Catalase crystalline

Assay of photoprotein. The activity of the photoprotein was measured in 1ml of 20 mM Tris-HCl buffer, pH 8.0, containing 0.6 M NaCl at room temperature. The intensity and total amount of light emitted were recorded. The luminescence intensity is markedly intensified by adding 5 il of catalase solution (crystalline bovine liver catalase 1.5 mg/ml) and 10 pi of 3% H2O2. 

Miller, J.M., Dunn, B., Valentine, J.S. and Zink, J.I. (1996) Synthesis conditions for encapsulating cytochrome c and catalase in Si02 sol-gel materials. Journal of Non-Crystalline Solids, 202, 279-289. 

M.J. Stansell and H.F. Deutsch, Preparation of crystalline erythrocuprein and catalase from human... 

The isolation of crystalline catalase-peroxidase has been an elusive goal that so far has not been achieved. The fact that there is no accurate... 

Using crystalline cytochrome-c peroxidase [38] and catalase [39], it is shown that intermediates are formed according to the general mechanism of acidic-basic catalysis ... 

Peroxisomes or microbodies are spherical organelles that are 0.3-1.5 pm in diameter. Each peroxisome is enveloped by a single external membrane, and its interior is full of proteins, frequently in crystalline form. Peroxisomes are characterized by the presence of various oxidative enzymes, which have variable functions dependent upon the origin of the peroxisome. These enzymes generate and utilize hydrogen peroxide (H2O2), hence the name peroxisome. This compound is very toxic for cells and is decomposed by the enzyme catalase to water and oxygen. 

Deutsch HF (1952) The properties of various crystalline horse erythrocyte catalase preparations. Acta Chem Scand 6 1516—1521... 

Willstatter and his collaborators challenged Sumner s claim that urease was a pure protein. After 1926 Sumner and collaborators provided further evidence that urease was indeed a protein molecule and that Willstatter s objections were based on incorrect experimentation. In 1930 Northrop had shown that pepsin was a protein, and in 1937 Sumner isolated catalase in pure crystalline condition. Sumner s initially controversial claims were thus fully vindicated. 

L-amino acid oxidases and a crystalline mass of urate oxidase, as well as enough catalase to decompose the hydrogen peroxide generated by these oxidases. 

Application of the negative staining-carbon film procedure to the much smaller human erythrocyte catalase (relative molecular mass 256 kDa) has resulted in the formation of several different para-crystalline and truly crystalline 2D forms, an occurrence also encountered with the E. colt chaperone GroEL. One of the catalase 2D crystal forms is... 

Major application advantages of preformed peroxy acids are their immediate availability in the bleach process and their stability in the presence of the enzyme catalase. Derived from aliphatic or aromatic carboxylic acids, the lower members of this class are liquid at room temperature, whereas higher homologues are stabilized in crystalline form by dimer formation. Aliphatic monoperoxy-carboxylic acids provide optimum bleaching at chain lengths of C6-C9, whereas a, (o-diperoxycar-boxylic acids perform best at chain lengths of C10-C14 [8]. 

The availability of several hydroperoxidases in the crystalline state and the knowledge of the nature of the prosthetic group in two peroxidases and the blood catalases (protohemin IX), as well as the possibUity of studying the reactions of these enzymes by spectroscopic and magnetic methods, have carried the study of the hydroperoxidases far ahead of that of other enzymes. 

Herbert and Pinsent (161) have isolated crystalline catalase from Micrococcus lysodeikticus. The washed organisms were first lysed with crystalline lysozyme. The activity (Kat. F.) of crystalline bacterial catalase is 90,000 units. Its molecular weight as estimated from its hemin content lies between 226,000 and 248,000. The enzyme composes about 2% of the dry weight of the cells. 

Catalase.— A ubiquitous and important enzyme found in all aerobic tissues. It catalyses the decomposition of hydrogen peroxide into water and inactive, molecular oxygen, thus protecting the tissues from the effects of hydrogen peroxide produced during aerobic oxidations. Catalase has recently been isolated as a crystalline hsemo-protein from beef liver by Surdner (1937). 

D. Catalase is almost universal in plant and animal tissues, a particularly rich source being horse liver, from which the enzyme has been obtained in crystalline form. Catalase converts hydrogen peroxide to water and free o gen. Hydrogen peroxide is a toxic compound, and may arise in various biological oxidations. By means of a peroxidase system it may be employed to effect subsequent oxidations, or by means of catalase it may be removed rapidly. 

Catalase is an enzyme which breaks HsOs into H O and O. Its active group is protohemin. It has an unusually high activity (as measured by the turnover number). The molecular weight of the crystalline protein comes to 240,000. There are four heme groups in each molecule. 

However, there are three different tests for resolution, and there is no agreement as to which method is best. Further, very few materials are suitable for resolution tests. In most problems, there is no need for resolutions of better than 5 A, and with most samples it would be difficult to prove resolution of below 10 A. Resolutions of 2-3 A were recently achieved for intercalation complexes of superconducting Ta 2, allowing direct observation of the crystalline lattice and its imperfections. Computer enhancement of high-resolution electron micrographs of stained and unstained catalase crystals show amazing... 

However, o-benzoquinone was ruled out as a dissociable intermediate in this process (Hayaishi et al., 1957b). Furthermore, attempts to demonstrate participation of H2O2 as a free intermediate have been uniformly unsuccessful. For example, ethyl alcohol (1 M) inhibits the reaction by about 10%, but further addition of a high concentration of catalase (approximately 0.9 mg. of crystalline catalase per milliliter, corresponding to 660 units) did not increase the degree of inhibition. Likewise, peroxidase 1200 units) and p-aminobenzoic acid (10 Af), in the standard manometric assay, failed to show any evidence for free H2O2 formation. 

The factor in glucose dehydrogenase preparations which can stimulate tyrosine formation can be replaced by crystalline catalase when tetrahydropteridines are used while catalase cannot replace glucose dehydrogenase with the cofactor. It is possible that the glucose dehydrogenase fractions contain another factor, besides catalase, which is required for the activity of the cofactor. This additional factor may also be involved in the conversion of the cofactor to an active form. 

L-Lysine is converted by an enzyme from a strain of Pseudomonas into y-aminovalerianic acid, NH3, and COg. The rate of incorporation of in dry matter is fairly important. These results point to the frequent occurrence of reactions such as (91) and many others similar and unknown. In the L-lysine oxidase experiments oxygen consumption cannot be affected by crystalline catalase. Methylene blue, triphenyltetrazolium chloride, and 2,6-dichlorophenolindolephenol cannot replace oxygen. 

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