TABLE 1.

Efficiency of PB1 peptides to compete with PA binding^a

Peptide	Amino acid sequence	Mean IC50 (nM) ± SD
PB11-15	MDVNPTLLFLKVPAQ	41.3 ± 11.1
PB11-11	MDVNPTLLFLK----	1,611.3 ± 281.0
PB15-11	----PTLLFLK----	>10,000*
PB15-11T6Y	----PYLLFLK----	>10,000*
PB15-11T6W	----PWLLFLK----	>10,000*

^aDetermination of the 50% inhibitory concentrations (IC₅₀s) of PB1_1-15-derived peptides by competitive ELISA using cell extract containing HA-tagged PA of A/WSN/33 and increasing concentrations of competitive peptides. Asterisks indicate the highest concentrations of competitive peptides (10,000 nM) used without detectable inhibitory effect. Affinity-enhancing amino acids are highlighted in boldface.