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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Α-Tocopherol Is Well Designed To Protect Polyunsaturated Phospholipids: Md Simulations, Xiaoling Leng, Jacob J. Kinnun, Drew Marquardt, Mikel Ghefli, Norbert Kučerka, John Katsaras, Jeffrey Atkinson, Thad A. Harroun, Scott E. Feller, Stephen R. Wassall
Α-Tocopherol Is Well Designed To Protect Polyunsaturated Phospholipids: Md Simulations, Xiaoling Leng, Jacob J. Kinnun, Drew Marquardt, Mikel Ghefli, Norbert Kučerka, John Katsaras, Jeffrey Atkinson, Thad A. Harroun, Scott E. Feller, Stephen R. Wassall
Chemistry and Biochemistry Publications
The presumptive function for alpha-tocopherol (αtoc) in membranes is to protect polyunsaturated lipids against oxidation. Although the chemistry of the process is well established, the role played by molecular structure that we address here with atomistic molecular-dynamics simulations remains controversial. The simulations were run in the constant particle NPT ensemble on hydrated lipid bilayers composed of SDPC (1-stearoyl-2-docosahexaenoylphosphatidylcholine, 18:0-22:6PC) and SOPC (1-stearoyl-2-oleoylphosphatidylcholine, 18:0-18:1PC) in the presence of 20 mol % αtoc at 37°C. SDPC with SA (stearic acid) for the sn-1 chain and DHA (docosahexaenoic acid) for the sn-2 chain is representative of polyunsaturated phospholipids, while SOPC with OA (oleic …
Neutron Scattering At The Intersection Of Heart Health Science And Biophysics, Drew Marquardt, Richard J. Alsop, Maikel C. Rheinstädter, Thad A. Harroun
Neutron Scattering At The Intersection Of Heart Health Science And Biophysics, Drew Marquardt, Richard J. Alsop, Maikel C. Rheinstädter, Thad A. Harroun
Chemistry and Biochemistry Publications
There is an urgent quest for improved heart health. Here, we review how neutron radiation can provide insight into the molecular basis of heart health. Lower cholesterol, a daily intake of aspirin and supplemental vitamin E are argued to all improve heart health. However, the mechanisms behind these common regimens, and others, are not entirely understood. It is not clear why a daily intake of aspirin can help some people with heart disease, and the benefits of vitamin E in the treatment of reperfusion injury have been heavily debated. The molecular impact of cholesterol in the body is still a …
Asymmetric Lipid Membranes: Towards More Realistic Model Systems, Drew Marquardt, Barbara Geier, Georg Pabst
Asymmetric Lipid Membranes: Towards More Realistic Model Systems, Drew Marquardt, Barbara Geier, Georg Pabst
Chemistry and Biochemistry Publications
Despite the ubiquity of transbilayer asymmetry in natural cell membranes, the vast majority of existing research has utilized chemically well-defined symmetric liposomes, where the inner and outer bilayer leaflets have the same composition. Here, we review various aspects of asymmetry in nature and in model systems in anticipation for the next phase of model membrane studies.
Substrate-Assisted And Enzymatic Pretransfer Editing Of Nonstandard Amino Acids By Methionyl-Trna Synthetase, Grant B. Fortowsky, Daniel J. Simard, Mohamed M. Aboelnga, James W. Gauld
Substrate-Assisted And Enzymatic Pretransfer Editing Of Nonstandard Amino Acids By Methionyl-Trna Synthetase, Grant B. Fortowsky, Daniel J. Simard, Mohamed M. Aboelnga, James W. Gauld
Chemistry and Biochemistry Publications
Aminoacyl-tRNA synthetases (aaRSs) are cen- tral to a number of physiological processes, including protein biosynthesis. In particular, they activate and then transfer their corresponding amino acid to the cognate tRNA. This is achieved with a generally remarkably high fidelity by editing against incorrect standard and nonstandard amino acids. Using docking, molecular dynamics (MD), and hybrid quantum mechanical/molecular mechanics methods, we have inves- tigated mechanisms by which methionyl-tRNA synthetase (MetRS) may edit against the highly toxic, noncognate, amino acids homocysteine (Hcy) and its oxygen analogue, homo- serine (Hse). Substrate-assisted editing of Hcy-AMP in which its own phosphate acts as the mechanistic …
Aspirin Inhibits Formation Of Cholesterol Rafts In Fluid Lipid Membranes, Richard J. Alsop, Laura Toppozini, Drew Marquardt, Norbert Kučerka, Thad A. Harroun, Maikel C. Rheinstädter
Aspirin Inhibits Formation Of Cholesterol Rafts In Fluid Lipid Membranes, Richard J. Alsop, Laura Toppozini, Drew Marquardt, Norbert Kučerka, Thad A. Harroun, Maikel C. Rheinstädter
Chemistry and Biochemistry Publications
Aspirin and other non-steroidal anti-inflammatory drugs have a high affinity for phospholipid membranes, altering their structure and biophysical properties. Aspirin has been shown to partition into the lipid head groups, thereby increasing membrane fluidity. Cholesterol is another well known mediator of membrane fluidity, in turn increasing membrane stiffness. As well, cholesterol is believed to distribute unevenly within lipid membranes leading to the formation of lipid rafts or plaques. In many studies, aspirin has increased positive outcomes for patients with high cholesterol. We are interested if these effects may be, at least partially, the result of a non-specific interaction between aspirin …