High affinity interaction of mammalian DNA topoisomerase I with short single- and double-stranded oligonucleotides.
The interaction of DNA topoisomerase I (topo I) with a set of single- and double-stranded oligonucleotides containing 5-27 mononucleotides was investigated. All single- and double-stranded oligonucleotides were found to inhibit competitively the supercoiled DNA relaxation reaction catalyzed by topo I. The enzyme affinity for specific sequence pentanucleotides of the scissile (GACTT, Ki = 2 microM) and non-cleaved chain (AAGTC, Ki = 110 microM) is about 2-4 orders of magnitude higher than that for non-specific oligonucleotides. This specific sequence affinity increases in several cases; lengthening of single-stranded oligonucleotides, formation of stable duplexes between complementary oligonucleotides and preincubation of the enzyme with ligands before addition of supercoiled DNA. We assume that oligonucleotides having a high affinity to the enzyme can offer a unique opportunity for rational design of topoisomerase-targeting drugs.
Nevinsky
G A
GA
Novosibirsk Institute of Bioorganic Chemistry, Siberian Division of the Russian Academy of Sciences.
Bugreev
D V
DV
Buneva
V N
VN
Yasui
Y
Y
Nishizawa
M
M
Andoh
T
T
D001483:Base Sequence; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004278:DNA, Superhelical / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism*
D004277:DNA, Single-Stranded; D004278:DNA, Superhelical; D009841:Oligonucleotides; D004264:DNA Topoisomerases, Type I