TY - JOUR
T1 - DNA Sequence Specificity of the Pyrrolo[l,4]benzodiazepine Antitumor Antibiotics. Methidiumpropyl-EDTA-Iron(II) Footprinting Analysis of DNA Binding Sites for Anthramycin and Related Drugs
AU - Hertzberg, Robert P.
AU - Hecht, Sidney M.
AU - Reynolds, Vincent L.
AU - Hurley, Laurence H.
AU - Molineux, Ian J.
PY - 1986
Y1 - 1986
N2 - Anthramycin, tomaymycin, and sibiromycin are members of the pyrrolof 1,4] benzodiazepine [P(1,4)B] antitumor antibiotic group. These drugs bind covalently through N2 of guanine and lie within the minor groove of DNA [Petrusek, R. L., Anderson, G. L., Garner, T. F., Fannin, Q. L., Kaplan, D. J., Zimmer, S. G., & Hurley, L. H. (1981) Biochemistry 20, 1111–1119]. The DNA sequence specificity of the P(1,4)B antibiotics has been determined by a footprinting method using methidiumpropyl-EDTA-iron(II) [MPE'Fe(II)], and the results show that each of the drugs has a two to three base pair sequence specificity that includes the covalently modified guanine residue. While 5'PuGPu is the most preferred binding sequence for the P(l,4)Bs, 5'PyGPy is the least preferred sequence. Footprinting analysis by MPE-Fe(II) reveals a minimum of a three to four base pair footprint size for each of the drugs on DNA with a larger than expected offset (two to three base pairs) on opposite strands to that observed in previous analyses of noncovalently bound small molecules. There is an extremely large enhancement of MPE.Fe(II) cleavage between drug binding sites in AT rich regions, probably indicating a drug-induced change in the conformational features of DNA which encourages interaction with MPE•Fe(II). In the presence of sibiromycin or tomaymycin the normally guanine-specific methylene blue reaction used in Maxam and Gilbert sequencing cleaves at other bases in defined positions relative to the drug binding sites. Finally, modeling studies are used to rationalize the differences and similarities in sequence specificities between the various drugs in the P(1,4)B group and their reactions with DNA.
AB - Anthramycin, tomaymycin, and sibiromycin are members of the pyrrolof 1,4] benzodiazepine [P(1,4)B] antitumor antibiotic group. These drugs bind covalently through N2 of guanine and lie within the minor groove of DNA [Petrusek, R. L., Anderson, G. L., Garner, T. F., Fannin, Q. L., Kaplan, D. J., Zimmer, S. G., & Hurley, L. H. (1981) Biochemistry 20, 1111–1119]. The DNA sequence specificity of the P(1,4)B antibiotics has been determined by a footprinting method using methidiumpropyl-EDTA-iron(II) [MPE'Fe(II)], and the results show that each of the drugs has a two to three base pair sequence specificity that includes the covalently modified guanine residue. While 5'PuGPu is the most preferred binding sequence for the P(l,4)Bs, 5'PyGPy is the least preferred sequence. Footprinting analysis by MPE-Fe(II) reveals a minimum of a three to four base pair footprint size for each of the drugs on DNA with a larger than expected offset (two to three base pairs) on opposite strands to that observed in previous analyses of noncovalently bound small molecules. There is an extremely large enhancement of MPE.Fe(II) cleavage between drug binding sites in AT rich regions, probably indicating a drug-induced change in the conformational features of DNA which encourages interaction with MPE•Fe(II). In the presence of sibiromycin or tomaymycin the normally guanine-specific methylene blue reaction used in Maxam and Gilbert sequencing cleaves at other bases in defined positions relative to the drug binding sites. Finally, modeling studies are used to rationalize the differences and similarities in sequence specificities between the various drugs in the P(1,4)B group and their reactions with DNA.
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U2 - 10.1021/bi00354a009
DO - 10.1021/bi00354a009
M3 - Article
C2 - 3008824
AN - SCOPUS:0022552540
SN - 0006-2960
VL - 25
SP - 1249
EP - 1258
JO - Biochemistry
JF - Biochemistry
IS - 6
ER -