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It was found that fructose 1,6-diphosphate, the main intermediate of glycolysis, was able to act as a coenzyme of yeast phosphoglucomutase reaction. The mechanism of the coenzymatic activity of fructose 1,6-diphosphate was studied. It was indicated in the fructose 1,6-diphosphate dependent reaction that glucose 1,6-diphosphate was formed by the phosphate-transfer of fructose 1,6-diphosphate to glucose 1-phosphate in the first step, and in the second step the conversion of glucose 1-phosphate to glucose 6-phosphate, the original mutase reaction, occurred in the presence of glucose 1,6-diphosphate. The kinetic constants in the reaction of the first step were determined from the time courses of the fructose 1,6-diphosphate dependent reaction.  相似文献   
85.
Endosperm cell walls were isolated from rice grains and their chemical composition was analyzed. The cell walls were composed of cellulose microfibrils and matrix phase which consisted of hemicellulose and pectic substances. Hemicellulose mainly comprised arabinoxylan, accompanied by a small amount of glucose-containing polysaccharide. Pectic substances contained polygalacturonides, some of which had side chains containing neutral sugars such as galactose and arabinose. Amino acid analysis of these fractions suggested that hydroxyproline-containing glycoproteins were contained in these cell walls and firmly bound to cellulose microfibrils.  相似文献   
86.
2-Nitropropane dioxygenase, purified to homogeneity by an improved method from a yeast, Hansenula mrakii, has a molecular weight of 42,000, and consists of a single polypeptide. The enzyme contains 1 mol of FAD per mol of enzyme. The iron protein associated with previous preparations was removed by the present purification procedures. The enzyme catalyzes the oxygenative denitrification of anionic nitroalkanes much more effectively than that of the neutral ones with the optimum pH of 6.5. The Michaelis constants for the anionic substrates are as follows: 2-nitropropane, 1.61 mM; 1-nitropropane, 3.23 mM; nitroethane, 3.13 mM, and 3-nitro-2-butanol, 0.59 mM.  相似文献   
87.
Bovine κ-casein, a phosphoglycoprotein, has mucin-type carbohydrate chains. Subcellular distribution of enzymes that take part in the post-translational modification of κ-casein was examined. In lactating mammary glands from rats and cows, N-acetyl-galactosaminyl transferase, galactosyl transferase, sialyl transferase, and casein kinase were localized specifically in the Golgi apparatus.

The substrate specificities indicate that these enzymes are actually responsible for the processing of κ-casein.

The presence of a phosphate group attached to κ-casein did not affect the rate of glycosylation by N-acetyl-galactosaminyl transferase, while the presence of carbohydrate chains attached to κ- casein strongly reduced the rate of phosphorylation by casein kinase. These results suggest that in the Golgi apparatus, phosphorylation of κ-casein precedes glycosylation.  相似文献   
88.
For rough quantitative analysis of genetically modified maize contents, rapid methods for measurement of the copy numbers of the cauliflower mosaic virus 35S promoter region (P35S) and MON810 construct-specific gene (MON810) using a combination of a capillary-type real-time PCR system with a plasmid DNA were established. To reduce the characteristic differences between the plasmid DNA and genomic DNA, we showed that pretreatment of the extracted genomic DNA by a combination of sonication and restriction endonuclease digestion before measurement is effective. The accuracy and reproducibility of this method for MON810 content (%) at a level of 5.0% MON810 mixed samples were within a range from 4.26 to 5.11% in the P35S copy number quantification. These methods should prove to be a useful tool to roughly quantify GM maize content.  相似文献   
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More than 100 multi-component lures consisting of primary straight chain alkenols, their acetates and alkenals were prepared and tested as attractants of male lepidopterous insects. In field trials, male moths of 52 species were specifically attracted to two- or three-component lures. Further 35 lepidopterous species were found to be attracted to single component lures used as control. The main families captured by the multi-component lures were Tortricidae (24 species), Noctuidae (11 species) and Acrolepiidae (3 species). This successful attraction of so many species indicates the usefulness of systematic field tests using multi-component lures of selected synthetic chemicals.  相似文献   
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