1. Molecular basis for the protective effects of low-density lipoprotein receptor-related protein 1 (LRP1)-derived peptides against LDL aggregation.
- Author
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Benitez-Amaro, Aleyda, Pallara, Chiara, Nasarre, Laura, Rivas-Urbina, Andrea, Benitez, Sonia, Vea, Angela, Bornachea, Olga, de Gonzalo-Calvo, David, Serra-Mir, Gabriel, Villegas, Sandra, Prades, Roger, Sanchez-Quesada, José Luís, Chiva, Cristina, Sabido, Eduard, Tarragó, Teresa, and Llorente-Cortés, Vicenta
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LIPOLYSIS , *LOW density lipoproteins , *PEPTIDES , *GEL permeation chromatography , *POLYACRYLAMIDE gel electrophoresis , *MOLECULAR interactions - Abstract
Aggregated LDL is the first ligand reported to interact with the cluster II CR9 domain of low-density lipoprotein receptor-related protein 1 (LRP1). In particular, the C-terminal half of domain CR9, comprising the region Gly1127-Cys1140 exclusively recognizes aggregated LDL and it is crucial for aggregated LDL binding. Our aim was to study the effect of the sequence Gly1127-Cys1140 (named peptide LP3 and its retro- enantio version, named peptide DP3) on the structural characteristics of sphingomyelinase- (SMase) and phospholipase 2 (PLA 2)-modified LDL particles. Turbidimetry, gel filtration chromatography (GFC) and transmission electronic microscopy (TEM) analysis showed that LP3 and DP3 peptides strongly inhibited SMase- and PLA 2 -induced LDL aggregation. Nondenaturing polyacrylamide gradient gel electrophoresis (GGE), agarose gel electrophoresis and high-performance thin-layer chromatography (HPTLC) indicated that LP3 and DP3 prevented SMase-induced alterations in LDL particle size, electric charge and phospholipid content, respectively, but not those induced by PLA 2. Western blot analysis showed that LP3 and DP3 counteracted changes in ApoB-100 conformation induced by the two enzymes. LDL proteomics (LDL trypsin digestion followed by mass spectroscopy) and computational modeling methods evidenced that peptides preserve ApoB-100 conformation due to their electrostatic interactions with a basic region of ApoB-100. These results demonstrate that LRP1-derived peptides are protective against LDL aggregation, even in conditions of extreme lipolysis, through their capacity to bind to ApoB-100 regions critical for ApoB-100 conformational preservation. These results suggests that these LRP1(CR9) derived peptides could be promising tools to prevent LDL aggregation induced by the main proteolytic enzymes acting in the arterial intima. Fig. 8 Schematic representation of the molecular basis for the protective effect of LRP1-derived peptides against SMase- and PLA 2 -induced LDL aggregation. DP3 forms a complex with ApoB-100 and this molecular interaction stabilizes ApoB-100 conformation. ApoB-100 conformation stabilization might guarantee the structural preservation of surface colesterol-enriched environments, where SM is located. Structural preservation of cholesterol, a key regulator of phospholipolysis, would protect SM from SMase activity. As a result, LDL complexed with DP3 remains unaltered when exposed to SMase. This scenario changes when LDL complexed with DP3 is exposed to PLA 2. The target for PLA 2 is PC, phospholipid associated with poor-colesterol environments. Therefore, PC is unprotected against the attack of PLA2, that hydrolyzes PC producing lysoPC and NEFA. Remarkably, LDL complexed with DP3 is protected against SMase and PLA2-induced aggregation even in conditions of extreme phospholipolysis, indicating that the maintenance of ApoB-100 conformation is enough to prevent LDL aggregation. Unlabelled Image • LRP1-peptides prevent SMase-induced alterations in LDL size, charge and phospholipid content. • LRP1-peptides do not prevent PLA 2 -induced alterations in LDL size, charge and phospholipid content. • LRP1-peptides prevent LDL aggregation through electrostatical interaction with basic ApoB-100 sequences. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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