Role of head group structure in the phase behavior of amino phospholipids. 1. Hydrated and dehydrated lamellar phases of saturated phosphatidylethanolamine analogs

Biochemistry ◽  
1986 ◽  
Vol 25 (15) ◽  
pp. 4249-4258 ◽  
Author(s):  
John R. Silvius ◽  
Pamela M. Brown ◽  
Timothy J. O'Leary
Keyword(s):  
Phase Behavior ◽  
Group Structure ◽  
Head Group ◽  
Lamellar Phases

Role of head group structure in the phase behavior of amino phospholipids. 2. Lamellar and nonlamellar phases of unsaturated phosphatidylethanolamine analogs

Biochemistry ◽  
1986 ◽  
Vol 25 (15) ◽  
pp. 4259-4267 ◽  
Author(s):  
Pamela M. Brown ◽  
John Steers ◽  
Sek Wen Hui ◽  
Philip L. Yeagle ◽  
John R. Silvius
Keyword(s):  
Phase Behavior ◽  
Group Structure ◽  
Head Group

Long-Range Interactions and Rigidity in Surfaces and Lamellar Phases

1989 ◽  
Vol 177 ◽  
Author(s):  
Mehran Kardar
Keyword(s):  
Phase Behavior ◽  
Long Range ◽  
Experimental Activity ◽  
Lamellar Phases ◽  
Long Range Interactions ◽  
Large Effort

ABSTRACTRecently there has been a large effort to understand the statistical and phase behavior of collections of surfaces and membranes. Experimental activity has focused on the behavior of stacked films in lamellar phases of microemulsions. Here I briefly sumnmarize the role of fluctuations and undulations in four classes of films: fluid, hexatic, solid, and charged.

scholarly journals Simulation Study of the Structure and Phase Behavior of Ceramide Bilayers and the Role of Lipid Headgroup Chemistry

2013 ◽  
Vol 9 (11) ◽  
pp. 5116-5126 ◽  
Author(s):  
Shan Guo ◽  
Timothy C. Moore ◽  
Christopher R. Iacovella ◽  
L. Anderson Strickland ◽  
Clare McCabe
Keyword(s):  
Phase Behavior ◽  
Simulation Study

Self-assembling systems based on amphiphilic alkyltriphenylphosphonium bromides: Elucidation of the role of head group

2012 ◽  
Vol 367 (1) ◽  
pp. 327-336 ◽  
Author(s):  
Gulnara A. Gainanova ◽  
Guzalia I. Vagapova ◽  
Victor V. Syakaev ◽  
Alsu R. Ibragimova ◽  
Farida G. Valeeva ◽  
...  
Keyword(s):  
Head Group ◽  
Self Assembling

Electron Transport from QA to Thymoquinone in a Synechococcus Oxygen-Evolving Photosystem II Preparation: Role of QB and Binding Affinity of Thymoquinone to the QB Site

1993 ◽  
Vol 48 (3-4) ◽  
pp. 174-178 ◽  
Author(s):  
Kazuhiko Satoh ◽  
Yasuhiro Kashino ◽  
Hiroyuki Koike
Keyword(s):  
Binding Affinity ◽  
Turnover Rate ◽  
Side Chain ◽  
Head Group ◽  
Binding Affinities ◽  
Ps Ii ◽  
Thermophilic Cyanobacteria ◽  
High Concentrations ◽  
Oxygen Evolving

Abstract We have recently shown that binding affinities of benzoquinones can be estimated by two methods in photosystem (PS) II particles (K. Satoh et al., Biochim. Biophys. Acta 1102, 45-52 (1992)). Using these methods we calculated the binding affinity of thymoquinone (2-methyl-5-isopropyl-p-benzoquinone) to the QB site and studied how the quinone accepts electrons in oxygen-evolving PS II particles isolated from the thermophilic cyanobacteria, Synechococcus elongatus and S. vulcanus. The results are as follows: (1) The binding constant of thymoqui­ none to the QB site determined by several methods was around 0.33 mᴍ . (2) At low thymoquinone concentrations the quinone was supposed to accept electrons via QB-plastoquinone, whereas at high concentrations the quinone seemed to bind to the QB site and accept an electron directly from Q-A. Lower rates of photoreduction of the quinone at high concentrations were attributed to a slower turnover rate of the quinone at the QB site than that of endogenous plastoquinone. (3) A model for the function of plastoquinone at the QB site, which can explain all the results, was presented. According to this model, the plastoquinone molecule at the QB site is not replaced by another plastoquinone molecule. Instead, it transfers electrons to pool plastoquinone molecules by turning over its head group but remaining its long side chain bound to the PS II complexes.

scholarly journals Understanding the Unique Role of Phospholipids in the Lubrication of Natural Joints: An Interfacial Tension Study

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 264 ◽  
Author(s):  
Aneta D. Petelska ◽  
Katarzyna Kazimierska-Drobny ◽  
Katarzyna Janicka ◽  
Tomasz Majewski ◽  
Wiesław Urbaniak
Keyword(s):  
Interfacial Tension ◽  
Lipid Bilayers ◽  
Solid Lubricant ◽  
Solid Lubricants ◽  
Phospholipid Bilayer ◽  
Low Friction ◽  
Unique Role ◽  
Lamellar Phases ◽  
Chemical Inertness

Some solid lubricants are characterized by a layered structure with weak (van der Waals) inter-interlayer forces which allow for easy, low-strength shearing. Solid lubricants in natural lubrication are characterized by phospholipid bilayers in the articular joints and phospholipid lamellar phases in synovial fluid. The influence of the acid–base properties of the phospholipid bilayer on the wettability and properties of the surface have been explained by studying the interfacial tension of spherical lipid bilayers based on a model membrane. In this paper, we show that the phospholipid multi-bilayer can act as an effective solid lubricant in every aspect, ranging from a ‘corrosion inhibitor’ in the stomach to a load-bearing lubricant in bovine joints. We present evidence of the outstanding performance of phospholipids and argue that this is due to their chemical inertness and hydrophilic–hydrophobic structure, which makes them amphoteric and provides them with the ability to form lamellar structures that can facilitate functional sliding. Moreover, the friction coefficient can significantly change for a given phospholipid bilayer so it leads to a lamellar-repulsive mechanism under highly charged conditions. After this, it is quickly transformed to result in stable low-friction conditions.

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