Phenol oxidase occurrence

Fetterer, R.H. and Hill, D.E. (1993) The occurrence of phenol oxidase activity in female Trichuris suis. Journal of Parasitology 79, 155—159. 

Whether the occurrence of an enzyme in a particulate fraction really represents its in vivo location can be substantiated by the following properties (a) close binding to membrane lipids, cf. cyclopenase (D 8.4.2), which is a lipoprotein of the plasma membrane (b) cooperation with other enzymes, cf. the catalytic facilitation in the biosynthesis of cyanogenic glycosides, cinnamic and benzoic acids (A 3.1) and (c) in situ examination by cytochemical methods, cf. the localization of phenol oxidases (C 2.3.1), peroxidases (C 2.4) and thioglucosidases (D 9.4). 

The widespread occurrence of the polyphenolase in plants has, however, Ipng made it seem likely that these oxidases play an important part in respiration. Onslow s studies (1920-1924) emphasized the wide distribution in plant tissues of o-dihydric phenols such as caffeic and pro-tocatechuic acids, and focused attention on the possibility that the enzymatic oxidation of such substances was an important part of the plant respiratory process. Since then many investigators have attempted to show that polyphenolase acts as a terminal oxidase. 

---