High yield purification of Helicobacter pylori neutrophil-activating protein overexpressed in Escherichia coli

Table 1 Purification summary table of recombinant HP-NAP expressed in E. coli ^a

Purification step	Total protein (mg) ^b	Volume (ml)	Purity (%) ^c	Amount of HP-NAP (mg) ^d	Step recovery of HP-NAP (%) ^e	Total recovery of HP-NAP (%) ^f
Whole cell lysate	26.70	20.00	69.45	18.54	100	100
Supernatant	28.60	20.00	73.34	20.98	113	113
DEAE Sephadex chromatography	19.78	59.95	95.97	18.98	90.5	102
Dialysis	18.54	57.95	97.12	18.01	94.9	97.1
Acrodisc syringe filtration	15.33	56.79	99.32	15.23	84.6	82.1

^aFrom 0.115 g of E.coli cell paste obtained from 50 ml culture.
^bProtein concentration determined by the Bradford method with bovine serum albumin (BSA) as the reference.
^cValues determined from densitometry measurement as described in Methods.
^dValues determined by multiplying the values in the column of “Total protein” and “Purity”.
^eValues determined by dividing the amount of HP-NAP from each purification step by that from the previous step.
^fValues determined by dividing the amount of HP-NAP from each purification step by that from the whole cell lysate.

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