Improved Mass Analysisof oligoribonucleotides by~(13)C,~(15)N Double Depletion and electrospray Ionizaiton FT-ICR Mass Spectrometry

摘要

~(13)C,~(15)N doubly depleted32-ribonucleotide was synthe-sized enzymatically by in vitro transcription from nucleoside triphosphatesisolated from E.coli grown ina minimal medium containign ~(12)C,~(14)N-enriched glucose and ammonium sulfate.Followign purification and desaltin gby reversed-phase HPLC,bufferexchange with Microcon YM-3,and ethanol precipitation,electrospray ionization Fourie rtrnasform ion cyclotron resonance massspectra revealed greatly enhanced abundance of mono-isotopic ions (by a factor of approx 100) and a narrower isotopic distribution with highe rsignal-to-noise ratio.The abrupt onset and high magnitude of the monisotopic species promise to facilitate accuratemass measurement of RNA's.