Nano Archive

Structural Characterization of G-Quadruplexes in Deoxyguanosine Clusters Using Ion Mobility Mass Spectrometry

Baker, Erin Shammel and Bernstein, Summer L. and Bowers, Michael T. (2005) Structural Characterization of G-Quadruplexes in Deoxyguanosine Clusters Using Ion Mobility Mass Spectrometry. Journal of the American Society for Mass Spectrometry, 16 (7). 989 - 997.

Full text is not hosted in this archive but may be available via the Official URL, or by requesting a copy from the corresponding author.

Official URL: http://www.sciencedirect.com/science/article/B6TH2...

Abstract

The aggregation and conformation of deoxyguanosine (dG) in an ammonium acetate buffer solution were examined using mass spectrometry, ion mobility, and molecular mechanics/dynamics calculations. The nano-ESI mass spectrum indicated that 4 and 6 dGs cluster with 1 NH4+; 11 dGs with 2 NH4+; 14, 16, and 17 dGs with 3 NH4+; and 23 dGs with 4 NH4+. The collision cross sections with helium were measured and compared with calculated cross sections of theoretical structures generated by molecular mechanics/dynamics calculations. Three distinct arrival time distribution (ATD) peaks were observed for (4dG + NH4)+. One peak was assigned to the quadruplex structure of (4dG + NH4)+, while the other two peaks corresponded to the quadruplex structures of (8dG + 2NH4)2+ and (12dG + 3NH4)3+, all with the same m/z. Four ATD peaks were observed for (6dG + NH4)+ and assigned to the globular structure of (6dG + NH4)+, and the quadruplex structures of (12dG + 2NH4)2+, (18dG + 3NH4)3+, and (24dG + 4NH4)4+. Two ATD peaks were observed for (11dG + 2NH4)2+ and assigned to the quadruplex structures of (11dG + 2NH4)2+ and (22dG + 4NH4)4+. All of the other clusters in the mass spectrum (14, 16, and 17 dGs with 3 NH4+ and 23 dGs with 4 NH4+) only had one peak in their ATDs and in all cases the theoretical structures in a quadruplex arrangement agreed with the experimental cross sections. These results provide compelling evidence that quadruplexes are present in solution and retain their structure during the spray process, dehydration, and detection.

Item Type:Article
Subjects:Material Science > Nanofabrication processes and tools
Biomedical Science > Nanomedicine
ID Code:5819
Deposited By:SPI
Deposited On:07 Jul 2009 16:53
Last Modified:07 Jul 2009 16:53

Repository Staff Only: item control page