Table 2.

Steady-State Carbonic Anhydrase Activity in COS-7 Cells Cotransfected with Wild-Type and p.Ser233Pro Mutant CA-VA and β-Glucuronidase

Enzymes	Specific Activity (EU/mg Cell Protein)	Specific Activity Minus Vector (EU/mg Cell Protein)	Percent of WT CA-VA	BGUS Activity (EU/mg)	Transfection Efficiency
PCXN vector only	0.28	0.00	0	37.5	1
WT	1.88	1.60	100	7070	188.5
MT	0.60	0.32	20	8550	228

Values represent the average of two transfections; the enzyme activities were determined in duplicate and calculated as enzyme unit (EU) per milligram (mg) of enzyme protein. The specificity of the assay was verified with the CA-specific inhibitor acetazolamide (500 nM). Abbreviations are as follows: WT, wild-type; MT, mutant.