Van Slyke reaction

One obvious reaction that proteins may undergo when exposed to nitrite is with the a-amino group (Van Slyke reaction). 

Nitrite can also react with ammonia to form ammonium nitrite which is stable in alkaline media but unstable under acid conditions. It decomposes to liberate nitrogen gas. This reaction, which is similar to or identical with the Van Slyke reaction discussed above, has been emphasized by many workers over the years. There is still little quantitative data that characterize the reaction with respect to concentration, temperature, pH, and effects of catalysts (Wilson, 1943 AlUson, 1966). Most recent workers, with the notable exception of Gerretsen and De Hoop (1957), seem to agree that there is no good evidence that loss of gaseous nitrogen via ammonium nitrite decomposition is likely to be... 

They do not react with ninhydrin in the Van Slyke reaction (186, 216). 

The present process is based in large part upon that of Van Slyke and Baker, the modifications depending upon the observation that casein forms far more soluble compounds with univalent than with bivalent bases at neutral reactions. 

Carbon dioxide is not a common oxidation product in periodate work, but it does appear in the oxidation of ketoses,49 a-keto acids,14,39 and a-hydroxy acids,14 39 and it is often a product23 141 of overoxidation. Carbon dioxide analyses have been carried out using the Plantefol apparatus,49 the Warburg apparatus,14 23 and the Van Slyke-Neill mano-metric apparatus,39 and by absorption in standard sodium hydroxide141 followed by back-titration with acid. A most convenient method is the very old, barium hydroxide absorption scheme.16 The carbon dioxide is swept from the reaction mixture into a saturated, filtered barium hydroxide solution by means of a stream of pure nitrogen. The precipitated barium carbonate is filtered, dried, and weighed. This method is essentially a terminal assay. The manometric methods permit kinetic measurements, but involve use of much more complicated apparatus. 

The improved methods introduced in the years 1940 to 1945 created new possibilities in this field. The Van Slyke method for quantitative determination of amino acids, based on the measurement of the volume of carbon dioxide evolved in the course of the reaction between amino acids and ninhydrin (V2), was much more reliable than the older methods. At the same time the microbiological methods designed for amino acid determinations (D3, S6) made possible the detection of very small concentrations of these compounds. The application of these... 

Henri and Michaelis-Menten kinetics assumed that the rate of formation of products was much less than that for the back reaction from ES to yield E + S. Van Slyke assumed the reverse. A more rigorous formulation was offered by Briggs and Haldane (1925) using steady-state assumptions previously applied to chemical kinetics by Bodenstein (1913). 

Problem 36.15 The reaction of primary aliphatic amines with nitrous acid gives a quantitative yield of nitrogen gas, and is the basis of the Van Slyke determination of amino nitrogen. What volume of nitrogen gas at S.T.P. would be liberated from 0.001 mole of (a) leucine, (b) lysine, (c) proline — ... 

It is important for different purposes to be able to express quantitatively the buffer capacity of a liquid. In this connection, a paper by Donald D. van Slyke "On the Measurements of Buffer-values and on the Relationship of Buffer-value to the Dissociation Constant of the Buffer and the Concentration and Reaction of the Buffer Solution will be summarized briefly in the following paragraphs. 

Most GC determinations of primary amino groups in organic compounds (see, for instance, refs. 103-107) are based on a widely known deamination reaction used first for the determination of amines by Van Slyke [108]. A study of the kinetics and stoichiometry of the reaction showed that for quantitative analysis the reaction conditions must be chosen in accordance with the type of organic compounds to be analysed and the correctness of the procedure must be checked with the aid of model compounds [15]. 

Van Slyke s nitroua acid procedure (24), by the fonnol titmtion (25), or by use of the ninhydrin reaction (Sffi). These three methods do not always give the same value. The nitrous acid method probably gives the best value for the total amino nitrogen. The o-amino group may be expected to be titrated between pH 7.0 and 9.0, whereas that of the -amino nitrogen of lysine is nearer pH 8.6>11.5. 

Cohn (161) reported that he and Hughes had succeeded in guanidinating bovine and horse serum albumin with 0-methyl iso urea. These derivatives were immunologically similar to the imtreated protein. Hughes (377) has found that an alkalinity of pH 10.0 was necessary for this reaction. It was practically complete in a few days at 0°C., as determined hy the Van Slyke amino nitrogen method. Greenstein (162), for an entirely differ t purpose, exposed solutions of e albumin to fairly hi ... 

Van Slyke, D. D. (1922) On the measurement of buffer values and on the relationship of buffer value to the dissociation constant of the buffer and the concentration and reaction of the buffer solution. J. Biol. Chem., 52, 525-70. 

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