Glutamic acid tyrocidine

Gramicidin contains no acidic or basic groups. Tyrocidine contains strongly basic groups due to ornithine residues. It can be isolated only as the hydrochloride. The crystalline mixture tyrocidine contains 1-omithine, 1-proUne, 1-valine, 1-leucine, d-phenylalanihe, 1-tryptophane, 1-tyrosine, 1-aspartic acid and 1-glutamic acid (11). 

Fig. 1. Release of glutamic acid from Strep, faecalis by the action of tyrocidin. Curves 1, glutamic acid assay on intact cell suspension 2, effect of addition of tyrocidin (0.6 mg./lOO mg. dry wt. of cells) at time indicated by arrow 3, as (2) with tyrocidin added = 1.2 mg./lOO mg. dry wt. cells 4, as (2) with tyrocidin added = 2.0 mg./lOO mg. dry wt. cells 5, glutamic acid assay on cell suspension after mechanical disintegration or treatment at 100 for 15 min. (Gale and Taylor, 1947a.)...

---