Ferriprotoporphyrin chloride

It might at first be thought that a study of the isolated porphyrins would be instructive, but in fact it transpires that their properties are somewhat different from those of the proteins. Accepted nomenclature is to use haeme for ferroprotoporphyrin, haemin to refer to ferriprotoporphyrin chloride, and haematin for ferriprotoporphyrin hydroxide. 

Keywords thiol, ferriprotoporphyrin(IX) chloride, peroxidase, oxidative coupling, disulfide... 

In addition to plant and animal sources, peroxidases are also found in mould, bacteria and microorganisms. A peroxidase from the mould Caldariomyces fumago, chloroperoxidase, has been isolated and characterised. Like the plant peroxidases it has ferriprotoporphyrin IX as the prosthetic group. In many of its chemical and physical properties chloroperoxidase is similar to horseradish peroxidase, but it has the unique ability amongst peroxidases to catalyse the oxidation of chloride ion (Hager et al., 1966 Morris and Hager, 1966). 

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