Ferrochelatase catalyzes the formation of Zn-protoporphyrin of dry-cured ham via the conversion reaction from heme in meat.

Ferrochelatase (FECH), the enzyme at the last step of the heme-biosynthetic pathway, is involved in the formation of Zn-protoporphyrin via an iron-removal reaction of heme. To improve the efficacy of the formation of Zn-protoporphyrin from heme, the use of recombinant FECHs from porcine, yeast, and bacteria was examined. Incubation of FECH with myoglobin in the presence of ascorbic acid and cysteine resulted in the efficient conversion of myoglobin-heme to Zn-protoporphyrin.

Porcine ferrochelatase: the relationship between iron-removal reaction and the conversion of heme to Zn-protoporphyrin.

At the terminal step of heme biosynthesis, ferrochelatase (FECH) catalyzes the insertion of Fe2+ into protoporphyrin to form heme. It is located on the inner membrane of the mitochondria of animals. The enzyme inserts divalent metal ions, including Fe2+, Co2+, and Zn2+, into porphyrins in vitro.

Dual mitochondrial localization and different roles of the reversible reaction of mammalian ferrochelatase.

Ferrochelatase catalyzes the insertion of ferrous ions into protoporphyrin IX to produce heme. Previously, it was found that this enzyme also participates in the reverse reaction of iron removal from heme. To clarify the role of the reverse reaction of ferrochelatase in cells, mouse liver mitochondria were fractionated to examine the localization of ferrochelatase, and it was found that the enzyme localizes not only to the inner membrane, but also to the outer membrane.

Heme synthase (ferrochelatase) catalyzes the removal of iron from heme and demetalation of metalloporphyrins.

The red pigments in meat products, including cooked cured ham, arise from the reaction of myoglobin with nitric oxide generated from exogenous nitrite. Since carcinogenic nitrosoamines may be generated by the treatment of meats with nitrite, the production of nitrite-free meat products is an attractive alternative. Raw dry-cured (Parma) hams are produced by the treatment of meats with salts other than nitrite.