The purpose of the present study was to determine the relative amount of S-thiolated proteins (i.e. S-homocysteinylated, S-cysteinylglycinylated, S-glutathionylated and S-cysteinylated proteins) to the total protein thiols (i.e. the sum of reduced protein sulphydryl groups (PSHs) and protein mixed disulphides with homocysteine [HcySH], cysteinylglycine, cysteine [CysSH] and glutathione) in the plasma of healthy individuals aged 20 to 93. After plasma separation, total protein thiols, S-thiolated proteins, as well as CysSH, cystine, HcySH and homocystine were measured by high-performance liquid chromatography (HPLC) with fluorescence determination of the thiol-monobromobimane conjugate. Determination of plasma levels of protein thiols was performed by spectrophotometry with 5,5′-dithiobis(2-nitrobenzoic acid) as a titrating agent. The present study demonstrates an age-dependent reduction in the amount of PSHs, and an age-dependent increase in cysteinylated and homocysteinylated plasma proteins in healthy human beings. This indicates that the efficiency of the reduced protein thiol pool as an antioxidant defence system decreases with age, possibly causing an increased risk of irreversible oxidation (i.e. further oxidation to sulphinic and sulphonic acids, which are usually not reducible by thiol reducing agents) of sulphydryl groups of plasma proteins. The drop in the plasma level of protein sulphydryl groups suggests depletion and/or impairment of the antioxidant capacity of plasma, likely related to an alteration of the delicate balance between the different redox forms of thiols.

Rossi, R., Giustarini, D., Milzani, A., & DALLE DONNE, I. (2009). Cysteinylation and homocysteinylation of plasma protein thiols during ageing of healthy human beings. JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, 13(9B), 3131-3140 [10.1111/j.1582-4934.2008.00417.x].

Cysteinylation and homocysteinylation of plasma protein thiols during ageing of healthy human beings

ROSSI, RANIERI;GIUSTARINI D;
2009

Abstract

The purpose of the present study was to determine the relative amount of S-thiolated proteins (i.e. S-homocysteinylated, S-cysteinylglycinylated, S-glutathionylated and S-cysteinylated proteins) to the total protein thiols (i.e. the sum of reduced protein sulphydryl groups (PSHs) and protein mixed disulphides with homocysteine [HcySH], cysteinylglycine, cysteine [CysSH] and glutathione) in the plasma of healthy individuals aged 20 to 93. After plasma separation, total protein thiols, S-thiolated proteins, as well as CysSH, cystine, HcySH and homocystine were measured by high-performance liquid chromatography (HPLC) with fluorescence determination of the thiol-monobromobimane conjugate. Determination of plasma levels of protein thiols was performed by spectrophotometry with 5,5′-dithiobis(2-nitrobenzoic acid) as a titrating agent. The present study demonstrates an age-dependent reduction in the amount of PSHs, and an age-dependent increase in cysteinylated and homocysteinylated plasma proteins in healthy human beings. This indicates that the efficiency of the reduced protein thiol pool as an antioxidant defence system decreases with age, possibly causing an increased risk of irreversible oxidation (i.e. further oxidation to sulphinic and sulphonic acids, which are usually not reducible by thiol reducing agents) of sulphydryl groups of plasma proteins. The drop in the plasma level of protein sulphydryl groups suggests depletion and/or impairment of the antioxidant capacity of plasma, likely related to an alteration of the delicate balance between the different redox forms of thiols.
Rossi, R., Giustarini, D., Milzani, A., & DALLE DONNE, I. (2009). Cysteinylation and homocysteinylation of plasma protein thiols during ageing of healthy human beings. JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, 13(9B), 3131-3140 [10.1111/j.1582-4934.2008.00417.x].
File in questo prodotto:
File Dimensione Formato  
2009 Rossi JCMM.pdf

accesso aperto

Tipologia: PDF editoriale
Licenza: Creative commons
Dimensione 916.21 kB
Formato Adobe PDF
916.21 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/411741