Author(s):
Janek, Tomasz ; Czyznikowska, Zaneta ; Luczynski, Jacek ; Gudiña, Eduardo J. ; Rodrigues, L. R. ; Galezowska, Joanna
Date: 2017
Persistent ID: https://hdl.handle.net/1822/46437
Origin: RepositóriUM - Universidade do Minho
Project/scholarship:
info:eu-repo/grantAgreement/FCT/5876/147337/PT;
info:eu-repo/grantAgreement/FCT/5876-PPCDTI/126270/PT
;
info:eu-repo/grantAgreement/FCT/COMPETE/126270/PT;
Subject(s): Lysosomotropic substances; Surface tension; Density functional theory; Fluorescence quenching; Circular dichroism; Isothermal titration calorimetry; Science & Technology
Description
The interactions between two cationic lysosomotropic surfactants (2-dodecanoyloxyethyl)trimethylammonium bromide (DMM-11) and (2-dodecanoyloxypropyl)trimethylammonium bromide (DMPM-11) with bovine serum albumin (BSA) in Hepes buffer (pH = 7.4) were systematically studied by surface tension, fluorescence and circular dichroism (CD) spectroscopy and isothermal titration calorimetry (ITC). Furthermore, the size of the micellar aggregates and the polydispersity indexes of both cationic surfactants were studied by dynamic light scattering technique (DLS). The hydrodynamic radii, micellar volumes and aggregation numbers were calculated using a method based on density functional theory (DFT). The results showed that, in both cases, the surface tension was modified upon addition of BSA, and the critical micelle concentration (CMC) values of DMM-11 and DMPM-11 were higher in the presence of BSA. The fluorescence intensity of BSA decreased significantly as the concentration of both cationic surfactants increased and this effect was attributed to the formation of surfactant-BSA complexes. Synchronous fluorescence spectrometry showed the binding-induced conformational changes in BSA. Finally, CD and DLS results revealed the occurrence of changes in the secondary structure of the protein in the presence of both surfactants. In conclusion, understanding the interactions between lysosomotropic surfactants and BSA is required to explore their potential applications in medicine.
Author Żaneta Czyżnikowska gratefully acknowledge the allotment of the CPU time in Wroclaw Center of Networking and Supercomputing (WCSS). All the ITC experiments were performed by Joanna Gałęzowska in the Laboratory of Elemental Analysis and Structural Research, Faculty of Pharmacy and the Division of Laboratory Diagnostics, Wroclaw Medical University, supported by the ERDF Project within the Innovation Economy Operational Programme POIG.02.01.00-14-122/09”. Ligia R. Rodrigues and Eduardo J. Gudiña acknowledge the Portuguese Foundation for Science and Technology (FCT) for the financial support under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 − Programa Operacional Regional do Norte. The authors also thank the FCT for the financial support under the scope of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). This work was supported by Polish-Portugal Executive Program for years 2017-2018.
info:eu-repo/semantics/publishedVersion
