Concurrent Compression of Phospholipid Membranes by Calcium and Cholesterol

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F19%3A00517192" target="_blank" >RIV/61388955:_____/19:00517192 - isvavai.cz</a>

Alternative codes found

RIV/67985823:_____/19:00517192 RIV/61388963:_____/19:00510533

Result on the web

<a href="http://hdl.handle.net/11104/0302482" target="_blank" >http://hdl.handle.net/11104/0302482</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.langmuir.9b00477" target="_blank" >10.1021/acs.langmuir.9b00477</a>

Result language

angličtina

Original language name

Concurrent Compression of Phospholipid Membranes by Calcium and Cholesterol

Original language description

Regulation of cell metabolism, membrane fusion, association of proteins with cellular membranes, and cellular signaling altogether would not be possible without Ca2+ ions. The distribution of calcium within the cell is uneven with the negatively charged inner leaflet of the plasma membrane being one of the primary targets of its accumulation. Therefore, we decided to map the influence of Ca2+ on the properties of lipid bilayers closely resembling natural lipid membranes. We combined fluorescence spectroscopy (analysis of time-resolved emission spectra of Laurdan probe and derived parameters: integrated relaxation time related to local lipid mobility, and total emission shift reflecting membrane polarity and hydration) with molecular dynamics simulations to determine the effect of the increasing CaCl2 concentration on model lipid membranes containing POPC, POPS, and cholesterol. On top of that, the impact of calcium on the plasma membranes isolated from HEK293 cells was investigated using the steady-state fluorescence of Laurdan. We found that calcium increases rigidity of all the model lipid membranes used, elevates their thickness, increases lipid packing and ordering, and impedes the local lipid mobility. All these effects were to a great extent similar to those elicited by cholesterol. However, the changes of the membrane properties induced by calcium and cholesterol seem largely independent from each other. At sufficiently high concentrations of calcium or cholesterol, the steric effects hindered a further alteration of membrane organization, i.e., the compressibility limit of membrane structures was reached. We found no indication for mutual interaction between Ca2+ and cholesterol, nor competition of Ca2+ ions and hydroxyl groups of cholesterol for binding to phospholipids. Fluorescence measurements indicated that Ca2+ adsorption decreases mobility within the carbonyl region of model bilayers more efficiently than monovalent ions do (Ca2+ >> Li+ > Na+ > K+ > Cs+). The effects of calcium ions were to a great extent mitigated in the plasma membranes isolated from HEK293 cells when compared to the model lipid membranes. Noticeably, the plasma membranes showed remarkably higher resistance toward rigidification induced by calcium ions even when compared with the model membranes containing cholesterol.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Langmuir

ISSN

0743-7463

e-ISSN

—

Volume of the periodical

35

Issue of the periodical within the volume

35

Country of publishing house

US - UNITED STATES

Number of pages

11

Pages from-to

11358-11368

UT code for WoS article

000484644000015

EID of the result in the Scopus database

2-s2.0-85071784813