Table 1. Binding energy of ligands (antibiotics and AHLs) with His₆-OPH at different pH.

Scoring function named affinity (Trott & Olson, 2010) is an estimated minimum of potential energy during electrostatic and hydrophobic interactions, and hydrogen bonding between ligand (antibiotic or AHL) and receptor (enzyme).

Ligand	pH	Affinity, (kJx mol−1)				p value
		Mean	Median	Range
Puromycin	7.5	−29.9	−30.1  ± 0.8	−29.3	−30.5	0.317
	10.5	−30.3	−30.1  ± 1.0	−29.3	−31.0
Ceftiofur	7.5	−29.7	−29.3  ± 1.2	−29.0	−30.1	0.837
	10.5	−29.8	−29.5  ± 1.3	−29.0	−30.7
C4-HSL	7.5	−21.8	−21.9  ± 1.8	−23.1	−20.7	0.170
	10.5	−22.5	−22.7  ± 0.8	−22.7	−22.0
C8-HSL	7.5	−23.2	−23.2  ± 2.3	−23.9	−22.5	0.206
	10.5	−23.9	−23.4  ± 1.3	−24.5	−22.8
C12-HSL	7.5	−23.8	−23.7 ± 1.2	−24.4	−23.2	0.360
	10.5	−23.5	−23.0  ± 1.1	−24.3	−22.7