Potassium phosphate buffer, solution

An amount of enzyme preparation equivalent to 900 mg of wet cells was made up to 25 ml with the above potassium phosphate buffer solution. 150 mg (1.15 mmol) of 5-fluorouracil and 1.0 gram of thymidine (4.12 mmol) were dissolved in 15 ml of the above potassium phosphate buffer solution. The mixture was incubated at 37°C for 18 hours. After this time, enzyme action was stopped by the addition of four volumes of acetone and one volume of peroxide-free diethyl ether. The precipitated solids were removed by filtration, and the filtrate was evaporated under nitrogen at reduced pressure until substantially all volatile organic solvent had been removed. About 20 ml of aqueous solution, essentially free of organic solvent, remained. This solution was diluted to 100 ml with distilled water. 

Microbial biomass was harvested by centrifugation (5000 rpm, 10 min) and 30 g (wet weight) was transferred to clean 500 mL conical flasks containing 200 mL of 0.2 ionic strength potassium phosphate buffer solution at pH 6.0. 

TABLE 1 Comparisou of the In Vitro Photophysical and Photochemical Parameters of the Excited Singlet State of 64 kDa, 114/118 kDa and 124 kDa Pr Phytochrome from Oat at 275-278 K in Potassium Phosphate Buffer Solution Containing Ethylene Glycol... 

Potassium phosphate buffer solution. Similar l , data were obtained also for SYL-boundb Pr in tris(hydroxymethyl)aminomethane buffer solution. 

PPEG = potassium phosphate buffer solution with 25% (v/v) ethylene glycol in H20 and ethylene glycol-D6 in D20, respectively. 

An amount of enzyme preparation equivalent to 900 mg of wet cells was made up to 25 ml with the above potassium phosphate buffer solution. 150 mg (1.15 mmol) of 5-fluorouracil and 1.0 gram of thymidine (4.12 mmol) were dissolved in 15 ml of the above potassium phosphate buffer solution. 

FIGURE 9.5 Amperograms at a glassy carbon electrode modified with hemoglobin adsorbed in mesoporous molecular sieves MSU/Hbjj/PDDA upon successive additions of 10 iM H2O2 to 0.2 M potassium phosphate buffer solution at pH 6.9. Applied potential -0.30 V vs. SCE. (Adapted from Sun et al., 2008. Talanta 74,1692-1698.)... 

Comparatively, less-studied system is the peroxidase-catalyzed oxidations. One such example is the enantioselective oxidation of phenylmethylsulfide catalyzed by chloroperoxidase from Caldariomyces fumago in several buffer-IL mixtures at different pH values (Scheme 10.12) [107]. In this case, the chloroperoxidase-catalyzed sulfoxidation showed 70% product yield and above 99% ee, in ILs like [MMIM] [Me2P04] and cholinium acetate and cholinium citrate. But for the same sulfoxidation reaction catalyzed by chloroperoxidase, complete loss of enzyme activity was observed in morpholine containing ILs and [MMIM][MeSOJ [107]. The authors have pointed out that the addition of IL to the reaction medium influences the pH level and enzyme activity. For example, addition of 30% (vol/vol) [MMIM] [Me PO J increases the pH of a potassium phosphate buffer solution from 2.7 to 3.7. Enzyme activity of chloroperoxidase was significantly reduced at pH 2.7 which was recovered by increasing the pH to 3.7. (Note The authors have chosen potassium... 

Figure 15.3 (a) Heat absorption in solutions of native RNase A (trace 1) and RNase A kept in 10% buffered formalin for 2 days (trace 2) and 6 days (trace 3) at pH 7.4 and 23°C. All samples were dialyzed against 75 mM potassium phosphate buffer (pH 7.4) prior to DSC. (b) Dependence of Td of the dialyzed RNase A samples on time of incubation in 10% buffered formalin at pH 7.4 and 23°C. (c) Heat absorption of solutions of formalin-treated RNase A fractions isolated by size-exclusion gel chromatography monomer (trace 1), dimmer (trace 2), and a mixture of oligomers with >5 cross-linked proteins (trace 3). Protein concentrations were 0.5 mg/mL. The thermal denaturation transition temperature (Td) is defined as the temperature of the maximum in the excess heat absorption trace associated with the protein s endothermic denaturation transition. See Rait et al.10 for details. 

Certain solubility factors are to be considered in work with periodate at different pH values. Above pH 5, disodium paraperiodate (Na2HJ06) tends to crystallize from aqueous solutions.246 Below pH 5, the sodium salt of periodic acid is more soluble, whereas above pH 5, the potassium salt is best employed. Phosphate-buffer solutions cause erroneous results,23 69a 60 61 and should be avoided in oxidations of carbohydrates. 

Bring the reduced cytochrome c solution to a final volume of 4.5 mL with 50 mM potassium phosphate buffer. 

Prepare a solution of 5 m 3-cyanopyridine (320 mL) to be used as substrate for nicotinic acid preparation in 0.1 m potassium phosphate buffer pH 8.0. 

Ketoreductase enzymes KRED-104 (120mg) and KRED-108 (30mg) and NADP+ (30 mg) were added to 0.5 m potassium phosphate buffer pH 6.5 (9.5 niL) that was stirring at 35 °C. The reaction was started with the addition of a solution of ketone substrate (100 mg) in isopropanol (0.5 mL) and aged for 12h. 

M potassium phosphate buffer, pH 7 aqueous glucose solution ketoreductase enzyme (Codexis Inc) glucose dehydrogenase enzyme (Codexis Inc) methyl tert-butyl ether (MTBE)... 

For each Biocatalytics (Codexis Pasadena) ketoreductase enzyme, 50 pF each of the substrate, cofactor and glucose solutions were added to 350 pF 0.1m potassium phosphate buffer pH 7, 1 mg ketoreductase and 1 Mg glucose dehydrogenase enzymes in one location of a 96-well plate. 

Stock solution 5. 1 m stock solution of potassium phosphate buffer was prepared by dissolving K2HP04-3H20 (11.423 g) and KH2PO4 (6.805 g) in deionized water to a final volume of 100 mL. The pH was adjusted to 7.0. This 1 m stock solution was diluted to the desired concentration of 50 mM with deionized water. Buffers were stored at 0-4 °C. 

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