THE AMINO-ACID-COMPOSITION OF MAMMALIAN AND BACTERIAL-CELLS

High performance liquid chromatography was used to analyze the amino a cid composition of cells. A total of 17 amino acids was analyzed. This method was used to compare the amino acid compositions of the followi ng combinations: primary culture and established cells, normal and tra nsformed cells, mammalian and bacterial cells, and Escherichia coli an d Staphylococcus aureus. The amino acid compositions of mammalian cell s were similar, but the amino acid compositions of Escherichia coli an d Staphylococcus aureus differed not only from mammalian cells, but al so from each other. It was concluded that amino acid composition is al most independent of cell establishment and cell transformation, and th at the amino acid compositions of mammalian and bacterial cells differ . Thus, it is likely that changes in amino acid composition due to cel l transformation or species differences between mammalian cells are ne gligible compared with the differences between mammalian and bacterial cells, which are more distantly related.