Journal: PLoS ONE
Article Title: Post-Streptococcal Auto-Antibodies Inhibit Protein Disulfide Isomerase and Are Associated with Insulin Resistance
Figure Lengend Snippet: Functional effect of anti-PDI antibodies on PDI activity and association of anti-PDI status with insulin resistance. ( A ) Effects of purified anti-PDI antibodies on purified bovine PDI activity. Purified Bovine PDI activity was measured in the presence of 0–60 µg/ml purified anti- bovine PDI from anti-PDI positive subjects (triangles) and 0–160 µg/ml total IgG from rabbit immuned against bovine PDI (diamonds). Pooled human and rabbit IgG (dashed lines) were used as control. Results are compared to activity in the presence of same volume of PBS (defined as 100%) and presented as a mean ± SEM of three experiments. PDI activity was measured using the insulin transhydrogenase assay. ( B ) Effects of human sera (1∶50) on human recombinant PDI activity. Recombinant human PDI activity was measured in the presence of 20 µl/ml human sera positive or negative for anti-human PDI antibody. Results are presented as mean ± SEM. ( C ) Association of anti- human PDI status with serum insulin levels. Results are presented as mean ± SEM, adjusted for age, gender, education, BMI and smoking. ( D ) Association of anti-human PDI status with insulin resistance. Insulin resistance was estimated using HOMA (Homeostatic Model Assessment of insulin resistance). Results are presented as mean ± SEM, adjusted for age, gender, education, BMI and smoking. For details, see Table S2 .
Article Snippet: Antibodies: Rabbit polyclonal anti-bovine PDI, human IgG, and rabbit IgG from Sigma-Aldrich; Donkey anti-human IgG conjugated with horseradish peroxidase - from Jackson ImmunoResearch Laboratories.
Techniques: Functional Assay, Activity Assay, Purification, Recombinant