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C. van Sumere H. Geiger D. Bral G. Fockenier K. Vande Casteele M. Martens R. Hanselaer L. Gevaert 《Analytical biochemistry》1983,131(2):530-532
The freeze-drying of biological material, which is to be quantitatively analyzed (micro-amount level) for compounds of low or intermediate molecular weight, should be either omitted or handled under strict control. This is because compounds such as amino acids, sugars, flavonoids, glycosides, coenzymes, peptides, etc., might be removed from concentrates and (or) the ground biological material by the high vacuum. 相似文献
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Temmink Ralph J. M. Dorenbosch Martijn Lamers Leon P. M. Smolders Alfons J. P. Rip Winnie Lengkeek Wouter Didderen Karin Fivash Gregory S. Bouma Tjeerd J. van der Heide Tjisse 《Hydrobiologia》2021,848(17):3987-3999
Hydrobiologia - Aquatic ecosystems provide vital services, and macrophytes play a critical role in their functioning. Conceptual models indicate that in shallow lakes, plants with different growth... 相似文献
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Anna P. Florentino Inês A. C. Pereira Sjef Boeren Michael van den Born Alfons J. M. Stams Irene Sánchez-Andrea 《Environmental microbiology》2019,21(1):209-225
Many questions regarding proteins involved in microbial sulfur metabolism remain unsolved. For sulfur respiration at low pH, the terminal electron acceptor is still unclear. Desulfurella amilsii is a sulfur-reducing bacterium that respires elemental sulfur (S0) or thiosulfate, and grows by S0 disproportionation. Due to its versatility, comparative studies on D. amilsii may shed light on microbial sulfur metabolism. Requirement of physical contact between cells and S0 was analyzed. Sulfide production decreased by around 50% when S0 was trapped in dialysis membranes, suggesting that contact between cells and S0 is beneficial, but not strictly needed. Proteome analysis was performed under the aforementioned conditions. A Mo-oxidoreductase suggested from genome analysis to act as sulfur reductase was not detected in any growth condition. Thiosulfate and sulfite reductases showed increased abundance in thiosulfate-reducing cultures, while rhodanese-like sulfurtransferases were highly abundant in all conditions. DsrE and DsrL were abundantly detected during thiosulfate reduction, suggesting a modified mechanism of sulfite reduction. Proteogenomics suggest a different disproportionation pathway from what has been reported. This work points to an important role of rhodaneses in sulfur processes and these proteins should be considered in searches for sulfur metabolism in broader fields like meta-omics. 相似文献
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Isolation of an enzymatically active tissue kallikrein from human seminal plasma by immunoaffinity chromatography 总被引:1,自引:0,他引:1
A tissue kallikrein from human seminal plasma was isolated by immunoaffinity chromatography and characterized. Its molecular mass was determined by gel filtration to be approximately 40000 Da. The enzyme preparation liberates kinin from human HMW kininogen (specific activity: 0.594 HMW kininogen-U/mg), lowers the blood pressure of dogs after intravenous injection (specific activity: 1740 biol. kallikrein unit/mg) and is strongly inhibited by aprotinin but not by soybean trypsin inhibitor. N alpha-Acetyl-L-phenylalanyl-L-arginine ethyl ester, D-valyl-L-leucyl-L-agrine ethyl ester and N-benzyloxycarbonyl-L-tyrosine p-nitrophenyl ester are cleaved with identical rates by the enzyme from human seminal plasma and human urinary kallikrein. 相似文献