CHROMATOGRAPHIC ANALYSES OF AMINO ACIDS IN THE DEVELOPING SLIME MOLD, DICTYOSTELIUM DISCOIDEUM RAPER

¹ Department of Zoology, Newcomb College of Tulane University, New Orleans 18, Louisiana

1. The amino acids in hydrolyzed and unhydrolyzed tissue of the slime mold, Dictyostelium discoideum Raper, have been determined by means of two-dimensional ascending paper chromatography. Analyses were made on four stages of development—migrating pseudoplasmodium, pre-culmination, culmination, and mature sorocarp.

2. Unhydrolyzed tissue contained the leucines, methionine, tyrosine, alanine, threonine, glycine, serine, glutamic acid, aspartic acid, cystine, and seven unidentified spots, presumably simple peptides. Not all these spots were present in all tested stages.

3. Hydrolyzed tissue contained in addition to the amino acids identified above, phenylalanine, proline, histidine, asparagine, and one unknown spot. All tested stages were identical.

4. The postulate is presented that glutamic acid (and possibly also to a lesser degree aspartic acid, alanine, serine, and cysteine) through deamination may enter the Krebs cycle and form a link between protein and carbohydrate metabolism, the change in balance between protein and carbohydrate being one of the most prominent features of differentiation in this organism.