A study has been made of the pH stability of centrifugally purified strains of influenza virus with respect to the biological properties of mouse infectivity and chicken red blood cell agglutinating activity. Observations also were made on the importance of composition of buffer, temperature of storage, and concentration of virus protein to the stability of the virus. When tested for stability ...

The study of electrochemical reactions in seawater requires understanding the associated coupled chemistry with components seawater, especially role carbonate–bicarbonate buffer system case proton-coupled electron transfer reactions. We report comparative paradigmatic voltammetric response reversible hydrogen oxidation reaction absence or presence dibasic phosphate, formate, bicarbonate. Electr...

A direct differentiation of the internal and external drug-deposition pattern into hair was made using two fluorescent dyes and fluorescence microscopy after systemic administration to mice or external exposure of untreated hair. Mice (23 days old, C57 and Balb/C) were administered either rhodamine or fluorescein intraperitoneally at varied doses on 3 consecutive days of 3 weeks, and hair was s...

A L-ascorbic acid biosensor based on ascorbate oxidase has been developed. The enzyme was extracted from the mesocarp of cucumber (Cucumis sativus) by using 0.05 mol L phosphate buffer, pH 5.8 containing 0.5 mol L NaCl. After the dialysis versus phosphate buffer 0.05 mol L pH 5.8, the enzyme was immobilized onto nylon net through glutaraldehyde covalent bond. The membrane was coupled to an O 2 ...

The production of singlet oxygen (O2) by bacteriochlorin a (BCA) was studied in phosphate buffer and in dimyristoyl--α-phosphatidylcholine (DMPC) unilamellar liposomes. The comparative method used to measure O2 production was a quantitative analysis of photooxidation reactions leading to the loss of absorbance of the water-soluble specific probe: anthracene-9,10-dipropionic acid. Rose Bengal, ...

Liu et al. (1) alleged that they could not repeat our work on the protein BBL (Protein Data Bank ID code 1W4H) at the most basic level. Campos and Muñoz now admit (2), as we explained (3), that they used a phosphate buffer that greatly changed pH during the guanidinium chloride (GdmCl) titration relative to our Mops buffer. They can now repeat our work. However, the authors now claim (2), misle...

Carbonic-phosphoric anhydride (carboxy phosphate) is formed on the enzyme when glutamine-dependent carbamyl phosphate synthetase (Escherichia coli) is incubated with ATP, Mg’+, and HCO,,-. Carboxy phosphate may be trapped by borohydride reduction to formate and as the trimethyl derivative by treatment with diazomethane. The rate of enzyme-bound carboxy phosphate formation is evidently extremely...

N-(2-hydroxyethyl)-piperazine-N'-2-ethanesulfonic acid, known as HEPES buffer, with pK in the physiological range was studied for use as an alternative to conventional phosphate buffer for the calibration of pH in modern clinical analyzers. In different series of aqueous equimolar HEPES buffer, pH was measured at 37 degrees C with a capillary glass electrode standardized previously using phosph...

In the horse, drug metabolism has been shown to be complex, but little is known about the proteins involved in these processes [l]. As a result of work on the purification of equine Cytochrome P450 enzymes, an epoxide hydrolase has been purified [2]. Epoxide hydrolases catalyse the hydration of biologically active epoxides formed during the metabolism of many drugs and mutagenic compounds [3]. ...

The molecular interactions of the glycopeptide antibiotic vancomycin (Van) with bacterial cell wall analogues N,N'-diacetyl-L-Lys-D-Ala-D-Ala (Ac(2) KdAdA) and N,N'-diacetyl-L-Lys-D-Ala-D-Lac (Ac(2) KdAdL) were investigated in neat water, phosphate buffer and HEPES buffer by using fluorescence correlation spectroscopy (FCS) and molecular dynamics (MD) simulations. The FCS determined dissociatio...