CIRCULAR PAPER CHROMATOGRAPHY,· Part TI. Amino Acid Analysis of Proteins

Circular paper chromatographic technique has been applied to the study of the amino acid composition of proteins. Casein, gelatin, zein, silk fibroin, egg albumin, rice and cambn proteins have been subjected to chromatographic analysis and the chromato-graphic patterns showing the amino acid composition of these proteins have been given. By the application of this technique it is shown that proteins can be easily characterised and differentiated with respect to their amitto acid composition. The possible application of this technique to the study of other allied problems is discussed. In Part I (Giri and Rao, 1952), a rapid and simple method for the separation and identification of amino acids by circular paper chromato-graphic technique has been described. In this part of the investigation, the application of this technique to the qualitative analysis of the amino acids of protein hydrolysates will be considered. A brief description of the technique and its application for separation and identification of amino acids from casein hydrolysate has been reported in an earlier publication (Giri, et aI., 1952). It is the purpose of this paper to give further details concerning the separation and identification of the amino acids in a number of proteins using the above technique, to show how proteins can be readily characterised by even visual comparison of the chromatograms of the protein hydro1ysates, to present chromatographic patterns of some protein hydrolysates and to discuss the possible application of this technique to other allied problems. It is shown that by this technique proteins can be characterised sharply enough to provide an adequate method for detecting chemical differences between proteins from different sources. EXPERIMENTAL The basic procedure involved in the separation of amino acids from the protein hydrolysates by circular paper chromato~raphie technique wa