Serological Tests with Amino Acids

[摘要] In the course of studies on the immunological specificity of peptides (1, 2) it was found necessary to establish to what extent amino acids which are contained in proteins can be differentiated by immune sera.[1][1]Preparation of Para-Nitro- and Para-Aminobenzoyl Derivatives of Amino Acids. Nitrobenzoylation of the amino acids was mostly carried out by the method used previously for the preparation of p-nitrobenzoyl peptides (2). In the case of histidine a dilute solution of sodium hydroxide was used instead of sodium bicarbonate (3). Phenylalanine and tryptophane were dissolved in a small amount of normal sodium hydroxide before adding sodium bicarbonate. For the nitrobenzoylation of glutamic and aspartic acid the directions given by E. Fischer for the preparation of the benzoyl derivatives were followed (4). The products were freed from nitrobenzoic acid by extraction with ether, and if the nitrobenzoyl amino acid was appreciably soluble in ether, the ether solution was concentrated to a small volume and the substance precipitated by addition of petroleum ether (boiling point 90 to 100°). [1]: #fn-1

[学科分类] 生物科学（综合）