Improved resolution of the human adipose tissue proteome at alkaline and wide range pH by the addition of hydroxyethyl disulfide

Polycystic ovary syndrome is a very common disease affecting 6.5% of women. It is frequently associated with obesity with the link between the two disorders being insulin resistance. From morbidly obese women submitted to surgical treatment of obesity, we obtain intra-abdominal adipose tissue samples in order to compare protein patterns between women with and without polycystic ovary syndrome by two-dimensional gel electrophoresis (2-DE) analysis. Adipose tissue is a complex material extremely rich in lipids. To improve protein solubilization a lysis buffer containing 8.4 M urea, 2.4 M thiourea, 5% 3-((3-cholamidoproyl)dimethyl-amino)-1-propanesulfonate and 50 mM dithiothreitol was used and samples were centrifuged to remove fat. Hydroxyethyl disulfide was added to increase resolution in the alkaline region (Olsson, I., Larsson, K., Palmgren, R., Bjellqvist, B., Proteomics 2002, 2, 1630-1632) and it also improved resolution in a wide pH range (3-10). Our work shows for the first time 2-DE maps of human adipose tissue and identifies some of the proteins by mass spectrometry. This information will aid studies on metabolic diseases such as polycystic ovary syndrome, obesity, hypertension and type 2 diabetes.