TABLE 2

The ratios of microsomal CYP2B1 and CYP2B1-3A4CT holohemoprotein and total CYP2B1 immunoreactive protein expressed in S. cerevisiae

The genotypes of the yeast strains used are described in Table 1. Yeast were grown in three separate 2L-batches and harvested at the early logarithmic growth stage (see Materials and Methods). The yeast strain RHY718 was transformed with the expression plasmid pYcDE/2B1 (CYP2B1) or pYcDE/2B1-3A4CT (CYP2B1-3A4CT), whereas the yeast strain RHY473 was transformed with plasmid pYES2/2B1 (CYP2B1) or pYES2-ADH/2B1-3A4CT (CYP2B1-3A4CT) as described under Materials and Methods. Microsomes were prepared and subjected to Western immunoblotting analyses as described previously (Murray et al., 2001) with a purified liver CYP2B1 preparation used as the standard for quantification. The P450 spectral content was determined as described previously (Murray et al., 2001). The molar ratio of P450 holocytochrome content/total CYP2B1 immunoreactive protein content is shown.