

At present, galactose oxidase has only been found in specific classes of fungi. The completion of sequencing the genomes of Arabidopsis, of nematodes and in the relatively near future of humans will allow sequence data bases to be searched for a wider distribution of galactose oxidase in Nature. 

Amine oxidases catalyse the oxidative deamination of mono-, di-and polyamines according to the following general reactions which involve attack at either primary amine sites (1) or secondary amine sites 

There is a broad division of amine oxidases into two classes, flavin-containing and copper-containing. The flavin class (EC 1.4.3.4) is commonly associated with the peroxisomes and mitochondria in cells and can attack substrates at both primary and secondary amine sites, (1) and (2) above. 

FIGURE 10. Structure of (a) trihydroxyphenylalanine quinone (TPQ) (b) TPQ semi-quinone (c) aminoquinol form of TPQ present in the substrate-reduced form of amine oxidases. 

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