Development analytical methodology and characterization of circulating albumin microheterogeneity in patients with acute alcohol intoxication by mass spectrometry micro q-tof and maldi-tof

The Human Serum Albumin (HSA) is one of the most studied human proteins, and its different and multiple functions have attracted and continue to attract the interest of researchers. HSA presents biological properties, such as antioxidant and scavenging activities, binding and transport of many endogenous and exogenous substances, and endothelial regulation function. The aim of the present work was to investigate how an even exacerbated oxidative stress condition may affect HSA structure. In particular, a study on a population of patient affected by alcoholic liver disease (ALD) was performed. Oxidative stress, indeed, has been detected in most all clinical and experimental conditions of ALD. The optimized methodology was applied for a preliminary screening of HSA isoforms derived from the plasma of 10 alcoholic patients with diagnosis of cirrhosis and from 10 healthy volunteers. From the data obtained, a drastic change in HSA structure is immediately evident. First of all, the relative percentage of the native, unmodified serum albumin is dramatically reduced. Comparing this result with related works in a study on the characterization of HSA in patients affected by cirrhosis, it can be observed that in the case of cirrhosis the relative amount of native HSA decreased of 7-9% while in ALD patients the decrease was attested around 22%. This effect may be attributed to the oxidative stress conditions which lead to both the formation of new disulfide bridges with free cysteines residues and to the oxidation of HSA cysteine and methionine residues. This hypothesis is supported by the sharp increase oh the cysteinilated and oxidized isoforms.