Shifts in protein charge state distributions with varying redox reagents in nanoelectrospray triple quadrupole mass spectrometry.
The influence of a number of redox reagents on the charge state distribution in nanoelectrospray mass spectrometry was examined using cytochrome c and ubiquitin. The redox active species investigated were: 1,4-benzoquinone, quinhydrone, tetracyanoquinodimethane (TCNQ), hydroquinone, and ascorbic acid. The redox active species was mixed with the protein sample before injection into the nanoelectrospray emitter, and mass spectra were acquired using a triple quadrupole mass spectrometer. Under the same experimental conditions, the charge state distribution of cytochrome c was observed to shift from a weighted average charge state of 14.25 (in the absence of redox species) to 7.10 in the presence of 1,4-benzoquinone. When quinhydrone was mixed with cytochrome c, the charge state distribution of the protein also shifted to lower charge states (weighted average charge state = 9.43), indicative of less charge state reduction for quinhydrone than with 1,4-benzoquinone. Addition of the redox reagent had little effect on the conformation of cytochrome c, as indicated by far ultraviolet circular dichroism spectra. In contrast, the reagents TCNQ, hydroquinone, and ascorbic acid exhibited negligible effects on the observed charge state distribution of the protein. The differing results for these redox reagents can be rationalized in terms of the redox half reactions involving these species. The results observed with ubiquitin upon adding quinhydrone were analogous to those observed with cytochrome c.
Zhao
Cheng
C
Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, USA.
Wood
Troy D
TD
Bruckenstein
Stanley
S
D016227:Benzoquinones; D045304:Cytochromes c / Q000737:chemistry; D006873:Hydroquinones; D007202:Indicators and Reagents; D036103:Nanotechnology; D010084:Oxidation-Reduction; D011506:Proteins / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D025801:Ubiquitin / Q000737:chemistry
D016227:Benzoquinones; D006873:Hydroquinones; D007202:Indicators and Reagents; D011506:Proteins; D025801:Ubiquitin; C004532:quinone; D045304:Cytochromes c; C004601:quinhydrone
Rapid Commun Mass Spectrom. 2001;15(6):451-3
11291125
J Mass Spectrom. 1999 Aug;34(8):787-96
10423559
J Am Soc Mass Spectrom. 1993 Jul;4(7):524-35
24227639
Anal Chem. 1990 Apr 1;62(7):693-8
2327585
Anal Chem. 1994 Jul 1;66(13):2084-7
8067525
Anal Chem. 2003 Dec 15;75(24):6987-94
14670062
Rapid Commun Mass Spectrom. 1997;11(8):875-80
9183856
Anal Chem. 2001 Oct 15;73(20):4836-44
11681459
Anal Chem. 2003 Jul 15;75(14):3660-5
14570224
J Am Soc Mass Spectrom. 1992 Mar;3(3):216-24
24242944
Rapid Commun Mass Spectrom. 1994 May;8(5):394-400
8025335
Anal Chem. 2000 Nov 1;72(21):5158-61
11080858
Chem Rev. 2001 Feb;101(2):269-95
11712248
J Mass Spectrom. 2001 Feb;36(2):124-39
11288194
J Mass Spectrom. 2000 Jul;35(7):784-9
10934432
Chemistry. 2002 Jul 2;8(13):2900-9
12489218
J Mass Spectrom. 2003 Jun;38(6):618-31
12827631
Rapid Commun Mass Spectrom. 1992 Mar;6(3):159-65
1372835
Science. 1999 Jan 8;283(5399):194-7
9880246
Anal Chem. 1994 Sep 15;66(18):2898-904
7978296
Anal Chem. 1993 Jan 1;65(1):1-6
8380538
J Mass Spectrom. 1998 Jul;33(7):664-72
9692249
Anal Chem. 2000 Jan 1;72(1):52-60
10655634
Biochem Biophys Res Commun. 1993 Apr 15;192(1):75-81
8476437
Anal Chem. 1998 Sep 1;70(17):3533-44
9737205
Curr Opin Biotechnol. 2002 Feb;13(1):57-64
11849959
J Am Soc Mass Spectrom. 1993 Jul;4(7):546-56
24227641
Rapid Commun Mass Spectrom. 2001;15(6):401-5
11291117
J Am Soc Mass Spectrom. 1998 Jun;9(6):585-96
9879372
J Am Soc Mass Spectrom. 1992 Sep;3(6):624-30
24234566
Anal Chem. 2001 Dec 15;73(24):6040-6
11791577
Anal Chem. 1991 Sep 15;63(18):1971-8
1661106
Anal Chem. 1990 May 1;62(9):882-99
2194402
J Am Soc Mass Spectrom. 2000 Jul;11(7):659-63
10883822
Science. 1989 Oct 6;246(4926):64-71
2675315