TABLE 2.

Inhibition of pediocin PA-1 by Ped-15-mer fragments in which residues have been replaced with either an alanine or a leucine residue

Replaced residuea	Mean fold inhibition ± SDb
	Alanine replacement	Leucine replacement
K1	4 ± 1	3 ± 1
A2	WT	2 ± 1
T3	70 ± 30	80 ± 30
T4	≥100	2 ± 1
C5	≥100	≥100
I6	55 ± 25	≥100
I7	70 ± 20	≥100
N8	13 ± 4	7 ± 3
N9	60 ± 30	20 ± 10
G10	80 ± 30	40 ± 20
A11	WT	60 ± 20
M12	40 ± 10	65 ± 15
A13	WT	70 ± 30
W14	90 ± 30	80 ± 30
A15	WT	14 ± 6

^aThe residues in the Ped-15-mer fragment which were replaced with alanine and leucine residues are designated by their one-letter abbreviations and a number indicating their position in the fragment, starting from the N terminus. The first residue (K1) in the fragment corresponds to residue 20 (K20) in pediocin PA-1, and so on, with the last residue (A15) in the fragment corresponding to residue 34 (A34) in pediocin PA-1.

^bFold inhibition is the MIC of pediocin PA-1 measured in the presence of a 10 μM concentration of the mutant Ped-15-mer fragment divided by the MIC of pediocin PA-1 measured in the absence of the fragment. The inhibition values presented are the results of at least 3 independent measurements using C. piscicola UI 49 as the indicator strain. The MIC of pediocin PA-1 in the absence of the fragment was 0.3 ± 0.1 nM. WT indicates the wild-type Ped-15-mer fragment (i.e., alanine replaced with alanine), and it resulted in a 60- ± 20-fold inhibition.