Tyrosine-ester sulfotransferase from rat liver: bacterial expression and identification

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Background:

• Sulfotransferases are crucial enzymes involved in the metabolism of various compounds.
• Accurate identification and characterization of sulfotransferase isoforms are essential for understanding their physiological roles.

Purpose of the Study:

• To identify and characterize a rat liver sulfotransferase using a cloned nucleotide sequence.
• To investigate the enzymatic activity and substrate specificity of the expressed protein.

Main Methods:

• Gene cloning and expression in Escherichia coli.
• Enzyme purification using polyol solutions.
• Substrate spectrum analysis and peptide sequencing for enzyme identification.
• Antibody specificity testing.

Main Results:

• The expressed protein was identified as tyrosine-ester sulfotransferase (EC 2.8.2.9), not aryl sulfotransferase (EC 2.8.2.1).
• The recombinant enzyme exhibited a broad substrate range, including phenols, hydroxylamines, and tyrosine esters.
• Two isoforms were obtained, requiring polyol solutions for solubilization and purification.

Conclusions:

• The study identified a novel tyrosine-ester sulfotransferase expressed from a previously misidentified gene sequence.
• The recombinant enzyme's broad substrate specificity highlights its potential significance in diverse metabolic pathways.
• The findings provide a foundation for further research into sulfotransferase function and regulation.