Crystalline Catalase

Sumner, James B.; Dounce, Alexander L.

doi:10.1126/science.85.2206.366

Cited by 93 publications

(64 citation statements)

References 2 publications

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“…Dounce (1937Dounce ( , 1939 used to purify liver catalase, denatures bacterial catalase very rapidly atroom temperature and still rapidly at 00; we were able to obtain fairly pure preparations by Sumner's method working at 00, but only in very low yields. or the prosthetic group, and the nature of the latter was investigated in some detail.…”

Section: Methodsmentioning

confidence: 85%

Crystalline Bacterial Catalase

Herbert

Pinsent

1947

Nature

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spectroscope the narrow width of the absorption band in the red led to an overestimate of its intensity. Others have also been misled by the narrowness of the first absorption band; thus Grinstein, Schwartz & Watson (1945) describe the relative intensities of the absorption bands of coproporphyrin I as IV, III, I and II in decreasing order.The eluate containing the second porphyrin zone was evaporated to dryness, and after recrystallization from chloroform and methanol gave 7-1 mg. of the typical hairlike crystals of uroporphyrin I octamethyl ester (m.p. 288°). In chloroform, this ester showed absorption bands at 625-7, 576-7, 536-5 and 503-6 mi., intensity IV>III>II>I (Hartridge reversion spectroscope). The third porphyrin zone has not yet been identified. DISCUSSIONThe isolation of coproporphyrin III ester in relatively enormous quantities in the large-scale production of purified diphtheria toxoid provides an abundant and hitherto unexplored source of coproporphyrin III, which wiU be of the greatest value in the investigation of the metabolic relationships of this material in the intact animal. The production of small quantities of uroporphyrin I provides yet another example of the so-called dualism of the porphyrins, attention to which was first drawn by Fischer (1937). In the light of present knowledge it is not possible to speculate on the significance of this dualism to the economy of the organism. The implications suggested by Pappenheimer (1947) regarding the relationship of the production of porphyrin to toxin formation will be the subject of a separate paper to be published elsewhere. SUMMARYCoproporphyrin III tetramethyl ester in large yield and uroporphyrin I octamethyl ester in very small yield have been prepared from toxic culture filtrates of Corynebacterium diphtheriae.

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Section: Methodsmentioning

confidence: 85%

Crystalline Bacterial Catalase

Herbert

Pinsent

1947

Nature

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“…In general, SOD catalyzes ⋅O 2 − into H 2 O 2 and CAT catalyzes the decomposition of H 2 O 2 to H 2 O and O 2 . 35 GPx is an enzyme family with peroxidase activity, and its major biological role is to protect the organism from oxidative damage, reduce lipid hydroperoxides to their corresponding alcohols and reduce H 2 O 2 to H 2 O. In our study, the activities of SOD, CAT and GPx of the liver and kidneys of mice exposed to CdTe QDs were significantly increased in Figure 6 Oxidative stress markers of the liver (A-E) and kidneys (F-J) in mice exposed to 1.5 µmol/kg cdTe QDs for periods of up to 28 days.…”

Section: Discussionmentioning

confidence: 99%

Dose and time effect of CdTe quantum dots on antioxidant capacities of the liver and kidneys in mice

Wang

Sun

Meng

et al. 2017

IJN

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Although quantum dot (QD)-induced toxicity occurs due to free radicals, generation of oxidative stress mediated by reactive oxygen species (ROS) formation is considered an important mechanism. However, free radical mechanisms are essentially difficult to elucidate at the molecular level because most biologically relevant free radicals are highly reactive and short-lived, making them difficult to directly detect, especially in vivo. Antioxidants play an important role in preventing or, in most cases, limiting the damage caused by ROS. Healthy people and animals possess many endogenous antioxidative substances that scavenge free radicals in vivo to maintain the redox balance and genome integrity. The antioxidant capacity of an organism is highly important but seldom studied. In this study, the dose and time effects of CdTe QDs on the antioxidant capacities of the liver and kidneys were investigated in mice using the electron paramagnetic resonance (EPR) spin-trapping technique. We found that the liver and kidneys of healthy mice contain specific antioxidant capacities that scavenge ·OH and ·O 2 − . Furthermore, oxidative stress markers (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], glutathione [GSH] and malondialdehyde [MDA]) were examined. In dose course studies, the free radical scavenging efficiencies of the liver and kidneys were found to gradually decrease with increasing concentration of CdTe QD exposure. The activities and levels of SOD, CAT, GPx and MDA were observed to increase in treated groups, whereas those of GSH were reduced. The time course studies revealed that the QD-induced antioxidant efficiency reduction was time dependent with GSH decrease and could recover after a period of time. These experimental results offer new information on QD toxicity in vivo. Specifically, CdTe QDs can deplete GSH to reduce the elimination ability of the liver and kidneys for ·OH and ·O 2 − , thus inducing oxidative damage to tissues.

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“…The properties of the enzyme have been thoroughly reviewed (Deisseroth & Dounce, 1970;Murthy et al, 1981;Schonbaum & Chance, 1976). Beef liver catalase is easily crystallized in a variety of forms (Schnuchel, 1954;Rossmann & Labaw, 1967; and was, in fact, one of the ®rst enzymes crystallized (Sumner & Dounce, 1937).…”

Section: Introductionmentioning

confidence: 99%

Structure of orthorhombic crystals of beef liver catalase

Day

Malkin

et al. 1999

Acta Crystallogr D Biol Cryst

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The growth mechanisms and physical properties of the orthorhombic crystal form of beef liver catalase were investigated using in situ atomic force microscopy (AFM). It was observed that the crystals grow in the 〈001〉 direction by an unusual progression of sequential two-dimensional nuclei of half unit-cell layers corresponding to the `bottoms' and `tops' of unit cells. These were easily discriminated by their alternating asymmetric shapes and their strong growth-rate anisotropy. This pattern has not previously been observed with other macromolecular crystals. Orthorhombic beef liver catalase crystals exhibit an extremely high defect density and incorporate great numbers of misoriented microcrystals, revealed intact by etching experiments, which may explain their marginal diffraction properties. To facilitate interpretation of AFM results in terms of intermolecular interactions, the structure of the orthorhombic crystals, having an entire tetramer of the enzyme as the asymmetric unit, was solved by molecular replacement using a model derived from a trigonal crystal form. It was subsequently refined by conventional techniques. Although the packing of molecules in the two unit cells was substantially different, with very few exceptions no significant differences in the molecular structures were observed. In addition, no statistically significant deviation from ideal 222 molecular symmetry appeared within the tetramer. The packing of molecules in the crystal revealed by X-ray analysis explained in a satisfying way the process of crystal growth revealed by AFM.

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Crystalline Catalase

Cited by 93 publications

References 2 publications

Crystalline Bacterial Catalase

Crystalline Bacterial Catalase

Dose and time effect of CdTe quantum dots on antioxidant capacities of the liver and kidneys in mice

Structure of orthorhombic crystals of beef liver catalase

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