UV-induced bond modifications in thymine and thymine dideoxynucleotide: structural elucidation of isomers by differential mobility mass spectrometry.
Differential mobility spectrometry has been applied to reveal the occurrence of isomerization of thymine nucleobase and of thymine dideoxynucleotide d(5'-TT-3') due to bond redisposition induced by UV irradiation at 254 nm of frozen aqueous solutions of these molecules. Collision-induced dissociation (CID) spectra of electrosprayed photoproducts of the thymine solution suggest the presence of two isomers (the so-called cyclobutane and 6,4-photoproducts) in addition to the proton-bound thymine dimer, and these were separated using differential mobility spectrometry/mass spectrometry (DMS/MS) techniques with water as the modifier. Similar experiments with d(5'-TT-3') revealed the formation of a new isomer of deprotonated thymine dideoxynucleotide upon UV irradiation that was easily distinguished using DMS/MS with isopropanol as the modifier. The results reinforce the usefulness of DMS/MS in isomer separation.
St-Jacques
Antony
A
Department of Chemistry, Centre for Research in Mass Spectrometry, York University, Toronto, ON, Canada M3J 1P3.
Anichina
Janna
J
Schneider
Bradley B
BB
Covey
Thomas R
TR
Bohme
Diethard K
DK
D054306:Dideoxynucleotides / Q000737:chemistry*; D007536:Isomerism; D013058:Mass Spectrometry / Q000379:methods*; D008968:Molecular Conformation; D013941:Thymine / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays
D054306:Dideoxynucleotides; D013941:Thymine