Hemoproteins

complex proteins containing the pigmented prosthetic group—hemes. Hemoproteins are classified as chromoproteins. In addition to the respiratory pigments—hemoglobin and myoglobin—hemoproteins include widely distributed respiratory enzymes—cytochromes— and oxidative enzymes of tissues—peroxidase, which catalyzes the oxidation of organic substances by hydrogen peroxide, catalase, and leghemoglobin (legoglobin), a pigment found in the root nodules of leguminous plants.