Sulfactase

Sulfactase is a term used in some scientific writings to denote enzymes that hydrolyze sulfur-containing ester or sulfonate bonds, thereby removing sulfate groups from substrates. It is not part of the standard enzyme taxonomy, and it is not an EC-listed class. In mainstream biochemistry, sulfatases (EC 3.1.6.-) describe enzymes that cleave sulfate esters, and most databases and textbooks use that term exclusively. Consequently, sulfactase is considered nonstandard or historical, and its exact meaning can vary among sources.

In practice, when sulfactase is used, it is often as a loose or informal reference to sulfatase-type activities or to hypothetical enzymes that act on organosulfur substrates. Some authors have used the term to describe hydrolases that cleave sulfur-oxygen bonds in sulfated compounds, releasing inorganic sulfate and the corresponding alcohol or phenol. However, without formal consensus, the scope and substrate range of sulfactases remain undefined, and there is no universally recognized list of sulfactase enzymes.

Research on sulfated compound metabolism typically falls under sulfatases or sulfatase-like enzymes discovered in bacteria, mammals, and plants. Studies focus on substrate specificity, active-site chemistry, and physiological roles of sulfur metabolism, rather than on a separate sulfactase family. As such, most current information directs readers to sulfatase literature for mechanism and classification.

See also sulfatase.