Abstract 10516: Identification of a PCSK9-LDLR Disruptor Macrocycle with in vivo Function
| Autor: | Margaret E Brousseau, Kevin B Clairmont, Glen Spraggon, Alec N Flyer, Andrei A Golosov, Philipp Grosche, Jérôme André, Shari Caplan, Guanjing Chen, Li Fan, Raphael Gattlen, Alexander Koch, Ian Lewis, Jingzhou Li, Eugene Liu, Danuta Lubicka, Andreas Marzinzik, Katsumasa Nakajima, David Nettleton, Johannes Ottl, Meihui Pan, Tajesh Patel, Stephanie Pickett, Jennifer Poirier, Patrick C Reid, Xavier Pelle, Vanitha Subramanian, Victoria Vera, Mei Xu, Lihua Yang, Qing Yang, jinghua yu, Guoming Zhu, Lauren G Monovich |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Circulation. 144 |
| ISSN: | 1524-4539 0009-7322 |
| Popis: | Elevated LDL-C is a major risk factor for atherosclerotic cardiovascular disease, the leading cause of death worldwide. Proprotein convertase subtilisin/kexin type 9 (PCSK9) has pronounced effects on LDL-C levels via its modulation of hepatic LDL receptors (LDLR), the main pathway for cholesterol removal from the circulation. The epidermal growth factor precursor homology domain A (EGF-A) of the LDLR serves as a primary contact with PCSK9 via a flat interface, presenting a challenge for identifying small molecule PCSK9-LDLR disruptors. We employed an affinity-based screen of 10 13 in vitro -translated macrocyclic peptides to identify high affinity PCSK9 ligands that utilize a novel, induced-fit pocket and partially disrupt the PCSK9-LDLR interaction (Hit 1 - PCSK9-LDLR FRET, IC 50 2 nM, A max 41%). Structure-based design led to 13 PCSK9i , a molecule with enhanced in vitro function (PCSK9-LDLR FRET, IC 50 2 nM, A max 78%) and pharmacokinetic properties suitable for in vivo evaluation. To determine if 13 PCSK9i ’s functional activity in vitro would translate in vivo , C57BL/6 mice were dosed with vehicle or 13 PCSK9i via subcutaneous injection twice-daily for 3 days, and blood and liver were collected for the measurement of plasma total cholesterol (TC) and hepatic LDLR density. A PCSK9 antibody was included as a positive control. As illustrated in the figure, 13 PCSK9i increased hepatic LDLR density in a dose-dependent manner. Despite being 1/100 th its size, 13 PCSK9i (MW = 1.65 kDa) increased hepatic LDLR density on par with a PCSK9 antibody (MW = 144 kDa). Plasma TC levels were significantly reduced versus vehicle in all 13 PCSK9i dose groups, with similar reductions noted in the 13 PCSK9i 30 mg/kg and PCSK9 antibody groups (44% and 48%, respectively). In summary, 13 PCSK9i breaks new ground with its previously undescribed allosteric mechanism and, in turn, as the smallest molecule identified to date with in vivo PCSK9-LDLR disruptor function. |
| Databáze: | OpenAIRE |
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