. 2016 Sep 12;6:33195. doi: 10.1038/srep33195

Table 1. Impact of amino acid substitutions on CphA function in imipenem hydrolysis and resistance.

Category	Residueposition	Amino acid substitution	MIC_IMP (μg/ml)	Imipenem hydrolysis kinetics^a
Category	Residueposition	Amino acid substitution	MIC_IMP (μg/ml)	k_cat (s⁻¹)	K_m (μM)	k_cat/K_m (s⁻¹ μM⁻¹)
		WT	2	2144	310	6.91
Group 1	Gly84	Ala	0.5	510	119	4.35
	Gly84	Asp	0.5	28	209	0.14
	Thr197	Leu	0.38	40	308	0.13
	Thr197	Ser	0.75	1512	371	4.10
	Asp199	Glu	0.75	365	188	1.95
	Lys224	Arg	0.25	>440	>800	0.87
	Gly232	Ala	0.5	>274	>800	0.77
	Asn233	Ser	1	1802	636	2.86
	Asn233	Gln	0.5	371	633	0.59
	Gly262	Ala	0.38	241	547	0.44
	His263	Ala	0.38	>5	>800	0.012
Group 2	Glu69	Asp	0.38	64	388	0.17
	Glu69	Ser	1	641	525	1.23
	Tyr117	Phe	1	177	216	0.83
		Val	0.5	>145	>800	0.35
		Trp	1	365	245	1.49
	Arg121	Ala	0.25	14	117	0.12
	Arg121	Lys	0.75	>750	>800	3.38
	Asn220	Gly	0.75	562	84	6.70
		Leu	0.38	1.63	221	0.007
		Gln	0.5	796	164	4.90
Group 3	Ala195	Gly	1.5	ND	ND	ND
	Pro198	Glu	2	887	182	4.95
	Ser235	Gly	2	ND	ND	ND

^aData are mean results of at least two independent experiments and standard deviations are within 20% of the means; ND, not determined.