Charge loss in gas-phase multiply negatively charged oligonucleotides

Journal of Physical Chemistry A

Volumn 109, Issue 1, 2005, Pages 240-249

  Anusiewicz, Iwona ^a,b   Berdys Kochanska, Joanna ^a,b   Czaplewski, Cezary ^b   Sobczyk, Monika ^a,b   Daranowski, Emma M ^b,c   Skurski, Piotr ^a,b   Simons, Jack ^a  

^a UNIVERSITY OF UTAH   (United States)

^b UNIVERSITY OF GDA SK   (Poland)

^c UNIVERSITY OF COLORADO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ELECTRON LOSS; OLIGONUCLEOTIDES; PHOSPHATE SITES; TUNNELING RATE;

ACTIVATION ENERGY; BINDING ENERGY; ELECTRON TUNNELING; NEGATIVE IONS; REDUCTION; TEMPERATURE MEASUREMENT;

GASES;

ION; OLIGONUCLEOTIDE; PHOSPHATE;

CHEMICAL STRUCTURE; CHEMISTRY; COMPUTER SIMULATION; CONFORMATION; ELECTRON; REVIEW; TEMPERATURE;

COMPUTER SIMULATION; ELECTRONS; IONS; MODELS, MOLECULAR; NUCLEIC ACID CONFORMATION; OLIGONUCLEOTIDES; PHOSPHATES; TEMPERATURE;

EID: 12344310341     PISSN: 10895639     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp046913n     Document Type: Review

References (8)

1. Danell, A. S.; Parks, J. H. J. Am. Soc. Mass Spectrum. 2003, 14, 1330-1339.
2. These species consist of DNA bases connected to deoxyribose groups which, in turn, are bonded to phosphate groups. The ions are introduced into the gas phase by spraying samples that, in their liquid phase, likely have all of the phosphate groups negatively charged. However, once in the gas phase, the sample loses electrons (probably from one or more of the phosphate groups) to produce an anion of lower overall charge than the number of phosphate units it contains.
3. The charge loss has been determined to arise from electron ejection rather than molecular fragmentation because the charge-to-mass ratio of the ions produced when the charge is lowered is consistent with no mass loss.
4. Fluorescent labels are used to introduce excess energy into the gas-phase ions in some of the Parks experiments. However, the charge-loss phenomenon that we deal with in this paper occurs with or without the label.
5. Simons, J.; Skurski, P.; Barrios, R. J. Am. Chem. Soc. 2000, 122, 11893-11899.
6. Case, D. A.; Pearlman, D. A.; Caldwell, J. W.; Cheatham, T. E., III; Wang, J.; Ross, W. S.; Simmerling, C. L.; Darden, T. A.; Merz, K. M.; Stanton, R. V.; Cheng, A. L.; Vincent, J. J.; Crowley, M.; Tsui, V.; Gohlke, H.; Radmer, R. J.; Duan, Y.; Pitera, J.; Massova, I.; Seibel, G. L.; Singh, U. C.; Weiner, P. K.; Kollman, P. A. AMBER 7, University of California, San Francisco, 2002.
7. Boyly, C. I.; Cieplak, P.; Cornell, W. D.; Kollman, P. A. J. Phys. Chem. 1993, 97, 10269-10280.
8. Two phosphate units that are nearest neighbors have most-probable distances of approximately 4 Å (and can fluctuate to even closer distances) and thus produce Coulomb repulsions of 14.4/4 = 3.6 eV. When the Coulomb interactions of any other negative sites are added to this, the total potential easily exceeds 5.1 eV.