Beef liver catalase, crystals

Mn Catalase. The majority of known catalases contain a heme prosthetic group to catalyze the disproportionation of hydrogen peroxide. These enzymes are long established (e.g., the beef liver catalase was crystallized in 1937 (13)) and are believed to protect respiring cells... 

FIGURE 1.10 Crystals of a variety of proteins. In (a) hexagonal prisms of beef liver catalase. In (b) crystals of oo acid glycoprotein, in (c) Fab fragments of a murine immunoglobulin, and in (d) rhombohedral crystals of the seed storage protein canavalin. 

FIGURE 1.11 Electron micrographs of negatively stained crystals of (a) pig pancreatic a amylase, and (b) beef liver catalase. The dark areas represent solvent filled areas in the crystal, which are replaced by dense heavy metal stain the light areas correspond to protein molecules where the stain is excluded. The underlying periodicity of the crystals is evident here, even after dehydration and staining. 

Most catalases consist of four subunits of 60,000 mol each and contain one ferri-protoporphyrin IX molecule per subunit. With few exceptions, catalases are found in all but anaerobic organisms. The crystal structure of beef liver catalase has been determined to 2.5 pm resolution ", and the primary sequence is also known. ... 

X-ray crystal structures have been determined for beef-liver catalase and for horseradish peroxidase in the resting, high-spin ferric state. In both, there is a single heme b group at the active site. In catalase, the axial ligands are a... 

Catalase. Crystallization of beef liver catalase and its molecular weight. Sunilaiity of various animal catalases. Total iron and heme iron in catalase. Amino acid content of horse liver catalase. 

Catalase (H202 H202 oxidoreductase EC 1.11.1.6) was one of the first enzymes to be isolated in a high state of purity, and its crystallization (29) from beef liver extracts ranked among the early triumphs of biochemistry. Extensive physicochemical studies which followed (30-41) led to an impressive elucidation of its properties, but as yet not to a definition of the apoprotein function in the enzyme catalysis. 

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