Purification and biochemical characterization of hepatocyte nuclear factor 2 involved in liver-specific transcription of the human alpha 1-antitrypsin gene.

The upstream region of the human alpha 1-antitrypsin gene binds liver-specific proteins. Two of these proteins, hepatocyte nuclear factors 1 and 2, are essential for liver-specific transcription of this gene. We report for the first time the purification of hepatocyte nuclear factor 2 from rat liver nuclei. This protein, purified to apparent homogeneity by DNA sequence-specific affinity chromatography, appeared on sodium dodecyl sulfate-polyacrylamide gels as a single polypeptide band of molecular mass of 68 kDa. The polypeptide after extraction from the gel matrix and subsequent renaturation bound specifically to the recognition sequences (-88 to -125) and protected the same region of the promoter against DNase I digestion.