Keyword - Isomerase
Enzyme that catalyzes the 1,1-, 1,2- or 1,3-hydrogen shift. The 1,1-hydrogen shift is an inversion at an asymmetric carbon center (racemases, epimerases). The 1,2-hydrogen shift involved a hydrogen transfer between two adjacent carbon atoms, one undergoing oxidation, the other reduction (aldose-ketose isomerases). The 1,3-hydrogen shifts are allylic or azaallylic (when nitrogen is one of the three atoms) isomerizations.