Membrane mimics

These membranes mimic natural photosynthesis except that the electrons are directed to form hydrogen. Several sensitizers and catalysts are needed to complete the cycle, but progress is being made. Various siagle-stage schemes, ia which hydrogen and oxygen are produced separately, have been studied, and the thermodynamic feasibiHty of the chemistry has been experimentally demonstrated. 

Morris, K. F Gao, X. and Wong, T. C. (2004) The interactions of the HIV gp41 fusion peptides with zwitterionic membrane mimics determined by NMR spectroscopy. Biochim. Biophys. Acta 1667, 67-81. 

N-ethylmaleimide and Heat Treatments of Membranes Mimic the Effect of Guanine Nucleotides on Ligand Binding... 

One of the most smdied examples is the mimic of the enzyme cytochrome P-450 in the pores of a faujasite zeolite [196,204,225], The iron-phthalocyanine complex was encapsulated in the FAU supercage and is used as oxidation catalyst for the conversion of cyclohexane and cyclohexanone to adipic acid, an important intermediate in the nylon production. In this case the two step process using homogeneous catalysts could be replaced by a one step process using a heterogeneous catalyst [196]. This allowed better control of the selectivity and inhibited the auto oxidation of the active compound. In order to simulate a catalyst and the reaction conditions which are close to the enzymatic process, the so obtained catalyst was embedded in a polydimethylsiloxane membrane (mimics the phospholipid membrane in the living body) and the membrane was used to limit oxygen availability. With this catalyst alkanes were oxidized at room temperature with rates comparable to those of the enzyme [205]. 

Qiu L, Buie C, Reay A, Vaughn MW, Cheng KH (2011) Molecular dynamics simulations reveal the protective role of cholesterol in beta amyloid protein-induced membrane disruptions in neuronal membrane mimics. J Phys Chem B 115 9795-9812... 

More recently, these systems have been elevated to a new level of biomimetic sophistication, namely by embedding the zeolite-encapsulated complex in a polydimethylsiloxane membrane their performance could be improved even further [81]. The hydrophobic membrane mimics the pho holipid membrane in which cytochrome P-450 resides and acts as an interface between two immiscible phases (cyclohexane and aqueous 70%TBHP). 

Motesharei K and Myles D C 1994 Molecular recognition in membrane mimics—a fluorescence probe J. Am. Chem. Soc. 116 7413-14... 

Guo. J. Farrell. S. Liu. H. Uhrich, K.E. Interactions between hyperbranched unimolecular micelles and liposomes as cell membrane-mimics. Polym. Prepr. 1999, 40, 209-210. 

Different biophysical and biochemical methods require reconstitution of the receptor/chemokine complex into different membrane mimics. Many measurements can be done direcdy in detergent micelles. However, micelles are usually not the ideal environment for receptor stability and are inferior mimics of a native membrane compared to other systems Hke nanodiscs or biceUes. Reconstitution of receptor/chemokine complexes into these... 

Figure 7 The ACKR3/CXCL12 complex reconstituted into different membrane mimics. (A) The ACKR3/CXCL12 complex is stable in all three membrane mimics as indicated by the sharp peak (derivative of the CPM unfolding curves, see Fig. 6C) and the above 60 °C. (B) SDS-PAGE of ACKR3/CXCL12 sample in nanodiscs and DDM/CHS micelles.

Plant AL (1999) Supported hybrid bilayer membranes as rugged cell membrane mimics. Langmuir 15 5128-5135... 

Surface modification with thin planar films from amphiphilic block copolymers yields versatile materials with many potential applications. For instance, the wetting or lubrication behavior can be tuned in a desired way. Additionally, systems for biomaterials science can be designed. Moreover, such modifications are also effective in fields like nanoparticle synthesis or membrane mimics. These and more examples of planar surfaces functionalized with amphiphilic block copolymers will be presented. Since the possibilities for the preparation of such materials are as diverse as their potential use, a short section introducing the main preparation techniques will precede this discussion. Generally speaking, either a polymer film or a film of polymer aggregates can be deposited. In Sect. 2.1, we will discuss the preparation, structure, and applications of polymer films. The formation, structure, and application of surface aggregates follows in Sect. 2.2. 

Cross et al. have shown the utility of the application of ssNMR spectroscopy to helical membrane proteins. These are veiy difficult and challenging because of issues of expression and purification of these proteins is veiy time intensive. Here the role of the membrane environment and the influence of membrane mimics are discussed. Recent progress in expression, purification, reconstitution, sample preparation for ssNMR spectroscopy of both oriented samples and MAS samples has been shown for helical membrane protein structures. ... 

Gotten and coworkers have studied two antimicrobial peptides, piscidin 1 3 in two different bilayers (3 1 PC/PG and 1 1 PE/PG) to investigate their structure and dynamics as well as their role in membrane destabilization in bacterial cell membrane mimics and their antimicrobial capacity. They combine oriented sample solid-state NMR by measuring the dipolar couplings and N chemical shifts and MD... 

Previous C.D. studies and amino acid predictions have indicated a high fi-sheet content of the oil-body protein [6]. However, here, C.D. studies using a "membrane mimic solvent, showed a high a-helical component. 

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