ABSTRACT
Aadenosine 5-phosphosulfate (APS) and 3-phosphate 5-phosphosulfate (PAPS) occupy a central position in the biochemistry of the sulfate ion in animals, plants and microorganisms. Dissimilatory reduction of sulfate in microorganisms generally involves APS as the activated intermediate, as does assimilatory sulfate reduction in phototrophic bacteria and algae, also. In contrast, PAPS is the activated intermediate in assimilatory sulfate reduction in nonphotosynthetic bacteria and other microorganisms and appears to be the "active sulfate" used by all types of cell in sulfate transfer reactions leading to the formation of sulfate esters. Many animal tissues are known to be able to hydrolyse APS and/or PAPS, and in view of the limited results so far available it seems likely that many microorganisms will prove to possess similar activities. The sinigrin sulfatase enzyme was purified and characterized and has been of value in the quantitative analysis of glucosinolates in leaf and seed tissues of the crucifers.
