For example here http://www1.lsbu.ac.uk/water/enztech/nomenc.html
they have
D-xylose ketol-isomerase
g-L-glutamyl-L-cysteine:glycine ligase
b-D-glucose:oxygen 1-oxidoreductase
L-histidine ammonia-lyase
so once they include the colon, once they omit it. Or is it case-specific?