103 research outputs found
NMR Structure and CD Titration with Metal Cations of Human Prion α2-Helix-Related Peptides
The 173â195 segment corresponding to the helix 2 of the C-globular prion protein domain could be one of several âspotsâ of intrinsic conformational flexibility. In fact, it possesses chameleon conformational behaviour and gathers several disease-associated point mutations. We have performed spectroscopic studies on the wild-type fragment 173â195 and on its D178N mutant dissolved in trifluoroethanol to mimic the in vivo system, both in the presence and in the absence of metal cations. NMR data showed that the structure of the D178N mutant is characterized by two short helices separated by a kink, whereas the wild-type peptide is fully helical. Both peptides retained these structural organizations, as monitored by CD, in the presence of metal cations. NMR spectra were however not in favour of the formation of definite ion-peptide complexes. This agrees with previous evidence that other regions of the prion protein are likely the natural target of metal cation binding
Light spectra of biophilic LED-sourced system modify essential oils composition and plant morphology of Mentha piperita L. and Ocimum basilicum L
Investigating morphological and molecular mechanisms that plants adopt in response to artificial biophilic lighting is crucial for implementing biophilic approaches in indoor environments. Also, studying the essential oils (EOs) composition in aromatic plants can help unveil the light influence on plant metabolism and open new investigative routes devoted to producing valuable molecules for human health and commercial applications. We assessed the growth performance and the EOs composition of Mentha x piperita and Ocimum basilicum grown under an innovative artificial biophilic lighting system (CoeLuxÂź), that enables the simulation of natural sunlight with a realistic sun
perception, and compared it to high-pressure sodium lamps (control) We found that plants grown under the CoeLuxÂź light type experienced a general suppression of both above and belowground biomass, a high leaf area, and a lower leaf thickness, which might be related to the shade avoidance syndrome. The secondary metabolites composition in the plantsâ essential oils was scarcely affected by both light intensity and spectral composition of the CoeLuxÂź light type, as similarities above 80% were observed with respect to the control light treatments and within both plant species. The major differences were detected with respect to the EOs extracted from plants grown under natural sunlight (52% similarity in M. piperita and 75% in O. basilicum). Overall, it can be speculated that the growth of these two aromatic plants under the CoeLuxÂź lighting systems is a feasible strategy to improve biophilic approaches in closed environments that include both plants and artificial sunlight. Among the two plant species analyzed, O. basilicum showed an overall better performance in terms of both
morphological traits and essential oil composition. To increase biomass production and enhance the EOs quality (e.g., higher menthol concentrations), further studies should focus on technical solutions to raise the light intensity irradiating plants during their growth under the CoeLuxÂź lighting systems
GC-MS analysis of the essential oils of Juniperus communis L. berries growing wild in the Molise region: Seasonal variability and in vitro antifungal activity
Structural determinants of unexpected agonist activity in a retroâpeptide analogue of the SDFâ1α Nâterminus
We have synthesised two retroâpeptide analogues of the stromal cell derived growth factor 1 (SDFâ1α) segment known to be critical for CXCR4 receptor binding, corresponding to the sequences HSEFFRCPCRFFESH and HSEFFRGGGRFFESH. We have assayed the ability of these peptides to activate extracellular signalâregulated kinase 1/2 phosphorylation in cells over expressing the SDFâ1α receptor, finding that the first variant was able to serve as an agonist of CXCR4, whereas the second one was inactive. Finally, by comparing representative solution structures of the two peptides, we have found that the biological response of HSEFFRCPCRFFESH may be ascribed to a ÎČâÎČâtype turn motif centred on Phe4âPhe5
Synthesys, Biological Activity and Conformational analysis of [pGlu6, N-Me-Phe8, Aib9]Substance P(6-11): a selective agonist for the NK3 receptor
Proton assignment and secondary structure of p-MNEI, a single chain sweet protein related to monellin.
Structural determinants of protein translocation in bacteria: conformational flexibility of SecA IRA1 loop region
Kissper, a kiwi fruit peptide with channel-like activity: Structural and functional features
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