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Biochemical characterization of S-nitrosohemoglobin. Mechanisms underlying synthesis, no release, and biological activity

Biochemical characterization of S-nitrosohemoglobin. Mechanisms underlying synthesis, no release, and biological activity
Biochemical characterization of S-nitrosohemoglobin. Mechanisms underlying synthesis, no release, and biological activity
S-Nitrosohemoglobin (SNO-Hb) has been suggested to act as an endogenous NO donor and physiological regulator of blood pressure. However, the mechanisms responsible for the formation of SNO-Hb and those underlying the release of NO and subsequent biological activity have yet to be elucidated. In the present study, a number of nitrosated oxyhemoglobin (HbO(2)) derivatives have been synthesized and characterized. HbO(2) can be nitrosated at up to three distinct residues, one in the alpha-globin chain and two in the beta-chain. A beta-chain mononitrosated species (designated "SNO-Hb"), generated by the reaction of HbO(2) and S-nitrosoglutathione, released NO via a thiol-dependent mechanism involving nucleophilic attack at the nitrosated thiol functionality of SNO-Hb; in the case of glutathione, this process was associated with the formation of a mixed disulfide. In contrast, multinitrosated hemoglobin species released NO and relaxed vascular smooth muscle by a thiol-independent mechanism. HbO(2) scavenged potently NO released from SNO-Hb and inhibited its vasorelaxant properties. These data show that the predominant vasoactive species released from SNO-Hb is NO, with HNO a putative intermediate; the presence of a low molecular weight thiol is a prerequisite for this process. Such observations have important implications for the generation, metabolic fate, and biological activity of S-nitrosothiols.
0021-9258
28983-28990
Wolzt, Michael
39a59530-4677-4522-89bc-3e05f1f7a37c
MacAllister, Raymond J.
9f4b26b2-72e1-4ccf-9338-362d6193085b
Davis, Dana
3cd21358-ca31-48d4-8c2e-ee7f3b9d82f7
Feelisch, Martin
8c1b9965-8614-4e85-b2c6-458a2e17eafd
Moncada, Salvador
0f661842-cd67-46e6-b82d-47f2c5e0e750
Vallance, Patrick
00f0d09d-9792-4b60-adcd-7c1786c3ffda
Hobbs, Adrian J.
32179ffa-c3c3-4cf8-96bb-58917dc4c8c0
Wolzt, Michael
39a59530-4677-4522-89bc-3e05f1f7a37c
MacAllister, Raymond J.
9f4b26b2-72e1-4ccf-9338-362d6193085b
Davis, Dana
3cd21358-ca31-48d4-8c2e-ee7f3b9d82f7
Feelisch, Martin
8c1b9965-8614-4e85-b2c6-458a2e17eafd
Moncada, Salvador
0f661842-cd67-46e6-b82d-47f2c5e0e750
Vallance, Patrick
00f0d09d-9792-4b60-adcd-7c1786c3ffda
Hobbs, Adrian J.
32179ffa-c3c3-4cf8-96bb-58917dc4c8c0

Wolzt, Michael, MacAllister, Raymond J., Davis, Dana, Feelisch, Martin, Moncada, Salvador, Vallance, Patrick and Hobbs, Adrian J. (1999) Biochemical characterization of S-nitrosohemoglobin. Mechanisms underlying synthesis, no release, and biological activity. The Journal of Biological Chemistry, 274 (41), 28983-28990. (doi:10.1074/jbc.274.41.28983). (PMID:10506146)

Record type: Article

Abstract

S-Nitrosohemoglobin (SNO-Hb) has been suggested to act as an endogenous NO donor and physiological regulator of blood pressure. However, the mechanisms responsible for the formation of SNO-Hb and those underlying the release of NO and subsequent biological activity have yet to be elucidated. In the present study, a number of nitrosated oxyhemoglobin (HbO(2)) derivatives have been synthesized and characterized. HbO(2) can be nitrosated at up to three distinct residues, one in the alpha-globin chain and two in the beta-chain. A beta-chain mononitrosated species (designated "SNO-Hb"), generated by the reaction of HbO(2) and S-nitrosoglutathione, released NO via a thiol-dependent mechanism involving nucleophilic attack at the nitrosated thiol functionality of SNO-Hb; in the case of glutathione, this process was associated with the formation of a mixed disulfide. In contrast, multinitrosated hemoglobin species released NO and relaxed vascular smooth muscle by a thiol-independent mechanism. HbO(2) scavenged potently NO released from SNO-Hb and inhibited its vasorelaxant properties. These data show that the predominant vasoactive species released from SNO-Hb is NO, with HNO a putative intermediate; the presence of a low molecular weight thiol is a prerequisite for this process. Such observations have important implications for the generation, metabolic fate, and biological activity of S-nitrosothiols.

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Published date: 8 October 1999
Organisations: Clinical & Experimental Sciences

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Local EPrints ID: 337880
URI: http://eprints.soton.ac.uk/id/eprint/337880
ISSN: 0021-9258
PURE UUID: 37eb1ee9-249a-4ab3-8e82-7db6574dac72
ORCID for Martin Feelisch: ORCID iD orcid.org/0000-0003-2320-1158

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Date deposited: 29 Jun 2012 11:06
Last modified: 15 Mar 2024 03:41

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Contributors

Author: Michael Wolzt
Author: Raymond J. MacAllister
Author: Dana Davis
Author: Martin Feelisch ORCID iD
Author: Salvador Moncada
Author: Patrick Vallance
Author: Adrian J. Hobbs

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