Amphipathic

Amphipathic adj.

All living cells are surrounded by a cell membrane. Plant cells and animal cells contain a cell nucleus that is also surrounded by a membrane and holds the genetic information for the cell. Everything between the cell membrane and the nuclear membrane, including intracellular fluids and various subcellular components such as the mitochondria and ribosomes is called the cytoplasm. The lipids in cell membranes are amphipathic. They have dual characteristics: part of the lipid is ionic and therefore dissolves in water, whereas the rest has a hydrocarbon structure and therefore dissolves in nonpolar substances. The amphipathic lipids commonly found in membranes are phospholipids and glycolipids.

Amphipathic

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'amphipathic. Send us feedback about these examples. Accessed 4 Mar. Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! See Definitions and Examples ». Log In. Examples of amphipathic in a Sentence. Recent Examples on the Web Emulsifiers are amphipathic compounds, meaning the molecule has both a polar and nonpolar section. Levy, Wired , 30 Nov. Word History. First Known Use.

It is a major component of cell membranes.

One of the fundamental features of biomembranes is the ability to fuse or to separate. These processes called respectively membrane fusion and fission are central in the homeostasis of events such as those related to intracellular membrane traffic. Proteins that contain amphipathic helices AHs were suggested to mediate membrane fission via shallow insertion of these helices into the lipid bilayer. AH-containing fission-inducing proteins may require cofactors such as additional proteins e. Instead, PtdIns 4,5 P 2 is characterized by an high negative charge able to recruit basic residues of the AHs of fission-inducing proteins. Following our analysis, we show that the AHs of many fission-inducing proteins possess five properties: a at least three basic residues on the hydrophilic side, b ability to oligomerize, c optimal shallow depth of insertion into the membrane, d positive cooperativity in membrane curvature generation, and e specific interaction with one of the lipids mentioned above.

All living cells are surrounded by a cell membrane. Plant cells and animal cells contain a cell nucleus that is also surrounded by a membrane and holds the genetic information for the cell. Everything between the cell membrane and the nuclear membrane, including intracellular fluids and various subcellular components such as the mitochondria and ribosomes is called the cytoplasm. The lipids in cell membranes are amphipathic. They have dual characteristics: part of the lipid is ionic and therefore dissolves in water, whereas the rest has a hydrocarbon structure and therefore dissolves in nonpolar substances.

Amphipathic

Federal government websites often end in. The site is secure. Systemic amyloidosis is characterized by the extracellular deposition of misfolded proteins as insoluble amyloid fibrils in various tissues. The familial forms of amyloidosis AF comprise a group of autosomal dominant diseases associated with mutations in a number of genes encoding amyloid precursor proteins.

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Conical lipids in flat bilayers induce packing defects similar to that induced by positive curvature. Life Sci. A small AH of 12 aa is present in the SM sequence, containing several large hydrophobic residues and a poorly developed polar face. Eriksson S. Nicot et al. Enzyme function is regulated by its localization. Zemel, A. Here we describe a unique class of small molecules that exhibit both function and a binding profile analogous to natural transcriptional activation domains. Amphipathic helices peptides from diverse yeast species as well as from the human Pex11 orthologue induce strong tubulation of negatively charged liposomes [ 24 ]. Lipid Bilayers The membranes of all cells have a fundamentally similar structure. Eisenberg, D. Like many other heat shock proteins, Hsp12 is present in cells at a low copy number under standard growth conditions but can be induced more than fold by harsh conditions. Chemical solutions. The role that AHs play in the function of fission-inducing proteins is emphasized by the fact that few naturally occurring mutations of residues belonging to the AHs are associated with human diseases. In contrast, isoxazolidine 5 exhibits a different binding profile.

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Also, they facilitate cellular recognition, which is essential in immunologic functions. It can specifically interact with membrane proteins to regulate their function by filling a selective cholesterol-binding pocket [ 58 ], but it is less clear whether an AH could specifically contact a cholesterol molecule embedded in a bilayer. Loftus, A. Saksena, S. Structural and functional insights into the cryoprotection of membranes by the intrinsically disordered dehydrins. Grammar Patterns. Toggle limited content width. Chembiochem 15, — Parton, R. Small nonpolar molecules can readily diffuse to their concentration gradient across the membrane whereas polar molecules will be prohibited from doing so. Cooperation of helix insertion and lateral pressure to remodel membranes. Gaspar M. Structure versus stochasticity-the role of molecular crowding and intrinsic disorder in membrane fission. On top of its role in autophagy, Atg18 also mediates vacuole fission Gopaldass et al. It should be emphasized that the role of epsins in the formation and fission of CCVs is somewhat similar to the role of Sar1 and Arf1 in the formation and fission of COP vesicles Boucrot et al.