Mouse Anti-LEP Recombinant Antibody (clone 9F8) (CAT#: PABL-259)

Figure 1 Competitive binding of leptin and 9F8 to ObR. The binding of leptin-biotin to the full-length extracellular domain of ObR was measured in the presence of either 9F8 mAb or unlabeled leptin. The IC50 for leptin and 9F8 mAb binding to ObR are approximately 0.76 nM and 1.0 nM, respectively.

Carpenter, B., Hemsworth, G. R., Wu, Z., Maamra, M., Strasburger, C. J., Ross, R. J., & Artymiuk, P. J. (2012). Structure of the human obesity receptor leptin-binding domain reveals the mechanism of leptin antagonism by a monoclonal antibody. Structure, 20(3), 487-497.

Figure 2 The affinity of leptin binding to recombinant LBD was calculated by competitive binding assay (data shown represent the mean of three independent experiments, and error bars indicate the standard deviation between data sets). The IC50 of leptin binding to LBD is 0.78 ± 0.05 nM (SD).

Carpenter, B., Hemsworth, G. R., Wu, Z., Maamra, M., Strasburger, C. J., Ross, R. J., & Artymiuk, P. J. (2012). Structure of the human obesity receptor leptin-binding domain reveals the mechanism of leptin antagonism by a monoclonal antibody. Structure, 20(3), 487-497.

Figure 3 Gel filtration analysis of leptin and 9F8 Fab binding to LBD.

Leptin, LBD, and 9F8 Fab each resolve as a single predominant peak with retention volumes of 16.72, 15.94, and 14.95 ml, respectively (peaks shown in parentheses represent contaminants in the protein preparations). 1:1 molar ratio mixtures of LBD/leptin and LBD/9F8 Fab resolve with retention volumes of 15.32 and 13.99 ml, respectively. A 1:1:1 molar ratio mixture of all three proteins resolves as a predominant peak with a retention volume of 14.04 ml, which relates well to the LBD-9F8 Fab complex (13.99 ml). The shoulder peak (approximately 15.35 ml) is likely to contain both free 9F8 Fab (14.95 ml) and the LBD-leptin complex (15.32 ml). Significantly, no peak with a retention volume lower than 14.04 ml was present, demonstrating that leptin and 9F8 Fab cannot simultaneously bind to LBD.

Carpenter, B., Hemsworth, G. R., Wu, Z., Maamra, M., Strasburger, C. J., Ross, R. J., & Artymiuk, P. J. (2012). Structure of the human obesity receptor leptin-binding domain reveals the mechanism of leptin antagonism by a monoclonal antibody. Structure, 20(3), 487-497.

Figure 4 The mAb 2H6 or mAb 9F8, respectively, were immobilized on microtiter plates.

Binding of the biotinylated soluble leptin receptor to mAb 9F can be displaced by leptin, whereas binding to mAb 2H6 is independent from leptin. Antisoluble leptin receptor mAb 2H6 binds to a protein in human serum, which is able to bind biotinylated leptin. The binding of this soluble receptor to biotinylated human leptin is displaceable by nonlabeled human, mouse, and rat leptin but not by nonlabeled hGH or IL-6.

Wu, Z., Bidlingmaier, M., Liu, C., De Souza, E. B., Tschöp, M., Morrison, K. M., & Strasburger, C. J. (2002). Quantification of the soluble leptin receptor in human blood by ligand-mediated immunofunctional assay. The Journal of Clinical Endocrinology & Metabolism, 87(6), 2931-2939.