Aryldialkylphosphatase
Organophosphate is the general name for esters of phosphoric acid and is one of the organophosphorus compounds. They can be found as part of insecticides, herbicides, and nerve gases, amongst others. Some less-toxic organophosphates can be used as solvents, plasticizers, and EP additives. The use of organophosphates accounts for approximately 38% of all pesticide use globally.
Exopolyphosphatase
PPX was discovered by the lab of Nobel laureate Arthur Kornberg in 1993 and is part of the polyphosphate operon along with polyphosphate kinase, the enzyme which synthesizes polyphosphate. The Kornberg lab was very interested in polyphosphate and published a series of papers elucidating the metabolism and roles of polyphosphate "in vivo". Their interest in polyphosphate led them to identify and characterize the polyphosphate operon (which includes polyphosphate kinase [PPK] and PPX) and develop a wide variety of assays and techniques for quantification of polyphosphate production and degradation, "in vitro" and "in vivo". The results of these studies of polyphosphate by the Kornberg lab led Kornberg to speculate that due to its high energy and phosphate content and the degree to which it is conserved across species, polyphosphate may have been the precursor to RNA, DNA, and proteins.