544-77-4Relevant articles and documents
Lipid modifications of a ras peptide exhibit altered packing and mobility versus host membrane as detected by2H solid-state NMR
Vogel, Alexander,Katzka, Catherine P.,Waldmann, Herbert,Arnold, Klaus,Brown, Michael F.,Huster, Daniel
, p. 12263 - 12272 (2005)
The human N-ras protein binds to cellular membranes by insertion of two covalently bound posttranslational lipid modifications, which is crucial for its function in signal transduction and cell proliferation. Mutations in ras may lead to unregulated cell growth and eventually cancer, making it an important therapeutic target. Here we have investigated the molecular details of the membrane binding mechanism. A heptapeptide derived from the C-terminus of the human N-ras protein was synthesized including two hexadecyl modifications. Solid-state 2H NMR was used to determine the packing and molecular dynamics of the ras lipid chains as well as the phospholipid matrix. Separately labeling the chains of the peptide and the phospholipids with 2H enabled us to obtain atomically resolved parameters relevant to their structural dynamics. While the presence of ras only marginally affected the packing of DMPC membranes, dramatically lower order parameters (SCD) were observed for the ras acyl chains indicating modified packing properties. Essentially identical projected lengths of the 16:0 ras chains and the 14:0 DMPC chains were found, implying that the polypeptide backbone is located at the lipid-water interface. Dynamical properties of both the ras and phospholipid chains were determined from spin-lattice 2H relaxation (R 1Z) measurements. Plots of R1Z rates versus the corresponding squared segmental order parameters revealed striking differences. We propose the ras peptide is confined to microdomains containing DMPC chains which are in exchange with the bulk bilayer on the 2H NMR time scale (～10-5 s). Compared to the host DMPC matrix, the ras lipid modifications are extremely flexible and undergo relatively large amplitude motions. It is hypothesized that this flexibility is a requirement for the optimal anchoring of lipid-modified proteins to cellular membranes.
Elongation of the Hydrophobic Chain as a Molecular Switch: Discovery of Capsaicin Derivatives and Endogenous Lipids as Potent Transient Receptor Potential Vanilloid Channel 2 Antagonists
Schiano Moriello, Aniello,López Chinarro, Silvia,Novo Fernández, Olalla,Eras, Jordi,Amodeo, Pietro,Canela-Garayoa, Ramon,Vitale, Rosa Maria,Di Marzo, Vincenzo,De Petrocellis, Luciano
, p. 8255 - 8281 (2018/09/25)
The transient receptor potential vanilloid type-2 (TRPV2) protein is a nonselective Ca2+ permeable channel member of the TRPV subfamily, still considered an orphan TRP channel due to the scarcity of available selective and potent pharmacological tools and endogenous modulators. Here we describe the discovery of novel synthetic long-chain capsaicin derivatives as potent TRPV2 antagonists in comparison to the totally inactive capsaicin, the role of their hydrophobic chain, and how the structure-activity relationships of such derivatives led, through a ligand-based approach, to the identification of endogenous long-chain fatty acid ethanolamides or primary amides acting as TRPV2 antagonists. Both synthetic and endogenous antagonists exhibited differential inhibition against known TRPV2 agonists characterized by distinct kinetic profiles. These findings represent the first example of both synthetic and naturally occurring TRPV2 modulators with efficacy in the submicromolar/low-micromolar range, which will be useful for clarifying the physiopathological roles of this receptor, its regulation, and its targeting in pathological conditions.
A mild and highly chemoselective iodination of alcohol using polymer supported DMAP
Das, Diparjun,H Anal, Jasha Momo,Rokhum, Lalthazuala
, p. 1695 - 1701 (2017/03/08)
The synthesis of organic compounds using polymer supported catalysts and reagents, where the required product is always in solution, has been of great interest in recent years, both in industries and academia especially in pharmaceutical research. Here, a simple and efficient method for conversion of alcohols into their iodides in high yield using polymer supported 4-(Dimethylamino)pyridine (DMAP) is described. Polymer supported DMAP is used in catalytic amount and is recovered and reused several times. Additionally, this method is highly chemoselective. [Figure not available: see fulltext.]
