Identification of Anti-Long Chain Saturated Fatty Acid IgG Antibodies in Serum of Patients with Type 2 Diabetes

Figure 2

Patient serum reacts with palmitoylated BSA. (a) Diagram of BSA palmitoylation sites. Seven accessible hydroxyl groups that can be palmitoylated are present on serine, tyrosine, or threonine of BSA. (b) ELISA identification of BSA-PA reactive IgG antibodies. En Balance baseline serum samples from Hispanic diabetic patients were tested by ELISA for IgG Abs that react with BSA (2/36) or BSA-PA (36/36). The cut-off value for positive antibody reactivity against BSA-PA (>0.186) was defined as an absorbance greater than two standard deviations above the mean value for BSA. (c) A Coomassie stained gel of palmitoylated BSA (BSA-PA). Palmitoylated BSA migrates faster on the gel than BSA due to an increased (−) charge contributed by SDS association with the palmitoyl groups. (d) Western blot can detect differential levels of Ab that react with BSA-PA. Western blots with BSA alone (10 μg) and BSA-PA (60 μg) were probed with total serum from Hispanics with type 2 diabetes which had a high OD₄₅₀ () or low OD₄₅₀ () as determined by ELISA for reactivity with BSA-PA. Anti-human IgG was the secondary antibody. (c) Statistical analysis was accomplished with a Wilcoxon-ranked sign test. .

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