OBSERVATION OF NONCOVALENT INTERACTIONS BETWEEN BEAUVERICIN AND OLIGONUCLEOTIDES USING ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY

Electrospray ionization mass spectrometry has been used to study the p ossible non-covalent interaction between oligonucleotides and beauveri cin (B) mycotoxin. Beauvericin-oligonucleotide adduct formation was ob served even at low mycotoxin concentration (25pmol/mu L). Adducts were found with different numbers of B ligands attached. The selectivity o f binding of B ligands to two different oligonucleotides has been show n to be similar indicating that beauvericin does not have a strongly p referred base sequence or base site in the DNA. In a competitive compl exation reaction, beauvericin forms specific adducts with oligonucleot ide while another mycotoxin, nigeromicin, which causes apoptosis witho ut fragmentation of DNA, does not. (C) 1997 by John Wiley & Sons, Ltd.