Chromatography of hydroxysteroid dehydrogenases.

The structure-function study of hydroxysteoid dehydrogenases has stimulated the development of their chromatography, which in turn reveals more mechanisms of these enzymes. Due to the various membrane associations and mild hydrophobic nature of most of the enzymes studied up to now, hydrophobic interaction chromatography has played a crucial role in their purification, using media such as phenyl-Superose or Sepharose-PEG. At the same time, affinity chromatography, especially the dye-containing columns, proves very efficient for these dehydrogenases, as the latter utilizes adenylyl-containing cofactors. Elution by their specific ligand facilitates their purification. In this paper, the use of detergents in the purification of these enzymes is also reviewed. Hydroxysteroid dehydrogenase preparation is further improved by rapid purification which facilitates the elimination of protein microheterogeneity, caused in vitro by oxidation, reduction or partial proteolysis. This process was shown to increase the crystallizability of the enzymes [Lin et al., J. Cryst. Growth, 122 (1992) 242-245; Zhu et al., J. Mol. Biol., 234 (1993) 242-244]. The fast purification permitted a simpler procedure and better combination of various columns than conventional chromatography. This leads to even higher efficiency, yielding homogeneous and highly active preparations.