Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006 Feb 8;128(5):1422-3.
doi: 10.1021/ja057097f.

Thionitroxides, RSNHO*: the structure of the SNO moiety in "S-Nitrosohemoglobin", a possible NO reservoir and transporter

Yi-Lei Zhao  1 , K N Houk
Affiliations

Thionitroxides, RSNHO*: the structure of the SNO moiety in "S-Nitrosohemoglobin", a possible NO reservoir and transporter

Yi-Lei Zhao et al. J Am Chem Soc. .

Abstract

Nitric oxide (NO) plays important roles in many biological processes. S-Nitrosothiols have long been believed to have significant roles in NO biochemistry. The modified cysteine residue of hemoglobin was previously identified as a distorted S-nitrosothiol (RSNO) or an S-hydroxyamino radical (RSN*OH). Here we show that a thionitroxide (RSNHO*, S-aminyloxyl radical) is likely the observed species. Computational studies show that the thionitroxide is the only structure consistent with the electron density in the hemoglobin Cysbeta93-SNO structure previously reported. Although a metastable adduct, the thionitroxide in a hydrogen-bonding environment can form readily and release NO upon exposure to an aqueous environment. The thionitroxides could be responsible for the biological effects attributed to S-nitrosothiols or could serve as precursors to S-nitrosothiols in oxidative conditions.

PubMed Disclaimer

Figures

Figure 1
Figure 1
The crystallographic C-S-N-O structures in purported S-nitroso-hemoglobin (distances in angstrom, unexpected dihedral angles in red).
Figure 2
Figure 2
Rotational energy profiles of RSNO, RS-NH-O·, RS-N·-OH, and RS-NH-OH (R = Me) with the B3LYP/6-31+G* method (two dashed lines stand for the dihedral angles of the observed SNO species in the proteins), and the CBS-QB3 calculated global minima of cis-RSNO (1), trans-RSNO (2), RS-N·-OH (3), RS-NH-O· (4), and RS-NH-OH (5), and rotational transition states for RSNO (6≠) and RS-N·-OH (7≠).
See this image and copyright information in PMC

References

    1. Jia L, Bonaventura C, Bonaventura J, Stamler JS. Nature. 1996;380:221–226. - PubMed
    2. Stamler JS, Jia L, Eu JP, McMahon TJ, Demchenko IT, Bonaventura J, Gernert K, Piantadosi CA. Science. 1997;276:2034–2037. - PubMed
    3. Gow AJ, Stamler JS. Nature. 1998;391:169–173. - PubMed
    4. Minning DM, Gow AJ, Bonaventura J, Braun R, Dewhirst M, Goldberg DE, Stamler JS. Nature. 1999;401:497–502. and references therein. - PubMed
    1. Fukuto JM, Cho JY, Switzer CH. In: Nitric Oxide Biology and Pathobiology. Ignarro LJ, editor. Academic; 2000. pp. 23–40.
    1. Zhang YH, Hogg N. PNAS. 2004;101:7891–7896. and references therein. - PMC - PubMed
    2. Luchsinger BP, Rich EN, Gow AJ, Williams EM, Stamler JS, Singel DJ. PNAS. 2003;100:461–466. - PMC - PubMed
    3. Pezacki JP, Ship NJ, Kluger R. J. Am. Chem.Soc. 2001;123:4615–4616. - PubMed
    1. Chan NL, Rogers PH, Arnone A. Biochemistry. 1998;37:16459–16464. - PubMed
    2. Chan NL, Kavanaugh JS, Rogers PH, Arnone A. Biochemistry. 2004;43:118–132. - PubMed
    1. Field L, Dilts RV, Ravichandran R, Lenhert PG, Carnahan GE. Chem. Comm. 1978:249–250.
    2. Arulsamy N, Bohle DS, Butt JA, Irvine GJ, Jordan PA, Sagan E. J. Am. Chem. Soc. 1999;121:7115–7123.
    3. Carnahan GE, Lenhert PG, Ravichandran R. Acta Cryst. B. 1978;34:2645–2648.
    4. Lee J, Yi GB, Powell DR, Khan MA, Richter-Addo GB. Canadian Journal of Chemistry. 2001;79:830–840.

Publication types