TY - JOUR
T1 - AAF linked to the guanine amino group
T2 - A B-Z junction
AU - Hingerty, B.
AU - Broyde, S.
N1 - Funding Information:
This work was supported jointly by American Cancer Society Institutional Grant to New York University, IN-14V (SB), NIH Grant 1R01 CA28038-02 (SB), DOE Contract #DE-ACO1-81 ER6OO15 (SB), and by the Office of Health and Environmental Research, U.S. Department of Energy, under Contract W-7405-eng-26 with the Union Carbide Corporation (BH). We thank Professor Robert Shapiro for many helpful discussions. We also thank Dr. S. Neidle for pointing out that a high torsion barrier for a'is indicated by the short N6-C bond length in the analogous carcinogen-nucleoside adduct N6-(12-methylbenz [a] anthracenyl-7-methyl) deoxyadenosine (28), Indicating partial double bond character for amino linked adducts. Special thanks are due to Dr. K. Lipkowitz for communicating torsion barriers calculated for a' and B' prior to publication.
PY - 1983/5/25
Y1 - 1983/5/25
N2 - Minimized conformational potential energy calculations have been performed for AAF linked to dCpdG at the guanine amino group. This 1s a model for the minor AAF adduct observed in DNA, whose conformational Influence has been difficult to ascertain. A global minimum energy conformation was computed with torsion angles like those of the dCpdG residue of Z-DNA. This conformation was Incorporated into a larger polymer model at a B-Z junction, with the carcinogen residing 1n the groove 1n the Z direction. Local minimum energy conformations of the B type were also computed. In addition, two minima were found with fluorene-cytidine stacking. These results suggest that existing B-Z junctions may be vulnerable to modification by AAF at the guanine amino group, or that such junctions may be Induced by the carcinogen 1f the base sequence 1s appropriate. Otherwise the carcinogen can be located 1n the minor groove of the B helix (5,10,11) or covalently intercalated (13-15).
AB - Minimized conformational potential energy calculations have been performed for AAF linked to dCpdG at the guanine amino group. This 1s a model for the minor AAF adduct observed in DNA, whose conformational Influence has been difficult to ascertain. A global minimum energy conformation was computed with torsion angles like those of the dCpdG residue of Z-DNA. This conformation was Incorporated into a larger polymer model at a B-Z junction, with the carcinogen residing 1n the groove 1n the Z direction. Local minimum energy conformations of the B type were also computed. In addition, two minima were found with fluorene-cytidine stacking. These results suggest that existing B-Z junctions may be vulnerable to modification by AAF at the guanine amino group, or that such junctions may be Induced by the carcinogen 1f the base sequence 1s appropriate. Otherwise the carcinogen can be located 1n the minor groove of the B helix (5,10,11) or covalently intercalated (13-15).
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U2 - 10.1093/nar/11.10.3241
DO - 10.1093/nar/11.10.3241
M3 - Article
C2 - 6856457
AN - SCOPUS:0021112001
SN - 0305-1048
VL - 11
SP - 3241
EP - 3254
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 10
ER -