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Abhi Das, Gopinatha Suresh Kumar
Backgound: Natural aristolochia alkaloids have attracted the attention of both chemists and biologists from the stand point of their structural and pharmacological aspects. Many of the compounds isolated in this group are potent tumor inhibitors. These are divided into nitrophenanthrinic acid, phenanthrene lactams and isoquinoline alkaloids. A number of structure-activity studies have been performed on aristolochia alkaloids. Of particular interest is the molecule with the β-D-glucoside moiety that has similarity to the clinical anticancer agent daunomycin...
February 22, 2018: Mini Reviews in Medicinal Chemistry
Fu-Rong Zeng, Yang Liang, Zi-Long Li
Precise structure-property relation of a biodegradable polymer (e.g., aliphatic polyester) is anticipated only if monomer units and chiral centers are arranged in a defined primary sequence as a biomacromolecule. An emerging synthetic methodology, namely segmer assembly polymerization (SAP), is introduced in this paper to reveal the latest progress in polyester synthesis. Almost any periodic polyester envisioned can be synthesized via SAP using a programed linear or cyclic monomer. In this context, the macroscopic properties of a biodegradable polymer are fundamentally determined by microstructural information through a bottom-up approach...
February 18, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Kenji Watanabe, Takashi Ohshima
A benzylic substitution of 3-indolyl(hydroxyl)acetate derivatives with thiols proceeded specifically in the presence of amino, carboxy, and phosphate groups in weakly acidic aqueous solutions under nearly physiological condition, while no reaction occurred at pH over 7. Kinetic studies revealed that the reaction followed second-order kinetics (first-order in the reactant and first-order in thiol) in contrast with the SN 1 mechanism of common benzylic substitution of alcohols. The utility of the present method for functionalization of biomacromolecules was demonstrated using several model proteins, such as lysozyme, insulin, trypsin, and serum albumin...
February 19, 2018: Chemistry: a European Journal
Lucia Paolini, Andrea Zendrini, Annalisa Radeghieri
Extracellular vesicles (EVs) are cell-derived nanoparticles, involved in cell-to-cell communication, in both normal and pathological processes. Originating by the outward budding of the plasma membrane or released by exocytosis, they are natural cargoes for lipids, carbohydrates, proteins and nucleic acids. EV-based diagnostics promises unique advantages compared with conventional strategies involving whole body fluid analysis, including the reduction of biofluids complexity and more specific and sensitive detection of low abundance biomacromolecules...
February 14, 2018: Biomarkers in Medicine
Baiping Mao, Caixia Liu, Wenwen Zheng, Xiaoheng Li, Renshan Ge, Haifa Shen, Xiaoling Guo, Qingquan Lian, Xian Shen, Chao Li
Regenerated silk fibroin (SF) is a natural biomacromolecule with excellent biocompatible and biodegradable properties. In this study, cyclic pentapeptide cRGDfk and Chlorin e6 (Ce6) were conjugated to SF polypeptides, and genipin was used to prepare 5-fluorouracil (5-FU) doped SF-based nanoparticles (NPs). The photodynamic therapy (PDT) potential and active targeting properties were systematically investigated in αvβ3 integrin receptor over-expressed MGC-803 cells in vitro. The results revealed that treatment with the multifunctional SF-based NPs and PDT, high level of reactive oxygen species (ROS) and cell death can be induced in MGC-803 cells...
February 3, 2018: Biomaterials
Jun Ohata, Yimeng Zeng, Laura Segatori, Zachary Thomas Ball
Manipulation of biomacromolecules is ideally achieved through unique and bioorthogonal chemical reactions of genetically encoded, naturally occurring functional groups. The toolkit of methods for site-specific conjugation is limited by selectivity concerns and a dearth of naturally occurring functional groups with orthogonal reactivity. We report that pyroglutamate amide N-H bonds exhibit bioorthogonal copper-catalyzed Chan-Lam coupling at pyroglutamate-histidine dipeptide sequences. The pyroglutamate residue is readily incorporated into proteins of interest by natural enzymatic pathways, allowing specific bioconjugation at a minimalist dipeptide tag...
February 7, 2018: Angewandte Chemie
Safrina Dyah Hardiningtyas, Rie Wakabayashi, Momoko Kitaoka, Yoshiro Tahara, Kosuke Minamihata, Masahiro Goto, Noriho Kamiya
Phycocyanin (PC), a water-soluble protein-chromophore complex composed of hexameric (αβ)6 subunits, has important biological functions in blue-green algae as well as pharmacological activities in biomedicine. We have previously developed a solid-in-oil (S/O) nanodispersion method to deliver biomacromolecules through the skin, although the transcutaneous mechanism has not yet been fully elucidated. To study the mechanism of transcutaneous protein delivery, we therefore enabled S/O nanodispersion by coating PC with hydrophobic surfactants and evaluated how the proteinaceous macromolecules formulated in an oil phase might permeate the skin...
February 3, 2018: European Journal of Pharmaceutics and Biopharmaceutics
Rui Li, Natasha L Mcrae, Daniel R McCulloch, Mitchell Boyd-Moss, Colin J Barrow, David R Nisbet, Nicole Stupka, Richard J Williams
The material properties of natural tissues, such as muscle, are highly sophisticated and are synthetically challenging to mimic. Using natural biomacromolecules to functionalise self-assembled peptide (SAP) hydrogels has the potential to increase the utility of these materials by more closely reproducing the natural cellular environment. Here, to demonstrate that a conserved co-assembly pathway can retain distinct function, the low molecular weight gelator Fmoc-FRGDF was co-assembled with either a sulphated polysaccharide, fucoidan, or the basement membrane proteoglycan, versican...
February 1, 2018: Biomacromolecules
Yuichiro Hori, Norimichi Otomura, Ayuko Nishida, Miyako Nishiura, Maho Umeno, Isao Suetake, Kazuya Kikuchi
Hybrid probes consisting of synthetic molecules and proteins are powerful tools for detecting biological molecules and signals in living cells. To date, most targets of the hybrid probes have been limited to pH and small analytes. Although biomacromolecules are essential to the physiological function of cells, the hybrid-probe-based approach has been scarcely employed for live-cell detection of biomacromolecules. Here, we developed a hybrid probe with a chemical switch for live-cell imaging of methylated DNA, an important macromolecule in the repression of gene expression...
January 30, 2018: Journal of the American Chemical Society
Xiang Li, Shichang Deng, Mingliang Liu, Yan Jin, Shuai Zhu, Shijiang Deng, Jingyuan Chen, Chi He, Qi Qin, Chunyou Wang, Gang Zhao
Cancer cells predominantly produce energy at a high rate of glycolysis even in aerobic environment. It is termed as Warburg effect and is necessary for the tumorigenesis. Studies showed pyruvate kinase M2 (PKM2), a key regulator of the Warburg effect, is overexpressed and involved in numerous cancers. However, the expression and function of PKM2 in pancreatic cancer (PC) remain undefined. Our results showed that PKM2 is overexpressed in the PC tissue compared to the peritumoral tissue. Unexpected, the downregulation of PKM2 did not affect the proliferation, invasion, and chemoresistance of PC cells...
January 26, 2018: Cell Death & Disease
Sana Ahmed, Osato Miyawaki, Kazuaki Matsumura
Transportation of biomolecules into cells is of great importance in tissue engineering and as stimulation for antitumor immune cells. Previous freezing strategies at ultra-cold temperatures (-80 °C) used for intracellular transportation exhibit certain limitations such as extended time requirements and harsh delivery system conditions. Thus, the need remains to develop simplified methods for safe nanomaterial delivery. Here, we demonstrated a unique strategy based on ice crystallization-induced freeze concentration for protein intracellular delivery in combination with a polyampholyte cryoprotectant...
January 23, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Eitan Lerner, Thorben Cordes, Antonino Ingargiola, Yazan Alhadid, SangYoon Chung, Xavier Michalet, Shimon Weiss
Classical structural biology can only provide static snapshots of biomacromolecules. Single-molecule Förster resonance energy transfer (smFRET) paved the way for studying dynamics in macromolecular structures under biologically relevant conditions. Since its first implementation in 1996, smFRET experiments have confirmed previously hypothesized mechanisms and provided new insights into many fundamental biological processes, such as DNA maintenance and repair, transcription, translation, and membrane transport...
January 19, 2018: Science
Mingling Dong, Wenshu Zheng, Yiping Chen, Bei Ran, Zhiyong Qian, Xingyu Jiang
Conventional magnetic sensors usually employ Fe-based magnetic materials as signal probes. In this work, we find that Cu(II) is also a useful longitudinal relaxation time (T1) signal-based magnetic probe. We adopt bathocuproinedisulfonic acid disodium salt hydrate (BCS) to chelate Cu(I) and form a stable Cu(I)-BCS complex in aqueous solution, and find the significant difference in T1 value of water protons between Cu(II) aqueous solution and Cu(I)-BCS complex aqueous solution. Redox reaction can convert Cu(II) to Cu(I) followed by the complexation of BCS, which results in apparent change of T1 that can serve as magnetic signal readout, which is the basis of this Cu-T1 sensor...
January 18, 2018: Analytical Chemistry
Luciano Caseli
In this review we discuss about the immobilization of enzymes in Langmuir-Blodgett films in order to determine the catalytic properties of these biomacromolecules when adsorbed on solid supports. Usually, the conformation of enzymes depends on the environmental conditions imposed to them, including the chemical composition of the matrix, and the morphology and thickness of the film. In this review, we show an outline of manuscripts that report the immobilization of enzymes as LB films since the 1980's, and also some examples of how the surface properties of the floating monolayer prepared previously to the transfer to the solid support are important to determine the efficiency of the resulting device...
January 11, 2018: Anais da Academia Brasileira de Ciências
Dapeng Wang, Haichao Wu, Daniel K Schwartz
Theoretical predictions have suggested that molecular motion at interfaces-which influences processes including heterogeneous catalysis, (bio)chemical sensing, lubrication and adhesion, and nanomaterial self-assembly-may be dominated by hypothetical "hops" through the adjacent liquid phase, where a diffusing molecule readsorbs after a given hop according to a probabilistic "sticking coefficient." Here, we use three-dimensional (3D) single-molecule tracking to explicitly visualize this process for human serum albumin at solid-liquid interfaces that exert varying electrostatic interactions on the biomacromolecule...
December 29, 2017: Physical Review Letters
Luis Pérez-Mas, Alberto Martín-Molina, Manuel Quesada-Pérez, Arturo Moncho-Jordá
In this work the equilibrium absorption of nanometric cosolutes (which could represent drugs, reactants, small globular proteins and other kind of biomacromolecules) inside neutral hydrogels is studied. We specially focus on exploring, for different swelling states, the competition between the steric exclusion induced by the cross-linked polymer network constituting the hydrogel, and the solvent-induced short-range hydrophobic attraction between the polymer chains and the cosolute particle. For this purpose, the cosolute partition coefficient is calculated by means of coarse-grained grand canonical Monte Carlo simulations, and the results are compared to theoretical predictions based on the calculation of the excluded and binding volume around the polymer chains...
January 11, 2018: Physical Chemistry Chemical Physics: PCCP
Lanjunzi Liu, Xiuzhi Kang, Chao Chen, Heping Zhang, Chenpu Chen, Qingji Xie
Novel amperometric bi-enzyme biosensor based on tyrosinase (Tyr)-catalyzed L-tyrosine polymerization to effectively immobilize Tyr and glucose oxidase (GOx) simultaneously has been developed and is demonstrated to be efficient in monitoring multi-analyte (bisphenol A (BPA), phenol, Cr(III), glucose, and Cr(VI)). For the first time, the polymer from L-tyrosine oxidation (PLT) was utilized to in-situ immobilize biomacromolecules and was demonstrated to be effective in entrapping high-load and high-activity enzymes...
March 1, 2018: Talanta
Tian-Fu He, Zhi-Hong Zhang, Xin-An Zeng, Lang-Hong Wang, Charles S Brennan
This work was aimed to investigate the antibacterial action of cinnamaldehyde (CIN) against Escherichia coli ATCC 8735 (E. coli) based on membrane fatty acid composition analysis, alterations of permeability and cell morphology as well as interaction with genomic DNA. Analysis of membrane fatty acids using gas chromatography-mass spectrometry (GC-MS) revealed that the proportion of unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were the major fatty acids in plasmic membrane, and their levels were significantly changed after exposure of E...
November 10, 2017: Journal of Photochemistry and Photobiology. B, Biology
Xue-Wei Cao, Xu-Zhong Yang, Xuan Du, Long-Yun Fu, Tao-Zhu Zhang, Han-Wen Shan, Jian Zhao, Fu-Jun Wang
Cell-penetrating peptide (CPP) is used for the delivery of biomacromolecules across the cell membrane and is limited in cancer therapy due to the lack of cell selectivity. Epidermal growth factor receptor (EGFR) has been widely used in clinical targeted therapy for tumors. Here we reported a novel tumor targeting cell-penetrating peptide (TCPP), EHB (ELBD-C6H) with 20-fold and 3000-fold greater transmembrane ability and tumor cell selectivity than our previously reported S3-HBD and classic CPP TAT, respectively...
January 5, 2018: Journal of Drug Targeting
Anees A Ansari, Ali Aldalbahi, Joselito P Labis, Ahmed Mohamed El-Toni, Maqusood Ahamed, M Aslam Manthrammel
Monodispersed La(OH)3:Eu nanospheres(core-NSs) were synthesized by urea-based homogeneous co-precipitation process, where mesoporous silica layer was coated over the surface of luminescent La(OH)3:Eu core-NSs. The XRD data exhibit the high crystalline, single hexagonal-shaped La(OH)3:Eu core and silica modified La(OH)3:Eu@mSiO2 (core-shell) NSs. Monodispersibility, spherical shaped, high surface area and mesoporosity were identified by TEM analysis and were further confirmed by BET analysis. The as-synthesized samples are highly soluble in aqueous media at ambient conditions...
December 16, 2017: Colloids and Surfaces. B, Biointerfaces
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