The reactivity of 4,5',8-trimethylpsoralen with oligonucleotides containing AT sites.
Pyrimidine bases of duplex DNA, of appropriate sequence context, are photoreactive toward 4,5',8-trimethylpsoralen in the presence of long-wavelength UV light. It is generally believed that a 5'-AT site is less photoreactive with psoralen than a 5'-TA site. We have compared the reactivities of these two sites using oligonucleotide duplexes of different sequence context and found that 5'-TA and 5'-AT sites are equally reactive in certain sequences. The presence of alternating pyrimidine and purine (5'-PyATPu-3') bases in oligonucleotide duplexes optimizes the reactivity of 4,5',8-trimethylpsoralen in the 5'-AT sites.
Ramaswamy
M
M
Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111.
Yeung
A T
AT
D000225:Adenine / Q000737:chemistry*; D001483:Base Sequence; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry*; D010777:Photochemistry; D013941:Thymine / Q000737:chemistry*; D014307:Trioxsalen / Q000737:chemistry*
D009841:Oligonucleotides; D000225:Adenine; D013941:Thymine; D014307:Trioxsalen