In the blood fluke Schistosoma mansoni a functionally active, monomeric, phospholipid hydroperoxide glutathione peroxidase (PHGPx) has been purified and characterized. This enzyme contains a catalytically active selen...In the blood fluke Schistosoma mansoni a functionally active, monomeric, phospholipid hydroperoxide glutathione peroxidase (PHGPx) has been purified and characterized. This enzyme contains a catalytically active selenocysteine. The protein has been shown to be the product of a cloned gene, previously referred to as a glutathione peroxidase gene. S. mansoni PHGPx has been found 5 times more abundant in female than in male worm extract. As in vertebrate PHGPx, homology alignment indicates that the residues involved in the glutathione binding by the tetrameric cellular glutathione peroxidase are mutated in the S. mansoni enzyme. Thus, this aspect appears a landmark of the PHGPx-type of glutathione peroxidases,which might be of functional relevance展开更多
[Objective] The purpose of this study was to determine the effect of chitosan with different molecular weights on quality and lignification of postharvest Chi- nese chive scapes （Allium tuberosum Rottler ex Sprengel...[Objective] The purpose of this study was to determine the effect of chitosan with different molecular weights on quality and lignification of postharvest Chi- nese chive scapes （Allium tuberosum Rottler ex Sprengel）. [Method] Some physio- logical and biochemical indexes such as weight loss, decay index, opening rate of flowers, chlorophyll and ascorbic acid content, respiration rate, the activities of enzymes, lignin and cellulose content of Chinese chive scapes treated with three kinds of chitosan with different molecular weights were investigated during the room stor- age at 20 ℃ to simulate shelf life. [Result] The results showed that all the treat- ments of chitosan with different molecular weights significantly delayed weight loss, decay index and opening rate of flowers, maintained higher chlorophyll and ascorbic acid content, inhibited respiration rate, reduced the activities of enzymes phenylala- nine ammonia lyase, cinnamyl alcohol dehydrogenase and peroxidase, and retarded lignin and cellulose accumulation during the storage of Chinese chive scapes. However, high molecular weight chitosan has better preservation effect on Chinese chive scapes. [Conclusion] The results suggest that the coating treatment of high molecu- lar weight chitosan may be a promising technique to maintain postharvest quality of Chinese chive scapes.展开更多
Wheat germ meal is the by production of oil extracting, and a great quantity of it has been wasted, thus the quantity of lost protein is great. In order to use wheat germ meal proteins adequately, wheat germ proteins ...Wheat germ meal is the by production of oil extracting, and a great quantity of it has been wasted, thus the quantity of lost protein is great. In order to use wheat germ meal proteins adequately, wheat germ proteins were hydrolyzed to anti-oxidation peptides by using alkaline protease. Through the single factor analysis and regression analysis, the optimized experiment conditions of hydrolysising wheat germ meal to wheat germ peptides were enzymatic quantity 0.8%（w/w）, material to liquid ratio 1∶12.3, enzymolysis time 2.1 h. Under these conditions, the scavenging effect was 49.78%,the DH was 22% and peptides content in enzymatic hydrolysate was 1.9%（w/w）.By SDS-PAGE electrophoresis,the molecular weight range of wheat germ peptides were below 10 ku and most were between 4.54 and 5.63 ku.The wheat germ proteins could be used ful y and grain resources would be saved.展开更多
文摘In the blood fluke Schistosoma mansoni a functionally active, monomeric, phospholipid hydroperoxide glutathione peroxidase (PHGPx) has been purified and characterized. This enzyme contains a catalytically active selenocysteine. The protein has been shown to be the product of a cloned gene, previously referred to as a glutathione peroxidase gene. S. mansoni PHGPx has been found 5 times more abundant in female than in male worm extract. As in vertebrate PHGPx, homology alignment indicates that the residues involved in the glutathione binding by the tetrameric cellular glutathione peroxidase are mutated in the S. mansoni enzyme. Thus, this aspect appears a landmark of the PHGPx-type of glutathione peroxidases,which might be of functional relevance
基金Supported by Jiangsu Agriculture Science and Technology Innovation Fund[CX(11)4056]Strategic Key Project of Jiangsu Provincial Science and Technology Development(BE 2012417)~~
文摘[Objective] The purpose of this study was to determine the effect of chitosan with different molecular weights on quality and lignification of postharvest Chi- nese chive scapes （Allium tuberosum Rottler ex Sprengel）. [Method] Some physio- logical and biochemical indexes such as weight loss, decay index, opening rate of flowers, chlorophyll and ascorbic acid content, respiration rate, the activities of enzymes, lignin and cellulose content of Chinese chive scapes treated with three kinds of chitosan with different molecular weights were investigated during the room stor- age at 20 ℃ to simulate shelf life. [Result] The results showed that all the treat- ments of chitosan with different molecular weights significantly delayed weight loss, decay index and opening rate of flowers, maintained higher chlorophyll and ascorbic acid content, inhibited respiration rate, reduced the activities of enzymes phenylala- nine ammonia lyase, cinnamyl alcohol dehydrogenase and peroxidase, and retarded lignin and cellulose accumulation during the storage of Chinese chive scapes. However, high molecular weight chitosan has better preservation effect on Chinese chive scapes. [Conclusion] The results suggest that the coating treatment of high molecu- lar weight chitosan may be a promising technique to maintain postharvest quality of Chinese chive scapes.
文摘Wheat germ meal is the by production of oil extracting, and a great quantity of it has been wasted, thus the quantity of lost protein is great. In order to use wheat germ meal proteins adequately, wheat germ proteins were hydrolyzed to anti-oxidation peptides by using alkaline protease. Through the single factor analysis and regression analysis, the optimized experiment conditions of hydrolysising wheat germ meal to wheat germ peptides were enzymatic quantity 0.8%（w/w）, material to liquid ratio 1∶12.3, enzymolysis time 2.1 h. Under these conditions, the scavenging effect was 49.78%,the DH was 22% and peptides content in enzymatic hydrolysate was 1.9%（w/w）.By SDS-PAGE electrophoresis,the molecular weight range of wheat germ peptides were below 10 ku and most were between 4.54 and 5.63 ku.The wheat germ proteins could be used ful y and grain resources would be saved.
