Like polarity ion/ion reactions enable the investigation of specific metal interactions in nucleic acids and their noncovalent assemblies.
A rare example of ion/ion reaction between species of like polarity was shown to take place during the transfer of metal cations from nucleic acid substrates to chelating agents in the gas phase. Gaseous anionic reactants were generated from separate solutions of analyte and chelator by using a dual nanospray setup. The respective multiply charged ions shared the same path and were allowed to react for a predetermined interval in an rf-only hexapole before high-resolution analysis by Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Efficient transfer of sodium and magnesium ions was readily observed with significant reduction of the nonspecific adducts that are typically associated with decreased sensitivity and resolution in the analysis of nucleic acid samples. Metal cations were abstracted from the initial analyte without being replaced by protons, in a process that was clearly dependent on the concentration of chelator in the auxiliary emitter and on the time spent by the reactants in the hexapole element. A survey of the properties of selected anionic chelators showed that their known affinity for a target cation in solution was more critical than their maximum anionic charge in determining the outcome of the transfer process. The analysis of selected assemblies requiring divalent cations to preserve their structural integrity and functional properties demonstrated that ion/ion reactions were clearly capable of discriminating between nonspecific interactions and specific coordination based on transfer susceptibility. These examples demonstrated that the ability to selectively eliminate nonspecific adducts in the gas phase, after the desolvation process is complete, offers a unique opportunity for studying specific metal binding in biological systems without resorting to separation procedures that may adversely affect the position of binding equilibria in solution and disrupt the assemblies under investigation.
Turner
Kevin B
KB
Department of Chemistry and Biochemistry, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21228, USA.
Monti
Sarah A
SA
Fabris
Daniele
D
D002614:Chelating Agents / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D008024:Ligands; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D009696:Nucleic Acids / Q000737:chemistry*; D044367:Phase Transition; D017550:Spectroscopy, Fourier Transform Infrared
D002614:Chelating Agents; D005740:Gases; D007477:Ions; D008024:Ligands; D008670:Metals; D009696:Nucleic Acids
Nucleic Acids Res. 2006 Mar 06;34(5):1305-16
16522643
Mass Spectrom Rev. 1996;15(2):67-138
27082318
J Mol Biol. 2007 Jan 12;365(2):396-410
17070549
Anal Chem. 2007 Oct 15;79(20):7916-9
17867655
J Am Soc Mass Spectrom. 1995 Jan;6(1):27-39
24222058
Science. 1996 Sep 20;273(5282):1678-85
8781224
Curr Opin Struct Biol. 2003 Jun;13(3):325-33
12831883
RNA. 2004 Mar;10(3):335-43
14970378
Nucleic Acids Res. 2001 Nov 1;29(21):E103-3
11691940
RNA. 2004 Sep;10(9):1366-79
15317974
Rapid Commun Mass Spectrom. 1999;13(10):954-62
10353227
Protein Sci. 1992 May;1(5):563-74
1304355
J Am Soc Mass Spectrom. 1996 Aug;7(8):697-706
24203563
Proc Natl Acad Sci U S A. 1995 Mar 14;92(6):2318-22
7534419
Mass Spectrom Rev. 2005 Nov-Dec;24(6):931-58
15706594
Rapid Commun Mass Spectrom. 1994 May;8(5):394-400
8025335
Rapid Commun Mass Spectrom. 1992 Mar;6(3):159-65
1372835
J Am Soc Mass Spectrom. 1996 Sep;7(9):923-9
24203606
J Mol Biol. 2003 May 30;329(2):229-38
12758072
J Membr Biol. 2004 Jun 1;199(3):163-71
15457373
J Am Soc Mass Spectrom. 2001 Jul;12(7):780-5
11444599
Anal Chem. 1996 Sep 15;68(18):3295-9
8797389
J Am Soc Mass Spectrom. 2005 Nov;16(11):1750-6
16182558
Rapid Commun Mass Spectrom. 1992 Dec;6(12):771-6
1283705
J Mol Biol. 1997 Nov 14;273(5):1020-31
9367788
Annu Rev Biochem. 1967;36:407-48
18257727
Nucleic Acids Res. 1993 Jul 11;21(14):3191-6
8341593
Anal Chem. 1998 Sep 1;70(17):3553-6
9737206
Proc Natl Acad Sci U S A. 1993 Feb 1;90(3):790-3
8381533
J Phys Chem A. 2005 Apr 28;109(16):3608-16
16568152
J Am Soc Mass Spectrom. 2004 Apr;15(4):607-15
15047065
Biochemistry. 1995 Jan 31;34(4):1376-85
7827085
Anal Chem. 1996 Nov 15;68(22):4026-32
8916454
Anal Chem. 1996 Jan 1;68(1):1-8
8779426
Biophys J. 1993 Nov;65(5):1916-28
8298021
Cell. 1999 May 14;97(4):491-502
10338213
Rapid Commun Mass Spectrom. 1998;12(23):1957-61
9842743
Annu Rev Phys Chem. 1999;50:517-36
10575730
Nat Biotechnol. 1997 May;15(5):427-31
9131619
J Am Soc Mass Spectrom. 1992 Sep;3(6):624-30
24234566
J Mol Biol. 2002 May 10;318(4):963-73
12054794
Nat Rev Mol Cell Biol. 2005 May;6(5):399-412
15956979
J Am Chem Soc. 2003 Oct 15;125(41):12404-5
14531672
Proc Natl Acad Sci U S A. 1997 Apr 29;94(9):4262-6
9113977
Science. 1993 Aug 6;261(5122):709-14
7688142
J Mol Biol. 2007 Jun 8;369(3):812-28
17466332
Mass Spectrom Rev. 1998 Nov-Dec;17(6):369-407
10360331
J Am Chem Soc. 2003 Jun 18;125(24):7238-49
12797797
J Mol Biol. 1990 Dec 5;216(3):689-99
2124274
J Mass Spectrom. 2000 Jul;35(7):784-9
10934432
Biochemistry. 2003 Sep 16;42(36):10736-45
12962498