Read by QxMD icon Read


Shuai Gao, Man Pan, Yong Zheng, Yichao Huang, Qingyun Zheng, Demeng Sun, Lining Lu, Xiaodan Tan, Xianglong Tan, Huan Lan, Jiaxing Wang, Tian Wang, Jiawei Wang, Lei Liu
Racemic or quasi-racemic crystallography recently emerges as a useful technology for solution of the crystal structures of biomacromolecules. It remains unclear to what extent the biomacromolecules of opposite handedness can differ from each other in racemic or quasi-racemic crystallography. Here we report a finding that monomeric d-ubiquitin (Ub) has propensity to cocrystallize with different dimers, trimers, and even a tetramer of l-Ub. In these cocrystals the unconnected monomeric d-Ubs can self-assemble to form pseudomirror images of different oligomers of l-Ub...
October 21, 2016: Journal of the American Chemical Society
Nahid Shahabadi, Monireh Falsafi, Maryam Maghsudi
The interaction of anticancer drug cytarabine with calf thymus DNA (CT-DNA) was investigated in vitro under simulated physiological conditions by multispectroscopic techniques and molecular modeling study. The fluorescence spectroscopy and UV absorption spectroscopy indicated drug interacted with CT-DNA in a groove-binding mode, while the binding constant of UV-vis and the number of binding sites were 4.0 ± 0.2 × 10(4) L mol(-1) and 1.39, respectively. The fluorimetric studies showed that the reaction between the drugs with CT-DNA is exothermic...
October 19, 2016: Nucleosides, Nucleotides & Nucleic Acids
Yang Wang, Ting Li, Xuefei Wang, Piming Ma, Huiyu Bai, Weifu Dong, Yi Xie, Mingqing Chen
Melanin, a kind of well-known multifunctional biomacromolecules that are widely available in large quantities from a variety of natural sources. In this work, Polyurethane (PU) /melanin nanocomposites with enhanced tensile strength and toughness were successfully fabricated via in situ polymerization. It was found that the tensile strength (σ), elongation-at-break (εmax) and work to fracture (W) were increased from 5.6 MPa, 770% and 33 MJ/m3 for PU to 51.5 MPa, 1880% and 413 MJ/m3 for PU/melanin (2 wt %) nanocomposite, respectively...
October 17, 2016: Biomacromolecules
Ikuhiko Nakase, Kosuke Noguchi, Ikuo Fujii, Shiroh Futaki
Extracellular vesicles (EVs, exosomes) are approximately 30- to 200-nm-long vesicles that have received increased attention due to their role in cell-to-cell communication. Although EVs are highly anticipated to be a next-generation intracellular delivery tool because of their pharmaceutical advantages, including non-immunogenicity, their cellular uptake efficacy is low because of the repulsion of EVs and negatively charged cell membranes and size limitations in endocytosis. Here, we demonstrate a methodology for achieving enhanced cellular EV uptake using arginine-rich cell-penetrating peptides (CPPs) to induce active macropinocytosis...
October 17, 2016: Scientific Reports
Xiao-Peng He, Yi Zang, Tony D James, Jia Li, Guo-Rong Chen, Juan Xie
The development of small-molecule fluorescent probes for the detection of ions and biomacromolecules and for cellular and in vivo imaging has been a very active research area. Nevertheless, many problems exist for traditional probes including their poor water solubility, toxicity and the inability to target specific tissues. Because of the enhanced water solubility, biocompatibility and targeting ability for specific cells, there has been an emerging movement to use carbohydrates as either the backbone or as a warhead to decorate conventional fluorescent probes, producing "glycoprobes" with enhanced properties...
October 14, 2016: Chemical Communications: Chem Comm
Yang Song, Ulyana Shimanovich, Thomas C T Michaels, Qingming Ma, Jingmei Li, Tuomas P J Knowles, Ho Cheung Shum
All-aqueous emulsions exploit spontaneous liquid-liquid separation and due to their water-based nature are particular advantageous for the biocompatible storage and processing of biomacromolecules. However, the ultralow interfacial tensions characteristic of all-aqueous interfaces represent an inherent limitation to the use of thermally adsorbed particles to achieve emulsion stability. Here, we use protein nanofibrils to generate colloidosome-like two-dimensional crosslinked networks of nanostructures templated by all-aqueous emulsions, which we term fibrillosomes...
October 11, 2016: Nature Communications
Rui Hu, Hong-Kin Yap, Yik-Hong Fung, Yong Wang, Wing-Lam Cheong, Lok-Yan So, Chui-Shan Tsang, Lawrence Yoon Suk Lee, Warrick Ken Cheung Lo, Jian Yuan, Ning Sun, Yun-Chung Leung, Guoqiang Yang, Kwok-Yin Wong
Fluorescent labeling of biomacromolecules to 'light up' biological events through non-invasive methods is of great importance, but is still challenging in terms of fluorophore properties and the labeling methods used. Herein, we designed and synthesized a biocompatible and conformation sensitive tetraphenylethene derivative EPB with aggregation induced emission (AIE) properties. By introducing EPB into TEM-1 β-lactamase (TEM-1 Bla) through a two-step approach, a conformation-dependent fluorescent sensor EPB104-Bla was genetically engineered, which was applied to monitor the protein-protein interaction (PPI) with β-lactamase inhibitor protein (BLIP)...
October 4, 2016: Molecular BioSystems
Juan Wang, Guizhi Shen, Kai Ma, Tifeng Jiao, Kai Liu, Xuehai Yan
Concave nanospheres based on the self-assembly of simple dipeptides not only provide alternatives for modeling the interactions between biomacromolecules, but also present a range of applications for purification and separation, and delivery of active species. The kinetic control of the peptide assembly provides a unique opportunity to build functional and dynamic nanomaterials, such as concave nanospheres. In this work, we report dipeptide-based concave nanospheres with structures from crescent-like to solid interior by interfacially controlled self-assembly in combination with covalent formation of building blocks, driven by synergistic thermodynamic and kinetic control...
October 10, 2016: Physical Chemistry Chemical Physics: PCCP
S Vigneswari, V Murugaiyah, G Kaur, H P S Abdul Khalil, A A Amirul
Polyhydroxyalkanoate (PHA) is a microbial polymer that has been at the forefront of many attempts at tissue engineering. However, the surface of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) is hydrophobic with few recognition sites for cell attachment. Various concentrations of fish-scale collagen peptides (FSCPs) were incorporated into P(3HB-co-4HB) copolymer by aminolysis. Later, FSCPs were introduced onto the aminolyzed P(3HB-co-4HB) scaffolds. Introduction of the FSCP groups was verified using Fourier transform infrared spectroscopy and the ninhydrin method...
October 6, 2016: Biomedical Materials
Rui Lu, Wen-Wei Li, Abraham Katzir, Yosef Raichlin, Boris Mizaikoff, Han-Qing Yu
The secondary structure of proteins and their conformation are intimately related to their biological functions. In this study, heat-induced changes in the secondary structure and conformation of hemoglobin were investigated via infrared attenuated total reflection (IR-ATR) spectroscopy. The secondary structure changes of hemoglobin were derived from IR-ATR spectra using second derivatives and curve fitting. Thereby, the thermal denaturation temperature ranges and the secondary structure changes with temperature were revealed...
October 17, 2016: Analyst
Qiang Gao, Chao Huang, Binbin Sun, Bhutto M Aqeel, Jing Wang, Weiming Chen, Xiumei Mo, Xinjian Wan
Stent insertion and chemical agents of ethylene diamine tetraacetic acid and sodium cholate for dissolving common bile duct stone diseases through extra biliary tract infusion have been believed a relatively effective therapeutics for the clinical symptom. Core-shell nanofibers produced by co-axial electrospinning to deliver chemical drugs, biomacromolecules, genes and even cells have been reported for various advanced drug delivery system and tissue engineering applications. In the present study, poly (lactide-co-ɛ-caprolactone) (PLCL) core-shell nanofiber-coated film of stent, loaded with ethylene diamine tetraacetic acid and sodium cholate in core layer, was fabricated by co-axial electrospinning for treating gallstone disease...
October 3, 2016: Journal of Biomaterials Applications
Christian Schulz, Jochen Hecht, Anne Krüger-Genge, Karl Kratz, Friedrich Jung, Andreas Lendlein
Common strategies for biofunctionalization of surfaces comprise the immobilization of bioactive molecules used as cell-binding ligands for cell recruitment. Besides covalent binding, multivalent noncovalent physical forces between substrate and ligand are an alternative way to equip surfaces with biomacromolecules. In this study, polymer binding ligands are screened by means of a DNA-based in vitro selection process. As candidate biomaterials poly(ether imide) (PEI), polystyrene, and poly[ethylene-co-(vinyl acetate)] are selected, due to their different chemical structure, but similar macroscopic interface properties, allowing physical interaction with nucleotide bases by varying valences...
September 30, 2016: Macromolecular Bioscience
Yan Fang, Jianxiu Xue, Liyuan Ke, Yang Liu, Kai Shi
A kind of polymeric lipid vesicles (PLVs) with pH-responsive turning on-off membrane for programed delivery of insulin in gastrointestinal (GI) tract was developed, which was self-assembled from the grafted amphipathic polymer of N-tocopheryl-N'-succinyl-ɛ-poly-l-lysine (TP/SC-g-PLL). By controlling the grafting ratio of hydrophobic alkane and ionizable carboxyl branches, the permeability of membrane was adjustable and thus allowing insulin release in a GI-pH dependent manner. The effects of grafting degree of substitution (DS) on the pH-responsive behavior of the formed vesicles were confirmed by critical aggregation concentration determination, morphology and size characterization...
August 15, 2016: Drug Delivery
Guorong Shi, Yating Liu, Zijun He, Jihen Zhou
We investigate the encapsulation of bovine serum albumin (BSA) in chemical-treated and chitosan-coated yeast cells, Saccharomyces cerevisiae (S. cerevisiae), for the controlled release of BSA. The chemical treatment can sufficiently enlarge the small-sized cell-wall cavities and/or break the integrity for the entrance of BSA to the interior of yeast cells, and the additional chitosan coating can well prevent the rapid release of encapsulated BSA from the yeast-derived microcapsules. The sodium hydroxide pretreated S...
August 10, 2016: Artificial Cells, Nanomedicine, and Biotechnology
Daniel Becker, Zuzanna Kaczmarska, Christoph Arkona, Robert Schulz, Carolin Tauber, Gerhard Wolber, Rolf Hilgenfeld, Miquel Coll, Jörg Rademann
Small-molecule fragments binding to biomacromolecules can be starting points for the development of drugs, but are often difficult to detect due to low affinities. Here we present a strategy that identifies protein-binding fragments through their potential to induce the target-guided formation of covalently bound, irreversible enzyme inhibitors. A protein-binding nucleophile reacts reversibly with a bis-electrophilic warhead, thereby positioning the second electrophile in close proximity of the active site of a viral protease, resulting in the covalent de-activation of the enzyme...
2016: Nature Communications
Xi Lin, Bao Nguyen Quoc, Mathias Ulbricht
Stimuli-responsive membranes that can adjust mass transfer and interfacial properties "on demand" have drawn large interest over the last few decades. Here, we designed and prepared a novel magnetoresponsive separation membrane with remote switchable molecular sieving effect by simple one-step and scalable nonsolvent induced phase separation (NIPS) process. Specifically, poly(ether sulfone) (PES) as matrix for an anisotropic membrane, prefabricated poly(N-isopropylacrylamide) (PNIPAAm) nanogel (NG) particles as functional gates, and iron oxide magnetic nanoparticles (MNP) as localized heaters were combined in a synergistic way...
October 11, 2016: ACS Applied Materials & Interfaces
Botros B Shenoda, Seena K Ajit
Exosome-mediated signaling is important in mediating the inflammatory response. To exert their biological or pathophysiological functions in the recipient cells, exosomes deliver a diverse array of biomacromolecules including long and short coding and non-coding RNAs, proteins, and lipids. Exosomes secreted by antigen-presenting cells can confer therapeutic benefits by attenuating or stimulating the immune response. Exosomes play a crucial role in carrying and presenting functional major histocompatibility peptide complexes to modulate antigen-specific T cell responses...
2016: Clinical Medicine Insights. Pathology
Matthew A Hood, Hanna Leemreize, André Scheffel, Damien Faivre
During biomineralization, organisms control the formation and morphology of a mineral using biomacromolecules. The biomacromolecules that most strongly interact with the growing crystals frequently get occluded within. Such an observation has been recently obtained for the calcium carbonate producing coccolithophore species Pleurochrysis carterae. Coccolithophores are unicellular algae that produce calcified scales built from complex-shaped calcite crystals, termed coccoliths. It is unclear how widespread the phenomenon of biomacromolecular occlusion within calcite crystals is in calcifying haptophytes such as coccolithophores...
September 16, 2016: Journal of Structural Biology
Reinhard I Boysen, Lachlan J Schwarz, Dan V Nicolau, Milton T W Hearn
This review describes recent advances associated with the development of surface imprinting methods for the synthesis of polymeric membranes and thin films, which possess the capability to selectively and specifically recognize biomacromolecules, such as proteins and single- and double-stranded DNA, employing "epitope" or "whole molecule" approaches. Synthetic procedures to create different molecularly imprinted polymer membranes or thin films are discussed, including grafting/in situ polymerization, drop-, dip-, or spin-coating procedures, electropolymerization as well as micro-contact or stamp lithography imprinting methods...
September 12, 2016: Journal of Separation Science
Mohammad G Dekamin, Elham Kazemi, Zahra Karimi, Maryam Mohammadalipoor, M Reza Naimi-Jamal
The synergic effect of the chitosan biomacromolecule support for catalyzing of Hantzsch esters formation by CuSO4 has been demonstrated for one-pot and efficient pseudo-four-component reaction to afford a wide range of 1,4-dihydropyridine (DHP) or polyhydroquinoline (PHQ) derivatives. The desired products were simply prepared from different aldehydes, β-dicarbonyls and ammonium acetate in the presence of a low loading of chitosan supported copper(II) sulfate (CSCS) in EtOH under reflux conditions. The biodegradable CSCS catalyst was characterized by field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy analysis (EDX) methods as well as coupled plasma-atomic emission (ICP-AE) and FT-IR spectroscopy...
September 5, 2016: International Journal of Biological Macromolecules
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"