Table 2.

Amount of prochymosin produced by E coli W3110 cells expressing gene variants created using different codon optimization methods.

Sequence - expression vector	Codon optimization method	CAIa	Prochymosin produced (mg/l)b	Prochymosin produced (relative to wild type)
Wild type - pWT	-	0.66	262 ±19	1
V0 - pV0	One amino acid- one codon	1	248 ± 17	0.95
V1 - pV1	One amino acid- one codon	0.82	246 ± 21	0.94
V2 - pV2	Codon randomization	0.72	448 ± 31	1.71
V3 - pV3	Codon randomization	0.70	366 ± 26	1.50
V4 - pV4	Codon randomization	0.72	330 ± 16	1.36
V5 - pV5	Codon randomization	0.73	311 ± 20	1.29
V6 - pV6	Codon randomization	0.74	309 ± 29	1.21
V2/0 - pV2/0	Hybrid construct	0.97	296 ± 12	1.13

^a Codon adaptation index.

^b Determined by scanning and densitometry analysis of stained gels. Values shown represent mean and standard error of three independent experiments.

Cells were grown at 30°C in supplemented LB medium to OD₆₀₀ = 0.5 and induced by the addition of 2 g/l of L-arabinose for 5 h.