Industrial Biotransformations

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2 The Enzyme Classification
EC 1.4 Acting on the CH–NH 2 group of donors
H
R 1
NH 2
R 2
cofactor + NH3 R 1
R 2
NH
R 1
R 2
O
H2O R 1,2 = hydrogen, organic residue
In most cases the imine formed is hydrolyzed to give an oxo-group and ammonia (deaminating).
The division into sub-subclasses depends on the cofactor.
EC 1.5 Acting on the CH–NH group of donors
H
R 1
NHR 3
R 2
cofactor + R 3 NH2 R 1
R 2
NR 3
R 1
R 2
O
H2O R 1,2 = hydrogen, organic residue
R 3 = organic residue
In some cases the primary product of the enzymatic reaction can be hydrolyzed. The
further classification is based on the cofactors.
EC 1.6 Acting on NAD(P)H
NAD(P) H NAD(P) +
+ A + A H
A = acceptor
In general, enzymes that use NAD(P)H as the reducing agent are classified according to
the substrate of the reverse reaction. Only enzymes that require some other redox carrier
as acceptors to oxidize NAD(P)H are classified in this subclass. Further division depends
on the redox carrier used.
EC 1.7 Acting on other nitrogen compounds as donors
N redR 3
cofactor
N oxR 3
R = hydrogen, organic residue, oxygen
The enzymes that catalyze the oxidation of ammonia to nitrite and the oxidation of nitrite
to nitrate belong to this subclass. The subdivision is based on the cofactor.