Interchain cross-linking of DNA mediated by the principal adduct of acrolein

A DNA duplex containing the primary acrolein adduct, 3-(2-deoxy-beta -D-ery thro-pentofuranosyl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a]purin-10(3H )-one (2), of deoxyguanosine in a 5'-CpG sequence context spontaneously but reversibly formed an interchain cross-link with the exocyclic amino group of deoxyguanosine in the opposing chain. The linkage was sufficiently stabl e that the cross-linked duplex could be isolated by HPLC and characterized by MALDI-TOF mass spectrometry. Enzymatic degradation gave his-nucleoside 6 , which was independently prepared by direct reaction of 2 with dGuo.