6.3.4.6 - 1602, 1603 6.3.4.6 copurification of the enzymes involved in urea cleavage, biotin carboxylation, urea carboxylation, and allophanate hydrolysis occur as a complex of enzymes 1606 6.3.4.6 enzyme complex of urea carboxylase and allophanate hydrolase 1607 6.3.4.6 Ni-NTA agarose column chromatography and Sephacryl S-300 gel filtration 727941 6.3.4.6 recombinant 662011