TABLE 1.

Average HPV-16 L1 protein yields for the different capsomere constructs^a

L1 capsomere construct	L1 protein yield (mg)/liter of bacterial culture	Amt (EU/mg) of LPS/mg of L1
L1ΔN10	0.27	1,750
L1ΔN10dCys	0.23	2,400
L1ΔN10Δ414-431	0.34	2,900
L1ΔN10Δ408-431	0.41	850
L1ΔN10ΔC29	0.50	860
L1ΔN10dCysΔC29	0.45	780
L1ΔN10Δ414-431ΔC29	0.59	1,450
L1ΔN10Δ408-431ΔC29	0.75	410

^aThe L1 proteins were expressed in and purified from E. coli as described previously by Chen et al. (11). Subsequently, gel filtration chromatography was performed using a Superdex 200 column. Protein amounts were determined by Bradford assay and by densitometry on a Coomassie blue-stained SDS-PAG using the ImageJ software (NIH). LPS contamination was measured using the colorimetric assay QCL-1000 (Lonza). The values in the table are the median values for at least three independent purifications.