I.U.B.:3.1.3.2
AcidphosphataseisanesterasewithbroadactivityatanoptimalpHbelow7.0.Therearethreeisozymes,EI,EII,andEIIIofsimilarmolecularweight(55kDa±5kDa).TheiroptimumpH"sare5.5,4.5,and4.0respectively.AcidphosphataseactivitywasobservedbyTellerWorthingtonLibraryArchivesin1954inpreparationsofawheatgermlipasedescribedbySingerJBC,174,11,in1948.Equivalentcommercialpreparationshavebeendistributedlabeledaslipaseandacidphosphatasethusgeneratingsomeconfusion.Subsequentworkhasconfirmedthatthenon-specificesteraseactivityofthewheatgermpreparationmaybemeasuredbothaslipase(triacetinassubstrate)andphosphatase.TheenzymeassayisbasedontheworkofBrandenbergerandHanson(Helv.Chim.Acta,36,900,1953)andHofstee(Arch.Biochem.Biophys.,51,239,1954).
UnitDefinition:OneUnithydrolyzesonemicromoleofo-carboxyphenylphosphateperminuteat25°C,pH5.0.
