Seeking for a modified lipoprotein present in plasma that could account for the atherogenic effect of high cholesterol, several years ago electronegative LDL(−) was identified. The peculiar feature of LDL(−) is an apoprotein misfolding that triggers the formation of aggregates, perfectly fitting in size the subendothelial droplets observed in early phases of atherogenesis. Apoprotein misfolding was therefore proposed as a possible atherogenic modification. LDL(−) can be spontaneously produced in vitro by plasma incubation through phospholipid hydrolysis catalyzed by the activity of endogenous phospholipases. As a consequence, apoprotein is misfolded. 17β-Estradiol (E2), a specific ligand to apoB-100, was used to unravel the relationship between negative charge of the lipoprotein and apoprotein structural/conformational shift. Although E2 addition to plasma does not prevent LDL(−) generation nor phospholipase activity, it deeply stabilizes apoB-100 structure, thus preventing its structural and conformational shift. Apoprotein stabilization extends to lipids. Indeed, while a loosening of lipid packing is observed together with apoprotein misfolding, conversely, when E2 stabilizes apoprotein, lipid structure is preserved. Finally, even in the presence of LDL(−), the E2-stabilized LDL is resistant to aggregation, unambiguously demonstrating that misfolding, but not negative charge, primes aggregation. In conclusion, electronegative charge and misfolding are independent and distinct features of LDL(−), and apoprotein misfolding rather than the increase in the negative charge emerges both as a valid biomarker and as an appealing pharmacological and nutritional target.

De Spirito, M., Estradiol Binding Prevents ApoB-100 Misfolding in Electronegative LDL(−), <<BIOCHEMISTRY>>, 2010; 2010 (49): 7297-7303 [http://hdl.handle.net/10807/6544]

Estradiol Binding Prevents ApoB-100 Misfolding in Electronegative LDL(−)

De Spirito, Marco
2010

Abstract

Seeking for a modified lipoprotein present in plasma that could account for the atherogenic effect of high cholesterol, several years ago electronegative LDL(−) was identified. The peculiar feature of LDL(−) is an apoprotein misfolding that triggers the formation of aggregates, perfectly fitting in size the subendothelial droplets observed in early phases of atherogenesis. Apoprotein misfolding was therefore proposed as a possible atherogenic modification. LDL(−) can be spontaneously produced in vitro by plasma incubation through phospholipid hydrolysis catalyzed by the activity of endogenous phospholipases. As a consequence, apoprotein is misfolded. 17β-Estradiol (E2), a specific ligand to apoB-100, was used to unravel the relationship between negative charge of the lipoprotein and apoprotein structural/conformational shift. Although E2 addition to plasma does not prevent LDL(−) generation nor phospholipase activity, it deeply stabilizes apoB-100 structure, thus preventing its structural and conformational shift. Apoprotein stabilization extends to lipids. Indeed, while a loosening of lipid packing is observed together with apoprotein misfolding, conversely, when E2 stabilizes apoprotein, lipid structure is preserved. Finally, even in the presence of LDL(−), the E2-stabilized LDL is resistant to aggregation, unambiguously demonstrating that misfolding, but not negative charge, primes aggregation. In conclusion, electronegative charge and misfolding are independent and distinct features of LDL(−), and apoprotein misfolding rather than the increase in the negative charge emerges both as a valid biomarker and as an appealing pharmacological and nutritional target.
Inglese
De Spirito, M., Estradiol Binding Prevents ApoB-100 Misfolding in Electronegative LDL(−), <<BIOCHEMISTRY>>, 2010; 2010 (49): 7297-7303 [http://hdl.handle.net/10807/6544]
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10807/6544
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