General buffer strength

For each enzyme, an optimized buffer solution is provided. Most of the buffers are based on Tris-HCl and have a pH range of 7.4-8.0. All contain magnesium ions as activators for the enzymes. The ionic strength of the buffers is important and different enzymes require different ionic strengths for optimal activity. In general, three strengths of buffer are used low, medium and high, which contain 10, 50 and 100 mol l-1 sodium or potassium chloride respectively. 

Hydrolysis of Salts. Anion hydrolysis cation hydrolysis hydrolysis in general. Buffered solutions. Coordination number of elements formulas of the oxygen acids. Strengths of the oxygen acids. Simple rules. General concepts of acids and bases. Proton donors and acceptors. Acid strength and tendency to undergo condensation. 

Subsequent to the selection of an appropriate column various characteristics of the buflFer were examined. Both pH and buffer strength were varied and retention time was measured. The results are presented in Table II. Generally it was found that a decrease in buffer strength or an... 

In general, the buffer species and the buffer strength will influence the rate of deamidation. High solvent dielectrics favor deamidation. 

The quality of NMR spectra of proteins can be strongly influenced by sample pH, ionic strength, buffer, concentration and temperature optimum conditions are generally determined empirically via ID spectra. For NMR, solutions are generally buffered, at 10-50 mM, with phosphate (which can cause precipitation or aggregation of some proteins) or with deuterated buffer salts (e.g. Tris). Deuterated reducing agents, cation chelators and proteolytic enzyme inhibitors may also be incorporated as necessary. 

For many proteins, a simple buffer such as 0.1M phosphate, pH 7, produces excellent separations on SynChropak GPC columns. Generally, minimal interaction is achieved when the ionic strength is 0.05-0.2 M. To prevent denatur-ation or deactivation of proteins, the pH is generally kept near neutrality. For denatured proteins, 0.1% sodium dodecyl sulfate (SDS) in 0.1 M sodium phosphate, pH 7, is recommended. 

That the reaction was not catalysed by the buffer anion is shown by the data in Table 197, which gives the rate coefficients observed klob, and the rate coefficients ky corr corrected for difference in pH and ionic strength to values of 6.70 and 0.14 respectively. The existence of the general acid-catalysed mechanism for the reaction was demonstrated by the data in Table 198, which gives the rate coeffi-... 

One can test for general acid-base catalysis by varying [BH+] and [B] at constant pH. An easy test is to dilute the buffer progressively at a constant ratio of [BH+]/[B], making up any ionic strength change so as not to introduce a salt effect. If the rate is invariant with this procedure, then general acid-base catalysis is absent under the circumstances chosen. 

Hydration of compounds 2, 3, 4, 5 was found to be first order both in substrate and in hydronium ion (4-10). Furthermore, a careful kinetic study of compounds 2c-g and the sulfur analog 4 revealed that the hydration rate at constant ionic strength was dependent on the buffer concentration and hence was general acid catalyzed. 

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