9 research outputs found
Quantum confined peptide assemblies with tunable visible to near-infrared spectral range
Quantum confined materials have been extensively studied for photoluminescent applications. Due to intrinsic limitations of low biocompatibility and challenging modulation, the utilization of conventional inorganic quantum confined photoluminescent materials in bio-imaging and bio-machine interface faces critical restrictions. Here, we present aromatic cyclo-dipeptides that dimerize into quantum dots, which serve as building blocks to further self-assemble into quantum confined supramolecular structures with diverse morphologies and photoluminescence properties. Especially, the emission can be tuned from the visible region to the near-infrared region (420 nm to 820 nm) by modulating the self-assembly process. Moreover, no obvious cytotoxic effect is observed for these nanostructures, and their utilization for in vivo imaging and as phosphors for light-emitting diodes is demonstrated. The data reveal that the morphologies and optical properties of the aromatic cyclo-dipeptide self-assemblies can be tuned, making them potential candidates for supramolecular quantum confined materials providing biocompatible alternatives for broad biomedical and opto-electric applications
Alkyl Group Dependence of the Surface-Induced Assembly of Nonionic Disaccharide Surfactants
Novel Nonionic Oligosaccharide Surfactant Polymers Derived from Poly(vinylamine) with Pendant Dextran and Hexanoyl Groups
Dual X-ray absorptiometry of the proximal femur: normal European values standardised with the European spine phantom
Structural, Chemical, and Mechanical Properties of Pressure Garments as a Function of Simulated Use and Repeated Laundering
Evidence that a threshold of serine/arginine-rich (SR) proteins recruits CFIm to promote rous sarcoma virus mRNA 3′ end formation
The Unfolded Protein Response Transducer Ire1p Contains a Nuclear Localization Sequence Recognized by Multiple β Importins
The Ire1p transmembrane receptor kinase/endonuclease transduces the unfolded protein response (UPR) from the endoplasmic reticulum (ER) to the nucleus in Saccharomyces cerevisiae. In this study, we analyzed the capacity of a highly basic sequence in the linker region of Ire1p to function as a nuclear localization sequence (NLS) both in vivo and in vitro. This 18-residue sequence is capable of targeting green fluorescent protein to the nucleus of yeast cells in a process requiring proteins involved in the Ran GTPase cycle that facilitates nuclear import. Mutagenic analysis and importin binding studies demonstrate that the Ire1p linker region contains overlapping potential NLSs: at least one classical NLS (within sequences (642)KKKRKR(647) and/or (653)KKGR(656)) that is recognized by yeast importin α (Kap60p) and a novel βNLS ((646)KRGSRGGKKGRK(657)) that is recognized by several yeast importin β homologues. Kinetic binding data suggest that binding to importin β proteins would predominate in vivo. The UPR, and in particular ER stress-induced HAC1 mRNA splicing, is inhibited by point mutations in the Ire1p NLS that inhibit nuclear localization and also requires functional RanGAP and Ran GEF proteins. The NLS-dependent nuclear localization of Ire1p would thus seem to be central to its role in UPR signaling