Table II. Substrate specificities of GOX1, GOX2, and GOX3

Enzyme activities were determined using heterologously expressed and purified enzymes and standard assay conditions using a range of substrates at a concentration of 5 mm (glycolate to l-lactate and leucic acid to isoleucic acid) and 0.5 mm (2-hydroxyhexanoic acid to 2-hydroxyhexadecanoic acid, all dissolved in ethanol), and product accumulation using phenylhydrazine (oxygen as electron acceptor) was monitored photometrically. Shown are mean values of the activities relative to the best substrate of at least two independent experiments. —, No activity was detected.

SampleRelative Oxidase Activity
GOX1GOX2GOX3
%
Glycolate100100100
l-Lactate454876
2-Hydroxyhexanoic acid0.29.4
2-Hydroxyoctanoic acid2.414.3
2-Hydroxydodecanoic acid1.88.8
2-Hydroxyhexadecanoic acid0.4
Leucic acid16.1
Valic acid0.1
Isoleucic acid0.1