May 1, 2022

An anti-ANGPTL3/8 antibody decreases circulating triglycerides by binding to a LPL-inhibitory leucine zipper-like motif

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Data from this study reveals that a novel epitope forms when ANGPTL8 combines with ANGPTL3 to create the ANGPTL3/8 complex. This novel conformational epitope includes N-terminal regions of both proteins that are involved in the inhibition of LPL activity.

Triglycerides (TG) are required for fatty acid transport and storage and are essential for human health. Angiopoietin-like-protein 8 (ANGPTL8) has previously been shown to form a complex with ANGPTL3 that increases circulating TG by potently inhibiting LPL. We also recently showed that the TG-lowering apolipoprotein A5 (ApoA5) decreases TG levels by suppressing ANGPTL3/8-mediated LPL inhibition. To understand how LPL binds ANGPTL3/8 and ApoA5 blocks this interaction, we used hydrogen-deuterium exchange mass-spectrometry and molecular modeling to map binding sites of LPL and ApoA5 on ANGPTL3/8. Remarkably, we found that LPL and ApoA5 both bound a unique ANGPTL3/8 epitope consisting of N-terminal regions of ANGPTL3 and ANGPTL8 that are unmasked upon formation of the ANGPTL3/8 complex. We further used ANGPTL3/8 as an immunogen to develop an antibody targeting this same epitope. After refocusing on antibodies that bound ANGPTL3/8, as opposed to ANGPTL3 or ANGPTL8 alone, we utilized bio-layer interferometry to select an antibody exhibiting high-affinity binding to the desired epitope. We revealed an ANGPTL3/8 leucine zipper-like motif within the anti-ANGPTL3/8 epitope, the LPL-inhibitory region, and the ApoA5-interacting region, suggesting the mechanism by which ApoA5 lowers TG is via competition with LPL for the same ANGPTL3/8-binding site. Supporting this hypothesis, we demonstrate that the anti-ANGPTL3/8 antibody potently blocked ANGPTL3/8-mediated LPL inhibition in vitro and dramatically lowered TG levels in vivo. Together, these data show that an anti-ANGPTL3/8 antibody targeting the same leucine zipper-containing epitope recognized by LPL and ApoA5 markedly decreases TG by suppressing ANGPTL3/8-mediated LPL inhibition.


Balasubramaniam, D., Schroeder, O., Russell, A. M., Fitchett, J. R., Austin, A. K., Beyer, T. P., Chen, Y. Q., Day, J. W., Ehsani, M., Heng, A. R., Zhen, E. Y., Davies, J., Glaesner, W., Jones, B. E., Siegel, R. W., Qian, Y., & Konrad, R. J. (n.d.). An anti-ANGPTL3/8 antibody decreases circulating triglycerides by binding to a LPL-inhibitory leucine zipper-like motif.Journal of Lipid Research,63(5), 100198.

Deepa Balasubramaniam, Oliver Schroeder, Anna M. Russell, Jonathan R. Fitchett, Aaron K. Austin, Thomas P. Beyer, Yan Q. Chen, Jonathan W. Day, Mariam Ehsani, Aik Roy Heng, Eugene Y. Zhen, Julian Davies, Wolfgang Glaesner, Bryan E. Jones, Robert W. Siegel, Yue-Wei Qian, Robert J. Konrad
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