Thermotropic Behavior and Structural Organization of C24:1 Sulfatide Dispersions and Its Mixtures with Cationic Bilayers

Author(s)

de Andrade, Lucas ; Duarte, Evandro L. ; Lamy, Teresa ; Rozenfeld, Julio H. K.

• Document type: Journal article
• Source: ACS OMEGA; v. N/A, p. 10-pg., 2023-02-02.

Abstract

C24:1 sulfatide (SF) is an endogenous activator of type II NKT cells. The thermotropic behavior and structure of SF dispersions and its mixtures (4.8-16.6 mol %) with cationic dioctadecyldimethylammonium bromide (DODAB) bilayers were investigated by differential scanning calorimetry and electron paramagnetic resonance spectroscopy. The non-interdigitated lamellar structures formed by pure SF display broad thermal events around 27.5 degrees C when heated and cooled. These events disappear upon mixing with DODAB, showing complete lipid miscibility. SF decreases the DODAB gel-phase packing, with a consequent decrease in phase-transition temperatures and cooperativity upon heating. In contrast, SF increases the rigidity of the DODAB fluid phase, resulting in a smaller decrease in transition temperatures upon cooling. The hysteresis between heating and cooling decreased as the SF molar fraction increased. These effects on DODAB are similar to the ones described for other glycolipids, such as alpha GalCer and beta GlcCer. This might be due to the orientation of the rigid and planar amide bond that connects their sphingoid bases and acyl chains, which result in a V-shaped conformation of the glycolipid molecules. The current results may be important to plan and develop new immunotherapeutic tools based on SF. (AU)

• FAPESP's process: 16/19077-1 - Development of novel vaccine adjuvants capable of activating CD1d-restricted T cells
• Grantee: Julio Henrique Kravcuks Rozenfeld
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/13368-4 - Nanostructured systems: from membrane biomimetic models to carriers of bioactives
• Grantee: Karin Do Amaral Riske
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/01417-6 - Structural characterization of DODAB vesicles containing C24:1 sulfatide
• Grantee: Lucas de Andrade
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 14/50983-3 - INCT 2014: complex fluids
• Grantee: Antonio Martins Figueiredo Neto
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/01593-1 - Multiple physical techniques to structurally characterize biological relevant membranes and its interactions
• Grantee: Maria Teresa Moura Lamy
• Support Opportunities: Regular Research Grants