Principles of Biochemistry (2+1)

8.1.2.1 Cofactor

The cofactor may be either inorganic, such as Fe²⁺, Mn²⁺ or Zn²⁺ ions. Some enzymes require both a coenzyme and one or more ions for their activity. In some enzymes the coenzyme or metal ion is only loosely and transiently bound to the protein, but in others it is called a prosthetic group.

Some Enzymes containing Cofactors

Cofactors	Associated enzymes
Fe 2+ or Fe 3+	Cytochrome oxidase Catalase Peroxidase
Cu2+	Cytochrome oxidase
Zn2+	DNA polymerase Carbonic anhydrase Alcohol dehydrogenase
Mg2+	Hexokinase  Glucose 6- Phosphatase
Mn2+	Arginase Pyruvate kinase (also requires Mg2+)
K+	Urease
Ni2+	Nitrate reducatase
Se 2+	Glutathione peroxidase