Figure 3.

Analysis of carboxylase isolated from a r-carboxylase BHK cell line. (A) Solubilized microsomes were prepared from r-carboxylase BHK cells cultured in the presence or absence of vitamin K (vit K). Duplicate samples (50 μg) were incubated in an in vitro protein carboxylation reaction for 1 h and then processed by using SDS/PAGE and PhosphorImager analysis. (B) Carboxylase (≈200 ng) purified from the solubilized microsomes by chromatography on an α-C-terminal carboxylase peptide Ab column was analyzed by SDS/PAGE and silver staining.