Introduction:Polypeptidehormonessecretedbytheparathyroidglands,whichpromotereleaseofcalciumfrombonetoextracellularfluidbyactivatingosteoblastsandinhibitingosteoclasts,indirectlypromoteincreasedintestinalabsorptionofcalcium,andpromoterenaltubularreabsorptionofcalciumandincreasedrenalexcretionofphosphates.Itisamajorregulatorofbonemetabolism.Secretionofparathyroidhormoneincreaseswhenthelevelofcalciumintheextracellularfluidislow.Itsactionisopposedbycalcitonin.PTH(7-34),whichisaPTH/PTHrPreceptorantagonist,canstimulatehairgrowthandepidermalproliferationinmice.Description:ParathyroidHormoneHumanRecombinantproducedinE.Coliisasingle,non-glycosylated,polypeptidechaincontaining28aminoacidsandhavingamolecularmassof3380Dalton.ThePTHispurifiedbyproprietarychromatographictechniques.PhysicalAppearance:SterileFilteredWhitelyophilized(freeze-dried)powder.Formulation:Theprotein(1mg/ml)waslyophilizedafterextensivedialysesagainst20mMPBSpH-7.0and150mMNaCl.Solubility:ItisrecommendedtoreconstitutethelyophilizedPTHinsterile18MΩ-cmH2Onotlessthan100µg/ml,whichcanthenbefurtherdilutedtootheraqueoussolutions.StABIlity:LyophilizedParathyrinalthoughstableatroomtemperaturefor3weeks,shouldbestoreddesiccatedbelow-18°C.UponreconstitutionPTHshouldbestoredat4°Cbetween2-7daysandforfutureusebelow-18°C.Forlongtermstorageitisrecommendedtoaddacarrierprotein(0.1%HSAorBSA).Pleasepreventfreeze-thawcycles.Purity:Greaterthan97.0%asdeterminedby:(a)AnalysisbyRP-HPLC.(b)AnalysisbySDS-PAGE.BIOLOGicalActivity:TheactivitycalculatedbyUMR106cell/cAMPmethodcorrespondingtoaspecificactivityof10,000Units/mg.ForLABORATORYRESEARCHUSEONLY.Theproductmaynotbeusedasdrugs,agriculturalorpesticidalproducts,foodadditivesorhouseholdchemicals.