Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1'-Fluorosucrose (FS), a sucrose analog resistant to hydrolysis by invertase, was transported from husk leaves into maize (Zea mays L., Pioneer Hybrid 3320) kernels with the same magnitude and kinetics as sucrose. (14)C-Label from [(14)C]FS and [(14)C]sucrose in separate experiments was distributed similarly between the pedicel, endosperm, and embryo with time. FS passed through maternal tissue and was absorbed intact into the endosperm where it was metabolized and used in synthesis of sucrose and methanol-chloroform-water insolubles. Accumulation of [(14)C] sucrose from supplied [(14)C]glucosyl-FS indicated that the glucose moiety from the breakdown of sucrose (here FS), which normally occurs in the process of starch synthesis in maize endosperm, was available to the pool of substrates for resynthesis of sucrose. Uptake of FS into maize endosperm without hydrolysis suggests that despite the presence of invertase in maternal tissues and the hydrolysis of a large percentage of sucrose unloaded from the phloem, hexoses are not specifically needed for uptake into maize endosperm.
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PMID:Transport and Metabolism of a Sucrose Analog (1'-Fluorosucrose) into Zea mays L. Endosperm without Invertase Hydrolysis. 1666 28

Metabolomics nowadays mostly comprises the application of both LC-MS and GC-MS based approaches. Here we investigate different extraction set-ups for these two established analytical platforms in the field of plant metabolomics. Six extraction approaches for Arabidopsis thaliana leaves, varying in extraction solvent composition, extraction temperature and order of solvent addition within the extraction sequence, were analyzed on the two platforms. Our aim was to establish the most suitable analysis protocol, practicable for both LC-MS and GC-MS analysis, in order to obtain as extensive as possible metabolome coverage. One single sample preparation procedure would save time and valuable sample while still offering the complementary datasets generated by GC-MS and LC-MS. All extraction approaches were evaluated based on the following criteria: number of detected m/z-retention time pairs, heat maps of the detected peaks, and residual enzymatic activity of invertase and phosphatase in the plant leaf extracts. Unsupervised principal component analysis (PCA) was used to evaluate grouping trends between the different extraction approaches. Quality controls, a blend of aliquots of the different extracts, were used to establish a paired evaluation of the repeatability performance of the GC-MS and LC-MS analysis. We conclude that the use of chloroform in the extraction solvent is counterproductive in an untargeted LC-MS metabolomics approach as is heating. Below room temperature (instead of heated) extraction does not significantly degrade GC-MS performance but one should be more cautious with respect to residual enzymatic activity in the plant extract.
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PMID:Joint GC-MS and LC-MS platforms for comprehensive plant metabolomics: repeatability and sample pre-treatment. 1976 91

1. A method has been outlined by which the enzymes of hemolytic streptococcus may be extracted with comparative ease. 2. The peptolytic enzyme is active between pH 4.4 and 8.7 with an optimum action at pH 7.2. It is destroyed in neutral phosphate solution at a temperature of 57 degrees C. continued for 10 minutes and at pH 5.0 deteriorates slowly at 37 degrees C. Concentration experiments with solutions of the enzyme have shown that it resembles other enzymes. It is exceedingly susceptible to chloroform and its action is inhibited by dilutions of gentian violet. Casein is attacked but serum albumin is not digested after 3 days at 37 degrees C. 3. The invertase is active between approximately pH 5.0 and 8.0 with an optimum of pH 7.0. It is destroyed by a temperature of 52 degrees C. continued 10 minutes at an acid concentration of pH 7.0, or after 6 hours at 37 degrees C. at pH 5.0. At this acidity it is more susceptible to heat than the peptase. 4. The lipase is active above pH 5.6. The greatest activity was observed at pH 7.9. It is completely destroyed after heating to temperatures over 55 degrees C. for 10 minutes and resembles the invertase in its susceptibility to acid.
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PMID:THE PEPTASE, LIPASE, AND INVERTASE OF HEMOLYTIC STREPTOCOCCUS. 1986 48

Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features.
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PMID:Soil microbial biomass, basal respiration and enzyme activity of main forest types in the Qinling Mountains. 2384 Jun 71