Ming Luo1, Ariane Boudier1, Arnaud Pallotta1, Philippe Maincent1, Jean-Baptiste Vincourt2,3, Pierre Leroy1. 1. a Université De Lorraine - CITHEFOR EA 3452 , Nancy Cedex , France ; 2. b Université De Lorraine - IMoPA, UMR 7365 CNRS , Vandœuvre-lès-Nancy Cedex , France ; 3. c Proteomics Platform of Fédération De Recherche 3209 , Biopole De La Faculté De Médecine De Nancy , Vandœuvre-lès-Nancy Cedex , France.
Abstract
BACKGROUND: Nitric oxide (NO) is a gaseous transmitter playing numerous physiological roles and characterized by a short half-life. Its binding to endogenous thiols increases its stability, facilitating its storage and transport. The purpose of this study was to investigate the nitrosated serum albumin (SA-SNO) and to provide a reference for its easy preparation for further use in in vitro studies. METHODS: Serum albumin (SA) was S-nitrosated by reacting with (i) NaNO2 in acidic medium; (ii) different low-molecular weight S-nitrosothiols (RSNO) (S-nitrosocysteine (CysNO), S-nitrosoglutathione (GSNO), and S,S'-dinitrosobucillamine (Buc(NO)2)); and (iii) diethylamine NONOate (DEA/NO). SA-SNO was purified by size exclusion chromatography and the S-nitrosation site and the rate were studied by mass spectrometry and Griess-Saville assay, respectively. Then, SA-SNO was characterized by spectrofluorimetry, dynamic light scattering, and circular dichroism. Finally, SA-SNO reactivity with citrate stabilized gold nanoparticles (AuNP-citrate) was investigated via determination of NO release. RESULTS: S-nitrosation rates of SA were 90.1 ± 3.3, 76.8 ± 2.7, 80.3 ± 3.2, 84.8 ± 5.0, and 15.4 ± 1.9% (n = 5), when SA was reacted with acidified NaNO2, CysNO, GSNO, Buc(NO)2, and DEA/NO, respectively. The physicochemical characterization indicated that the resulting product corresponded to a mono-S-nitrosothiol (on cysteine-34), and the conformational construction remained unchanged. Stability studies showed that the NO content was preserved over 1 week. AuNP-citrate reacted with SA-SNO with increase of its hydrodynamic diameter but preservation of SNO bond. CONCLUSIONS: SA-SNO prepared and stored under the reported conditions affords a well-defined reference suitable for in vitro studies.
BACKGROUND:Nitric oxide (NO) is a gaseous transmitter playing numerous physiological roles and characterized by a short half-life. Its binding to endogenous thiols increases its stability, facilitating its storage and transport. The purpose of this study was to investigate the nitrosated serum albumin (SA-SNO) and to provide a reference for its easy preparation for further use in in vitro studies. METHODS:Serum albumin (SA) was S-nitrosated by reacting with (i) NaNO2 in acidic medium; (ii) different low-molecular weight S-nitrosothiols (RSNO) (S-nitrosocysteine (CysNO), S-nitrosoglutathione (GSNO), and S,S'-dinitrosobucillamine (Buc(NO)2)); and (iii) diethylamine NONOate (DEA/NO). SA-SNO was purified by size exclusion chromatography and the S-nitrosation site and the rate were studied by mass spectrometry and Griess-Saville assay, respectively. Then, SA-SNO was characterized by spectrofluorimetry, dynamic light scattering, and circular dichroism. Finally, SA-SNO reactivity with citrate stabilized gold nanoparticles (AuNP-citrate) was investigated via determination of NO release. RESULTS: S-nitrosation rates of SA were 90.1 ± 3.3, 76.8 ± 2.7, 80.3 ± 3.2, 84.8 ± 5.0, and 15.4 ± 1.9% (n = 5), when SA was reacted with acidified NaNO2, CysNO, GSNO, Buc(NO)2, and DEA/NO, respectively. The physicochemical characterization indicated that the resulting product corresponded to a mono-S-nitrosothiol (on cysteine-34), and the conformational construction remained unchanged. Stability studies showed that the NO content was preserved over 1 week. AuNP-citrate reacted with SA-SNO with increase of its hydrodynamic diameter but preservation of SNO bond. CONCLUSIONS:SA-SNO prepared and stored under the reported conditions affords a well-defined reference suitable for in vitro studies.