| 1. |
- Chen, Zhiliang, et al.
(author)
-
Synergistic Catalysis by “Polymeric Microzymes and Inorganic Nanozymes” : The 1+1>2 Effect for Intramolecular Cyclization of Peptides
- 2017
-
In: Frontiers in Chemistry. - : Frontiers Media S.A.. - 2296-2646. ; 5
-
Journal article (peer-reviewed)abstract
- In this work, we developed an efficient “molecularly imprinted polymer microzymes and inorganic magnetic nanozymes” synergistic catalysis strategy for the formation of disulfide bonds in peptides. The polymeric microzymes showed excellent selectivity toward the template peptide as well as the main reactant (linear peptide), and the Fe3O4 magnetic nanoparticle (MNP) nanozymes inhibited the intermolecular reaction during the formation of disulfide bonds in peptides. As a result, the integration of the two different artificial enzymes in one process facilitates the intramolecular cyclization in high product yields (59.3%) with excellent selectivity. Mechanism study indicates the synergistic effect was occurred by using a “reversed solid phase synthesis” strategy with an enhanced shift of reaction balance to product generation. We believe the synergistic catalysis by “polymeric microzymes and inorganic nanozymes” presented in the present work may open new opportunities in creation of multifunctional enzyme mimics for sensing, imaging, and drug delivery.
|
|
| 2. |
- Hellinger, Roland, et al.
(author)
-
Chemical Proteomics for Target Discovery of Head-to-Tail Cyclized Mini-Proteins
- 2017
-
In: Frontiers in Chemistry. - : FRONTIERS MEDIA SA. - 2296-2646. ; 5
-
Journal article (peer-reviewed)abstract
- Target deconvolution is one of the most challenging tasks in drug discovery, but a key step in drug development. In contrast to small molecules, there is a lack of validated and robust methodologies for target elucidation of peptides. In particular, it is difficult to apply these methods to cyclic and cysteine-stabilized peptides since they exhibit reduced amenability to chemical modification and affinity capture; however, such ribosomally synthesized and post-translationally modified peptide natural products are rich sources of promising drug candidates. For example, plant-derived circular peptides called cyclotides have recently attracted much attention due to their immunosuppressive effects and oral activity in the treatment of multiple sclerosis in mice, but their molecular target has hitherto not been reported. In this study, a chemical proteomics approach using photo-affinity crosslinking was developed to determine a target for the circular peptide [T20K]kalata B1. Using this prototypic nature-derived peptide enabled the identification of a possible functional modulation of 14-3-3 proteins. This biochemical interaction was validated via competition pull down assays as well as a cellular reporter assay indicating an effect on 14-3-3-dependent transcriptional activity. As proof of concept, the presented approach may be applicable for target elucidation of various cyclic peptides and mini-proteins, in particular cyclotides, which represent a promising class of molecules in drug discovery and development.
|
|
| 3. |
- Kamran, Muhammad, et al.
(author)
-
Hydroquinone; a novel bioactive compound from plant-derived smoke can cue seed germination of lettuce
- 2017
-
In: Frontiers in Chemistry. - : Frontiers Media S.A.. - 2296-2646. ; 5
-
Journal article (peer-reviewed)abstract
- Plant-derived smoke has been known to play an important role in distribution and growth of vegetation. Using a proficiently designed furnace, we extracted smoke from the leaves of four plant viz. Helianthus annuus,Aloe vera,Ginkgo biloba, and Cymbopogon jwarancusa. Smoke dilutions obtained from these plants were obtained in different concentrations to identify potential lettuce growth promoting smoke solution. Results revealed that smoke obtained from G. biloba significantly enhanced the lettuce seed germination. This solution was then partitioned into ethyl acetate, dichloromethane, n-hexane, chloroform and ether fractions. Ethyl acetate fraction was found to be potent to enhance seed germination. This fraction was subjected to column chromatography and spectroscopic techniques to obtain compound 1. This compound was identified as hydroquinone using 1D and 2D NMR techniques. At low concentrations (5, 10, and 20 ppm), compound 1 enhanced the lettuce seed germination; however, higher concentrations inhibited its growth as compared to control.
|
|
| 4. |
- Weser, Oskar, et al.
(author)
-
In Search of the reason for the breathing effect of MIL53 metal-organic framework : An ab initio multiconfigurational study
- 2017
-
In: Frontiers in Chemistry. - : Frontiers Media SA. - 2296-2646. ; 5:DEC
-
Journal article (peer-reviewed)abstract
- Multiconfigurational methods are applied to study electronic properties and structural changes in the highly flexible metal-organic framework MIL53(Cr). Via calculated bending potentials of angles, that change the most during phase transition, it is verified that the high flexibility of this material is not a question about special electronic properties in the coordination chemistry, but about overall linking of the framework. The complex posseses a demanding electronic structure with delocalized spin density, antifferomagnetic coupling and high multi-state character requiring multiconfigurational methods. Calculated properties are in good agreement with known experimental values confirming our chosen methods.
|
|
| 5. |
- Öberg, Elisabet, et al.
(author)
-
Non-fused Phospholes as Fluorescent Probes for Imaging of Lipid Droplets in Living Cells
- 2017
-
In: Frontiers in Chemistry. - : FRONTIERS MEDIA SA. - 2296-2646. ; 5
-
Journal article (peer-reviewed)abstract
- Molecular tools for fluorescent imaging of specific compartments in cells are essential for understanding the function and activity of cells. Here, we report the synthesis of a series of pyridyl- and thienyl-substituted phospholes and the evaluation of these dyes for fluorescent imaging of cells. The thienyl-substituted phospholes proved to be successful for staining of cultured normal and malignant cells due to their fluorescent properties and low toxicity. Co-staining experiments demonstrated that these probes target lipid droplets, which are, lipid-storage organelles found in the cytosol of nearly all cell types. Our findings confirm that thienyl-substituted phospholes can be utilized as fluorescent tools for vital staining of cells, and we foresee that these fluorescent dyes might be used in studies to unravel the roles that lipid droplets play in cellular physiology and in diseases.
|
|
