SPDPcrosslinker(N-Succinimidyl3-[2-pyridyldithio]-propionate)isacleavable,waterinsoluble,aminoandthiol(sulfhydryl)reactiveheterobifunctionalproteincrosslinker.TheSPDPcrosslinkingreagentcrosslinksproteinorpeptidesviareactivemoitesconsistingofanN-hydroxysuccinimide(NHS)esterthatreactswithprimaryamines,asfoundinlysinesidechainsortheN-terminusofproteinsandpeptides;ontheotherendoftheSPDPcrosslinkingmoleculepyridinyldisulfidereactswithsulhydrylstoyieldarevers
IBLedisulfidebondwhichcanbereducedwithTCEP-HClorDTT.
ProteoChemalsooffersa"longchain"versionoftheSPDPproteincrosslinker.LC-SPDPcrosslinkerhasa15.7angstromspacerarm,comparedtotheshorter6.8angstromspacerarmversionoftheSPDPproteincrosslinker.Often,duetosterichindrances,itisdesirabletoempiricallytestwhichofthetwoversionswillworkbestinyourspecificapplication.