Amino Acids In Protein Hydrolysates Research Articles

A Method for Gas Chromatographic Determination of 11 Amino Acids in Protein Hydrolysate

A gas chromatographic method is described by which 11 amino acids in protein hydrolysate can be determined. They are: alanine, aspartic acid, glutamic acid, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline and valine. The result is presented as the percentage of the amino acid in relation to the total weight of amino acids determined. Means of making the method quantitative are indicated.

A simple chromatographic method for determining the basic amino-acids in protein hydrolysates.

A new micro method utilising charcoal chromatography has been developed for the determination of the individual basic amino-acids in protein hydrolysates. It is based on the fact that both the aromatic amino-acids and basic amino-acid picrates are strongly adsorbed by active-charcoal columns, and that the latter can be freed from the aromatic amino-acids by treatment of the adsorbent with aqueous ethyl acetate solution. The separation of the individual basic amino-acids depends on differential decomposition of their picrates on the columns by various eluents. The method can be used for the determination of histidine in the presence of other imidazole derivatives.

Amino acid analysis with fluorodinitrobenzene

A method for the determination of amino acids in protein hydrolyzates is described. The amino acids are converted into their DNP derivatives and fractionated by partition chromatography on columns and on paper, and by paper electrophoresis. The derivatives are estimated spectrophotometrically. The accuracy and reproducibility of the method is discussed.

Separation of proline and hydroxyproline using thin-layer chromatography

Thin-layer chromatography allows rapid separation of proline and hydroxyproline over a wide quantitative range. The present method utilizes the nitrous acid reaction to destroy amino acids in protein hydrolyzates. After ether extraction of amino acid derivatives, proline and hydroxyproline are present unchanged or as unstable n-nitroso derivatives and can be rapidly separated by thin-layer chromatography on cellulose. Mixtures including up to 500 μg of each imino acid are separable on a 250-μ thick layer. The imino acids can be eluted and determined colorimetrically. Studies using isotopically labeled proline and hydroxyproline are possible even when low specific activities are involved. This simple and rapid technique has proved useful in determination of the specific activity of radioactive protein bound hydroxyproline in crude collagen extracts.

Analytical separations by highvoltage paper electrophoresis. Amino acids in protein hydrolysates.

Analytical separations by highvoltage paper electrophoresis. Amino acids in protein hydrolysates.

Amino acid analysis by horizontal paper chromatography

Various modifications of the circular paper chromatographic method for the quantitative determination of amino acids in protein hydrolysates have been investigated. With the system n-butanol -20butanone-water-ammonia (5:3:I:1:) six groups are obtained. Two groups are separated into their individual components with the system lutidine-water, three others wth tert-butanol- formic acid-water (75:0.8:24.2). Threoninc appears as a single band. Lenght of the run is increased and separation is improved by dividing the paper into triangular segments and by putting the starting point near the periphery.

A new technique for the analysis of histidine, tyrosine, methionine and arginine in protein hydrolysates

A technique for the analysis of certain amino acids in protein hydrolyzates is proposed which consists in one-dimensional paper chromatography followed by elution of the proper areas and colorimetric analysis by selective methods. Results are reported for the histidine, tyrosine, methionine, and arginine contents of a few crystalline protein. This method has been applied to the differentiation of some known and unknown strains of TMV. Application to DNP-derivatives of chymotrypsin and DFP-inhibited chymotrypsin has not yielded any evidence concerning the mechanism of the inhibition by the alkyl phosphates.

Qualitative Determination of Amino Acids in Protein Hydrolyzates by Circular Paper Chromatography

Qualitative Determination of Amino Acids in Protein Hydrolyzates by Circular Paper Chromatography

Quantitative determination of amino acids in protein hydrolyzates by paper chromatography

Summary An improved method for the quantitative assay of complex amino acid mixtures has been described. Complete separation of amino acids in simple protein hydrolyzates has been achieved by one-dimensional paper chromatography using a number of alcohol solvents. Direct photometric scanning of these one-dimensional chromatograms subjected to a new modification of the ninhydrin reaction (or isatin reaction in the case of proline) is the basis of the assay. The coefficient of variation for a single determination is ±4.36%. The analysis of bovine serum albumin and of a synthetic mixture of amino acids has been reported.