Phospholipid environment

Johansson A, Curstedt T, Robertson B, et al. 1983. Rabbit lung after inhalation of soluble nickel. II. Effects of lung tissue and phospholipids. Environ Res 31 399-412. 

In an attempt to find a better way of considering the interfacial region, molecular dynamics simulations of different helices were performed in phospholipid environ-... 

ER of adrenal, testis, ovary, liver and placenta. It is relatively unstable, being inactivated by freezing, even when pure. A phospholipid environment appears to be an important requirement since, when bovine adrenal microsomal preparations were treated with phospholipase A, 80-85% of phospholipids were hydrolysed with a concomitant loss of 80-90% of enzymic activity [84], Restoration of activity was achieved by adding back to the lipid-depleted membranes aqueous dispersions of microsomal total lipid mixtures [84],... 

The a subunit is the most essential component of an ion channel. It is an integral membrane protein that requires a phospholipid environment to maintain a functional three-dimensional structure. Most a subunits are capable of forming functional channels when expressed alone in an artificial system, but they are often associated in native systems with transmembrane or cytosolic auxiliary subunits that modulate and fine-tune the properties of the channel. It is important to note that ion channel subunits often co-assemble in a tissue-specific manner and sometimes the expression patterns of individual subunits may be altered in disease. Therefore, when one is developing an assay using a heterologously expressed ion channel target, it is always preferable to employ a combination of subunits appropriate to the tissue and/or disease of interest. 

In addition to reacting with ChEs, OPs and other antl-ChEs also can react with other critical molecules In nerves or In effector organs. OP drugs may exert direct effects on the cholinergic receptor or on Its phospholipid environment, at both CNS and PNS synapses (34-38). OPs also react with other neural and metabolic enzymes, and some of them are capable of alkylating DNA. The biologic consequences of these reactions are not as well understood as are those Inhibiting ChE ... 

Weissbuch, I., Rubinstein, I., Weygand, M.J., Kjaer, K., Leiserowitz L Lahav, M. CrystalUnephase separation of racemic and nonracemic zwitterionic a -amino acid amphiphiles in a phospholipid environment at the air/water interface a grazing-incidence X-Ray diffraction study, Helv. Chim. 

Carboxamides are a group of fungicides that control diseases caused by Basidiomycete type fungi (42). The best known member of this group is carboxin (Figure 6). Carboxamides specifically block membrane bound succinate-ubiquinone oxldoreductase activity in the mitochondrial electron transport chain (42, ). The carboxin receptor in the succinic dehydrogenase complex (SDC) is believed to be the iron-sulfur cluster Sj complexed with small coenzyme Q binding polypeptide(s) in a phospholipid environment (45.46 >. 

Similar results were obtained for the polymerization of nomacemic C18-Lys-TE within a phospholipid environment, where the ethanolamine group of the phospholipid served as the initiator of the reaction [25]. 

A DFT mechanistic study of the formation of Schiff bases from acetaldehyde in water has looked at two amines of biological importance glycine and phosphatidylethanolamine, with an amine-phospholipid monolayer model being incorporated in the latter. The rate-determining step was found to be dehydration of the carbinolamine intermediate in both cases. Relative free energies of the intermediates and transition states were lower (compared to butylamine as a reference amine), these effects being ascribed to the carboxylic group and phospholipid environment, respectively. 

Obviously, as with G-6-Pase, the native phospholipid environment is not essential for the full activity in vitro of UDP-glucuronyltransferase, but acts to constrain it. In contrast to G-6-Pase, however, the exact relation between lipids and enzyme activity is more complex for UDP-glucuronyltransferase, since there are more forms of this enzyme than a constrained and a fully active form. Another important point is that despite the basic similarity in the protein-lipid interactions for UDP-glucuronyltransferase and G-6-Pase, careful comparison of the detailed effects of phospholipases on the activities of each enzyme reveal significant differences in their behavior (Vessey and Zakim, 1971). Thus, although phospholipid-induced constraint and its relaxation appear to be general characteristics of some microsomal enzymes in vitro, the details of the interactions between enzymes and microsomal phospholipids vary for different enzymes. 

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