Abstract
Cardiolipin (CL) plays an important role in administering the structural organization of biological membranes and therefore helps maintaining the integer membrane functionality. CL has a dimeric structure consisting of four acyl chains and two phosphate groups. With its unusual structure, the phospholipid is responsible for curvature formation in CL containing biological membranes. The acidic properties of the phosphate head groups are still not sufficiently investigated since there are controversial results in literature. The main aim of this work was to gain deeper insights into the influence of the pH on the ionization degree of CL. During the experiments, it became clear that the used ultrapure water contained traces of calcium. These unexpected calcium ions had a major impact on the behavior of CL monolayers. Therefore, the focus was put on the analysis of CL layers without and with EDTA in the subphase used to complex divalent calcium ions. For the analyses, traditional surface pressure (π) - molecular area (A) isotherm experiments combined with total reflection x-ray fluorescence (TRXF) and grazing incidence x-ray diffraction (GIXD) have been used.
Highlights
The anionic phospholipid cardiolipin (CL) has been found in bacterial and mitochondrial membranes.[1]
total reflection x-ray fluorescence (TRXF) was the method of choice to determine the ionization degree of the phosphate head groups based on the concentration of the corresponding counterions in the electrical double layer (EDL) near a charged surface
The results presented in this work show that the ultrapure water used for the experiments contained traces of calcium
Summary
The anionic phospholipid cardiolipin (CL) has been found in bacterial and mitochondrial membranes.[1] There, it fulfills a crucial function in maintaining the integer functionality of biological membranes as it takes part in regulating their structural organization.[2] The reasons for that important feature of CL are based in its dimeric structure.[3] With four alkyl chains and a relatively small head group, the phospholipid features a conical shape which induces negative curvature formation in CL containing membranes.[4,5,6,7] Modifying the packing of the lipid can lead to structural changes and instabilities in the shape of the membrane.[1,8,9] By means of controlled environmental alterations, these changes can be investigated
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Chemphyschem : a European journal of chemical physics and physical chemistry
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
