Electrospray ionization mass spectrometric exploration of the high-affinity binding of three natural alkaloids with the mRNA G-quadruplex in the BCL2 5′-untranslated region
Article first published online: 10 JAN 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 27, Issue 4, pages 560–564, 28 February 2013
How to Cite
Tan, W. and Yuan, G. (2013), Electrospray ionization mass spectrometric exploration of the high-affinity binding of three natural alkaloids with the mRNA G-quadruplex in the BCL2 5′-untranslated region. Rapid Commun. Mass Spectrom., 27: 560–564. doi: 10.1002/rcm.6484
- Issue published online: 10 JAN 2013
- Article first published online: 10 JAN 2013
- Manuscript Accepted: 3 DEC 2012
- Manuscript Revised: 27 NOV 2012
- Manuscript Received: 26 OCT 2012
The BCL2 gene encodes an integral outer mitochondrial membrane protein (25 kDa) which regulates the apoptotic death of cells. There is a 25-nucleotide G-rich sequence in the 5'-untranslated region (5'-UTR) of the BCL2 mRNA, which can adopt a G-quadruplex structure. Small molecules which could tightly bind to this structure have a potential function in the regulation of the expression of the BCL2 mRNA.
The 25-mer oligonucleotide (5'-G5CCGUG4UG3AGCUG4-3') was synthesized by TaKaRa Biotechnology Co., Ltd. (TaKaRa, Dalian) with high-performance liquid chromatography (HPLC) purification. Electrospray ionization (ESI) mass spectrometry (MS) was used to probe the binding properties of natural small molecules (P) with the mRNA G-quadruplex in the BCL2 5′-UTR (BCL2Q). Collision-induced dissociation (CID) mass spectrometry and circular dichroism (CD) spectroscopy were performed to evaluate the stabilization of the mRNA G-quadruplex and its complexes.
The results from ESI mass spectra showed that three natural alkaloids (nitidine, palmatine, and jatrorrizine) have high binding affinities to the mRNA G-quadruplex with the binding stoichiometry ranging from 1:1 to 3:1. CID mass spectrometry results revealed that the G-quadruplex-ligand complex lost bases first rather than losing the binding molecules. Increases in the Tm values of the complexes of the G-quadruplex with the natural alkaloids in the CD melting experiments demonstrated that the three small molecules can stabilize the G-quadruplex structure.
Three natural small molecules were found to have very high binding affinities to the mRNA G-quadruplex and stabilize this structure. The properties of these alkaloids revealed promising potentials to regulate the expression of the BCL2 protein from the posttranscriptional pathway. Copyright © 2013 John Wiley & Sons, Ltd.