Amphipathic

These examples amphipathic programmatically compiled from various online sources to illustrate current usage of the word 'amphipathic.

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.

Amphipathic

Federal government websites often end in. The site is secure. Small molecules that reconstitute the binding mode s of a protein and in doing so elicit a programmed functional response offer considerable advantages in the control of complex biological processes. The development challenges of such molecules are significant, however. Many protein-protein interactions require multiple points of contact over relatively large surface areas. More significantly, several binding modes can be superimposed upon a single sequence within a protein, and a true small molecule replacement must be pre-programmed for such multi-modal binding. This is the case for the transcriptional activation domain or TAD of transcriptional activators as these mofifs utilize a poorly characterized multi-partner binding profile in order to stimulate gene expression. Here we describe a unique class of small molecules that exhibit both function and a binding profile analogous to natural transcriptional activation domains. Further, a comparison of functional and non-functional small molecules indicates that an interaction with CBP is a key contributor to transcriptional activity. Taken together, the evidence suggests that the small molecule TADs mimic both the function and mechanism of their natural counterparts and thus present a framework for the broader development of small molecule transcriptional switches. Transcriptional activators are essential for high fidelity transcription, responsible for seeking out particular genes and up-regulating them to precise levels in a signal-responsive fashion.

The influence of the mutations of AH residues on the ability of AH-containing proteins to generate membrane curvature is summarized in Table 1. Amphipathic charged group may be anionic or cationic. Sandvig, amphipathic, K.

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. Phospholipids are lipids containing phosphorus.

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'amphipathic. Send us feedback about these examples. Accessed 18 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.

Amphipathic

The main difference between amphiphilic and amphipathic molecules is that amphiphilic molecules have less distinct hydrophilic and hydrophobic regions, whereas amphipathic molecules have distinct separations between hydrophilic and hydrophobic regions. Amphiphilic and amphipathic molecules are types of molecules that contain both hydrophobic and hydrophilic regions. Amphiphilic molecules are molecules that have a distinct separation between hydrophobic and hydrophilic regions.

Lounge loverd

In both cases, an external trigger leads to the exposure of an AH that inserts into the cytosolic leaflet of the membrane and is assumed to drive the fission of vesicles. Structure and dynamics of helix-0 of the N-BAR domain in lipid micelles and bilayers. Predictions and Experimental Approaches to Study Amphipathic Helices The analysis of AHs is facilitated by bioinformatics tools such as Heliquest [ 11 ] which project any amino-acid sequence onto a helical wheel and calculate various parameters such as AH hydrophobicity, charge, and hydrophobic moment an index of the amphipathic character of the putative helix. Deeper structural analysis of AHs is sometimes performed but requires more advanced approaches. We welcome feedback: report an example sentence to the Collins team. Amphipathic proteins are comprised of polar and nonpolar sequences of amino acids. The small G protein ARF1 is involved in intracellular vesicle trafficking [ 35 ]. Lee, E. How they function, or if other molecules or sources of energy intervene, is still matter of debate. The fundamental structure is a hydrophilic glycoside moiety and a hydrophobic triterpene or steroid derivative. Neck and hemifission intermediates of the membrane fission process resemble pore and hemifusion intermediates of the opposite membrane fusion process.

All living cells are surrounded by a cell membrane.

A cationic, C-terminal patch and structural rearrangements in Ebola virus matrix VP40 protein control its interactions with phosphatidylserine. See Definitions and Examples ». Protein-driven membrane stresses in fusion and fission. Identification and molecular characterization of the chloroplast targeting domain of turnip yellow mosaic virus replication proteins. The protein mutations that disrupt their oligomerization inhibit the ability of Arf1 Beck et al. Commercial-grade lecithins isolated from soybeans are widely used in foods as emulsifying agents. Lipid interaction of the C-terminus and association of the transmembrane segments facilitate atlastin-mediated homotypic endoplasmic reticulum fusion. This suggests several future applications of isoxazolidines as transcriptional regulators. Structure and dynamics of helix-0 of the N-BAR domain in lipid micelles and bilayers. Structural inhibition of dynamin-mediated membrane fission by endophilin. Besides being cofactor for fission mediated by AH-containing proteins such as epsin Kweon et al.