Hemoproteins Catalase, Hemoglobin, Myoglobin

In the editorial preface to the first volume of Advances in Catalysis the decision was made known not to publish reviews of specialized topics in biocatalysis but from time to time to bring reports in which the relationship and parallelism between this special field and normal catalysis are discussed. This is the first of these reports. Its purpose is to examine the reactions of four hemoproteins, hemoglobin, myoglobin, peroxidase, and catalase, which all contain the same coordination compound of iron—ferrous or ferric protoporphyrin attached to different protein molecules, with oxygen, hydrogen peroxide, and in a few cases additional reducing substances. Some of these reactions are specific ... 

Under certain pathological conditions, heme occurs free in tissues and it also occurs in normal tissues as the prosthetic group of a number of hemoproteins, such as hemoglobin, myoglobins, peroxidases, catalases and cytochrome c. It is that part of hemoglobin that giyes it its color. 

For practical purposes in immunohistochemistry, endogenous peroxidase activity can be defined as any activity that results in the decomposition of H202. Such activity is a common property of all hemoproteins such as hemoglobin (red cells), myoglobin (muscle cells), cytochrome (granulocytes, monocytes) and catalases (liver and kidney). Peroxidase activity may also be encountered in tissue areas adjacent to vascularized areas due to the diffusion of blood prior to fixation. 

The heme is then inserted into a protein to become a hemoprotein. In the case of non-covalently bound hemes (i.e. in hemoglobin and myoglobin, cytochromes h and P450, catalase, and peroxidases), the association between heme and apoprotein is spontaneous and does not require a catalyst. In contrast, the covalently bound hemes (e.g. cytochrome c) require... 

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