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Exploration of binding affinity and selectivity of brucine with G‐quadruplex in the c‐myb proto‐oncogene by electrospray ionization mass spectrometry
Author(s) -
Li Huihui,
Hai Jinhui,
Zhou Jiang,
Yuan Gu
Publication year - 2015
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7454
Subject(s) - chemistry , myb , g quadruplex , electrospray ionization , dna , mass spectrometry , brucine , gene , microbiology and biotechnology , biochemistry , gene expression , chromatography , biology , strychnine
Rationale The c‐myb gene is a potential therapeutic target for human tumors and leukemias. Active ingredients from natural products may be used as drugs in chemotherapy for human cancers. Here, electrospray ionization mass spectrometry (ESI‐MS) was used to probe the formation and recognition of the G‐quadruplex structure from the G‐rich sequence that is found in the c‐myb gene promoter, 5'‐GGGCTGGGCTGGGCGGGG‐3'. The aim of our study is to evaluate a potential binder for the c‐myb gene from natural products, and thereby to modulate c‐myb gene expression. Methods ESI‐MS, as an effective method, was utilized not only to characterize the formation of the G‐quadruplex in the c‐myb oncogene, but also as a tool to probe the binding characteristics of alkaloid molecules with the target G‐quadruplex DNA. Results ESI‐MS results with the support of circular dichroism (CD) spectra demonstrated the formation of an intramolecular parallel‐stranded G‐quadruplex in the c‐myb oncogene promoter. A screening of six alkaloid molecules showed that brucine ( P1 ) had a strong binding affinity to the c‐myb G‐quadruplex DNA. It is notable that P1 can bind selectively to the c‐myb G‐quadruplex with respect to duplex DNAs, as well as to G‐quadruplexes in other types of gene sequences. According to ESI‐MS results, in which the stability was tested by capillary heating and collision‐induced dissociation, the binding of P1 could thermally stabilize the c‐myb G‐quadruplex DNA. Conclusions In this work, brucine ( P1 ), an alkaloid molecule, has been found to bind to the intramolecular parallel G‐quadruplex in the c‐myb oncogene promoter with high affinity and selectivity, and could thermally stabilize the c‐myb G‐quadruplex DNA, indicating that the binding of P1 has the potential to modulate c‐myb gene expression. Copyright © 2015 John Wiley & Sons, Ltd.