Gramicidin A is an antibiotic produced by Bacillus brevis. It is a linear pentadecapeptide with N-terminal formylation blocking an amino group and C-terminal with an aldehyde group. Gramicidin A can kill some microorganisms. Two short Gramicidin A molecules are inserted relatively from both sides of the membrane to form a transmembrane channel, which improves the permeability of the biofilm to certain monovalent cations and allows these substances to pass through the cell membrane along the concentration gradient, but short Gramicidin A is not significant Increase transportation speed. Studies have shown that Gramicidin A can inhibit the transcription of T7 bacteriophage DNA, inhibit membrane-bound epidermal adenylate phosphatase activity and inhibit the transformation of human lymphocytes in vitro. It can prolong the survival rate of heart transplantation in rat animal models.