Sequence specificity in aflatoxin B1--DNA interactions.

K F Muench; R P Misra; M Z Humayun

doi:10.1073/pnas.80.1.6

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Sequence specificity in aflatoxin B1--DNA interactions.

K F Muench·R P Misra·M Z Humayun

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Abstract

The activated form of aflatoxin B1 (AFB1) causes covalent modification primarily of guanine residues, leading to alkali-labile sites in DNA. A simple extension of the Maxam-Gilbert procedure for sequence analysis permits the identification of alkali-labile sites induced by AFB1 and determination of the frequency of alkali-labile AFB1 modifications at particular sites on a DNA fragment of known sequence. Using this strategy, we have investigated the influence of flanking nucleotide sequences on AFB1 modification in a number of DNA fragments of known sequence. Our results show that certain guanine residues in double-stranded DNA are preferentially attacked by AFB1 over others in a manner predictable from a knowledge of vicinal nucleotide sequences. The observed in vitro sequence specificity is independent of a number of tested parameters and is likely to occur in vivo.

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Aflatoxins Bacteriophage phi X 174 Base Sequence Binding Sites DNA Guanine Plasmids Journal Article Research Support, U.S. Gov't, P.H.S.

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K F Muench, R P Misra, M Z Humayun. 1983. Sequence specificity in aflatoxin B1--DNA interactions.. https://doi.org/10.1073/pnas.80.1.6

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