Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two isozymes of catalase (EC 1.11.1.6), one with typically low peroxidatic activity (CAT-1) and the other with enhanced-peroxidatic activity (EP-CAT or CAT-3) have been purified to electrophoretic homogeneity from tobacco (Nicotiana sylvestris) seedlings and antibodies prepared against each. The isozyme proteins showed no immunological cross-reactivity. The subunit Mr was 55,300 +/- 750 for CAT-1 and 53,300 +/- 850 for CAT-3 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the catalatic reaction, the apparent Km values for CAT-1 and CAT-3 were 0.057 and 0.054 M, respectively, and the kcat values were 4.8 x 10(7) and 3.0 x 10(6) min-1, respectively. In the peroxidatic reaction, both have similar apparent Km's for H2O2. The apparent Km values for CAT-3 for the series methyl, ethyl, propyl, butyl, and allyl alcohols were 2.48, 5.6, 38.6, 429, and 16.3 mM, respectively. For CAT-1, the values were 697, 55.8, no detectable reaction with propyl and butyl, and 163 mM, respectively. Neither isozyme utilized dianisidine or guaiacol in the peroxidatic reaction. Catalase activity (CAT-2) which eluted in an intermediate position between CAT-1 and CAT-3 from a chromatofocusing column was composed of only one subunit whose Mr coincided with CAT-1, and only the antibody to CAT-1 reacted with CAT-2 protein. Thus, CAT-2 and CAT-1 appear closely related while CAT-3 is distinctly different.
 ...
PMID:Purification and characterization of an isozyme of catalase with enhanced-peroxidatic activity from leaves of Nicotiana sylvestris. 227 60

In maize three isozymic forms of catalase, CAT-1, CAT-2, and CAT-3 are encoded by three distinct and unliked structural genes (Cat1, Cat2 and Cat3). Catalase activity profiles and zymogram analysis were used to examine the spatial and temporal expression of the three genes during kernel maturation. Three developmental stages of catalase expression were observed in the growing kernel. During stage 1 (6-12 days after pollination), both Cat1 and Cat3 were expressed; during stage 2 (15-18 days after pollination) only Cat1 expression was observed; and during stage 3 (21-30 days after pollination), Cat1 and Cat2 were expressed. The major constituent tissues of the kernel were examined to determine their contribution to total kernel catalase expression. Each of the tissues was found to have a unique pattern of catalase gene expression. RNA blot analysis, using catalase gene-specific nucleic acid probes, suggests that the differential expression of the three catalase genes observed in the kernel is regulated by controlling the distribution of steady-state mRNA species for the three genes.
 ...
PMID:Differential expression of the maize catalase genes during kernel development: the role of steady-state mRNA levels. 279 51

Catalase gene expression was characterized in the scutellum of maize seedlings grown at normal (25 degrees C) and elevated temperatures (35 and 40 degrees C). Chronic elevated temperatures reduce scutellar catalase activity most noticeably in the inbred lines W64A and R6-67, which express all three CAT isozymes (CAT-1, CAT-2, and CAT-3). The observed decline in catalase activity is primarily attributed to a decrease in the amount of CAT-2 isozyme, due to diminished levels of the Cat2 transcript. As CAT-2 activity levels are regulated by the trans-acting gene locus Car1, it is possible that the Car1 gene product is inhibited at the elevated temperatures. In maize lines null for CAT-2 or both CAT-2 and CAT-3, the relative levels of Cat1 transcript, although steady throughout the 10 days post-imbibition scutellar profile, are slightly higher with increasing temperatures. This might indicate that, in thermally stressed seedlings, the accumulation and/or stability of Cat1 mRNA might compensate for the lack of Cat2 transcript in a tissue where Cat2 mRNA normally accumulates during the developmental period examined. These observations, along with the drastic reduction in seed germination and seedling height at chronically elevated growth temperatures, suggest that developmental arrest, rather than oxidative stress, might be the cause for the observed results relative to Cat gene expression under such conditions.
 ...
PMID:Catalase gene expression in response to chronic high temperature stress in maize. 1090 10

The effect of high CO(2) (1% CO(2)/21% O(2)) on the activity of specific forms of catalase (CAT-1, -2, and -3) (EA Havir, NA McHale [1987] Plant Physiol 84: 450-455) in seedling leaves of tobacco (Nicotiana sylvestris, Nicotlana tabacum) was examined. In high CO(2), total catalase activity decreased by 50% in the first 2 days, followed by a more gradual decline in the next 4 days. The loss of total activity resulted primarily from a decrease in CAT-1 catalase. In contrast, the activity of CAT-3 catalase, a form with enhanced peroxidatic activity, increased 3-fold in high CO(2) relative to air controls after 4 days. Short-term exposure to high CO(2) indicated that the 50% loss of total activity occurs in the first 12 hours. Catalase levels increased to normal within 12 hours after seedlings were returned to air. When seedlings were transferred to air after prolonged exposure to high CO(2) (13 days), the levels of CAT-1 catalase were partially restored while CAT-3 remained at its elevated level. Levels of superoxide dismutase activity and those of several peroxisomal enzymes were not affected by high CO(2). Total catalase levels did not decline when seedlings were exposed to atmospheres of 0.04% CO(2)/5% O(2) or 0.04% CO(2)/1% O(2), indicating that regulation of catalase in high CO(2) is not related directly to suppression of photorespiration. Antibodies prepared against CAT-1 catalase from N. tabacum reacted strongly against CAT-1 catalase from both N. sylvestris and N. tabacum but not against CAT-3 catalase from either species. This observation, along with the rapid changes in CAT-1 and the much slower changes in CAT-3 suggest that one form is not directly derived from the other.
 ...
PMID:Regulation of Catalase Activity in Leaves of Nicotiana sylvestris by High CO(2). 1666 47