Role of 1, 2-dioleoyl-3-trimethylammonium-propane (DOTAP) in β-lactoglobulin aggregation. (January 2018)

• Record Type: Journal Article
• Authors: Ma, Baoliang; Wang, Xiaofei; Liu, Yujie; Li, Zhihong; Zhang, Fan
• Is Part Of: Chemistry and physics of lipids. Volume 210(2018)
• Page Start: 76
• Page End: 81
• Publication Date: 2018-01
• Subjects: Amyloid aggregation -- Spherical aggregation -- 1, 2-dioleoyl-3-trimethylammonium-propane(DOTAP) -- β-lactoglobulin (β-LG) -- Critical micelle concentration (CMC); Lipids -- Periodicals; Lipids -- Periodicals; Lipides -- Périodiques; Lipids; Periodicals; Electronic journals; 547.77
• DOI: 10.1016/j.chemphyslip.2017.11.007
• Languages: English
• ISSNs: 0009-3084

Abstract

Graphical abstract: Highlights: The critical micelle concentration of DOTAP at pH 2.0 and 80 °C is approximately 62 μM. DOTAP below the CMC inhibits the amyloid fibril formation of β-lactoglobulin. DOTAP above the CMC enhances the amyloid aggregate formation of β-lactoglobulin, but the aggregates are spherical aggregates. Abstract: Protein aggregation is a prevalent phenomenon. It is important to study protein aggregation under different solution conditions. In this study, using 1-anilinonaphthalene-8-sulfonic acid (ANS) fluorescence spectra, we investigated the critical micelle concentration (CMC) of 1, 2-dioleoyl-3-trimethylammonium-propane (DOTAP). We also studied the effects of DOTAP on amyloid aggregation of β-lactoglobulin using intrinsic fluorescence spectra, circular dichroism spectra, thioflavin T fluorescence, a Congo red binding assay and transmission electron microscopy. We observed that DOTAP had a dual role on β-lactoglobulin amyloid aggregation. DOTAP inhibited the amyloid aggregation below the CMC, while it had the opposite effect above the CMC. Moreover, the results of transmission electron microscopy showed that spherical aggregates were formed above the CMC. These results led us to conclude that cationic lipids could be used as modulators of protein self-assembly.