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Qi Wang, Chun Zhang, Fangxia Guo, Zenglan Li, Yong Dong Liu, Zhiguo Su
In this paper, we reported a novel strategy for site specific PEGylation of proteins using elevated hydrostatic pressure. The process was similar to the conventional one except the reactor was under elevated hydrostatic pressure. The model protein was recombinant human ciliary neurotrophic factor (rhCNTF), and the reagent was mono-methoxy-polyethylene glycol-maleimide (mPEG-MAL). PEGylation with mPEG-40kDa-MAL at pH 7.0 under normal pressure for 5 hours achieved less than 5% yield. In comparison, when the pressure was elevated, the PEGylation yield was increased dramatically, reaching nearly 90% at 250 MPa...
October 20, 2017: Bioconjugate Chemistry
Pavel Dyakonov, Kirill Mironovich, Sergey Svyakhovskiy, Olga Voloshina, Sarkis Dagesyan, Andrey Panchishin, Nikolay Suetin, Victor Bagratashvili, Petr Timashev, Evgeny Shirshin, Stanislav Evlashin
Herein we report about developing new type of Surface Enhanced Raman Scattering (SERS) substrates based on Au-decorated carbon nanowalls. The designed substrates possess high specific surface area and high sensitivity. Chemical stability of Au perfectly blends with electrical properties and high value of specific surface area of carbon nanowalls. Created structures were applied to detect signals of a typical molecule used for SERS substrates testing, rhodamine 6G, which exhibits electronic absorption in the visible area of spectrum, and biomacromolecules such as tryptophan, guanine, bovine serum albumin and keratin hydrolysates, whose electronic absorption is in the ultraviolet region of spectrum and lies far from the Au plasmonic resonance...
October 17, 2017: Scientific Reports
Jacques Rigo, Catherine Pieltain, Viola Christmann, Francesco Bonsante, Sissel J Moltu, Silvia Iacobelli, Stéphane Marret
Magnesium (Mg) is an essential mineral in the body, impacting the synthesis of biomacromolecules, bone matrix development, energy production, as well as heart, nerve, and muscle function. Although the importance of Mg is evident, reference values for serum Mg (sMg) in pediatric patients (more specifically, in neonates) are not well established. This systematic literature review and meta-analysis (using 47 eligible studies) aims to quantify normal and tolerable ranges of sMg concentrations during the neonatal period and to highlight the factors influencing Mg levels and the importance of regulating sMg levels during pregnancy and birth...
October 16, 2017: Nutrients
Lina Liu, Dongyue Su, Xiaoman Liu, Lei Wang, Jie Zhan, Hui Xie, Xianghe Meng, Hao Zhang, Jian Liu, Xin Huang
An effective method to modulate the permeability of microcapsules on demand based on a "self-sacrificing" strategy was demonstrated, which then realized a programmed release of the corresponding loaded biomacromolecules.
October 11, 2017: Chemical Communications: Chem Comm
Zhangjian Huang, Yi Mou, Xiaojun Xu, Di Zhao, Yisheng Lai, Yuwen Xu, Cen Chen, Ping Li, Sixun Peng, Jide Tian, Yihua Zhang
Currently, no effective and safe medicines are available to treat diabetic nephropathy (DN). Bardoxolone methyl (CDDO-Me) has displayed promising anti-DN activity but serious side-effects in the clinical trial, probably because the highly reactive α-cyano-α,β-unsaturated ketone (CUK) in ring A of CDDO-Me can covalently bind to thiol functionalities in many biomacromolecules. In this study, we designed and synthesized a γ-glutamyl transpeptidase (GGT)-based and CUK-modified derivative 2 of CDDO-Me to address this issue...
October 10, 2017: Journal of Medicinal Chemistry
Andrej Berg, Christine Peter, Karen Johnston
The structure and dynamics of water at gold surfaces is important for a variety of applications, including lab on a chip and electrowetting. Classical molecular dynamics (MD) simulations are frequently used to investigate systems with water-gold interfaces, such as biomacromolecules in gold nanoparticle dispersions, but the accuracy of the simulations depends on the suitability of the force field. Density functional theory (DFT) calculations of a water molecule on gold were used as a benchmark to assess force field accuracy...
October 9, 2017: Journal of Chemical Theory and Computation
Keitaro Yamashita, Naoyuki Kuwabara, Takanori Nakane, Tomohiro Murai, Eiichi Mizohata, Michihiro Sugahara, Dongqing Pan, Tetsuya Masuda, Mamoru Suzuki, Tomomi Sato, Atsushi Kodan, Tomohiro Yamaguchi, Eriko Nango, Tomoyuki Tanaka, Kensuke Tono, Yasumasa Joti, Takashi Kameshima, Takaki Hatsui, Makina Yabashi, Hiroshi Manya, Tamao Endo, Ryuichi Kato, Toshiya Senda, Hiroaki Kato, So Iwata, Hideo Ago, Masaki Yamamoto, Fumiaki Yumoto, Toru Nakatsu
Serial femtosecond crystallography (SFX) using X-ray free-electron lasers (XFELs) holds enormous potential for the structure determination of proteins for which it is difficult to produce large and high-quality crystals. SFX has been applied to various systems, but rarely to proteins that have previously unknown structures. Consequently, the majority of previously obtained SFX structures have been solved by the molecular replacement method. To facilitate protein structure determination by SFX, it is essential to establish phasing methods that work efficiently for SFX...
September 1, 2017: IUCrJ
Wenwen Luo, Han Nie, Bairong He, Zujin Zhao, Qian Peng, Ben Zhong Tang
Through-space conjugation is an important non-covalent interaction in artificial materials and biomacromolecules. Establishing the relationship between the geometry and property is of high significance to deepen insights into through-space conjugation. In this work, we focus on the through-space conjugation in a new kind of foldamers with a folded tetraphenylethene kernel and study its impact on the photophysical properties by experimental measurements and theoretical calculations. It is found that the through-space conjugation makes significant contributions to the short wavelength absorption in these foldamers...
October 6, 2017: Chemistry: a European Journal
Prashant Sharma, Hyun Ah Cho, Jae-Won Lee, Woo Seung Ham, Bum Chul Park, Nam-Hyuk Cho, Young Keun Kim
Zinc oxide (ZnO) nanocomposites have been widely applied in biomedical fields due to their multifunctionality and biocompatibility. However, the physicochemical properties of ZnO nanocomposite involved in nano-bio interactions are poorly defined. To assess the potential applicability of ZnO nanowires for intracellular delivery of biomolecules, we examined the dynamics of cellular activity of cells growing on densely packed ZnO nanowire arrays with two different physical conformations, vertical (VNW) or fan-shaped (FNW) nanowires...
October 19, 2017: Nanoscale
Sandra Mitić, Marc J F Strampraad, Wilfred R Hagen, Simon de Vries
To afford mechanistic studies in enzyme kinetics and protein folding in the microsecond time domain we have developed a continuous-flow microsecond time-scale mixing instrument with an unprecedented dead-time of 3.8 ± 0.3 μs. The instrument employs a micro-mixer with a mixing time of 2.7 μs integrated with a 30 mm long flow-cell of 109 μm optical path length constructed from two parallel sheets of silver foil; it produces ultraviolet-visible spectra that are linear in absorbance up to 3.5 with a spectral resolution of 0...
2017: PloS One
Noah Al Nakeeb, Jochen Willersinn, Bernhard V K J Schmidt
The self-assembly of a novel double hydrophilic block copolymer (DHBC) architecture is presented. By combining linear biomacromolecule pullulan with biocompatible poly(oligo(ethylene glycol) methyl ether) methacrylate) (P(OEGMA))-brush blocks via copper(I) catalyzed azide alkyne cycloaddition, a novel DHBC linear-brush combination is obtained. Self-assembly in water was observed via optical microscopy and dynamic light scattering (DLS). Moreover, DLS investigations showed that self-assembly efficiency significantly relies on the degree of polymerization of the brush-block...
October 5, 2017: Biomacromolecules
Peize Liu, Zhen Chen, Lijie Yang, Qingbiao Li, Ning He
BACKGROUND: Polysaccharides and poly-γ-glutamic acid (γ-PGA) are biomacromolecules that have been reported as bioflocculants, and they exhibit high flocculating activity in many industrial applications. Bacillus licheniformis CGMCC 2876 can produce polysaccharide and γ-PGA bioflocculants under different culture conditions. Several key genes are involved in the metabolic pathway of polysaccharides in B. licheniformis, but the impacts of the regulation of these genes on the production of polysaccharide bioflocculants have not been illustrated completely...
September 26, 2017: Microbial Cell Factories
Feng Ji, Dong Men, Dianbing Wang, Xian-En Zhang
There are various nanostructures in biological system. They are made of biological molecules via self-assembly with well-organized architectures and specific functions. These nanostructures can be grouped into lines, layers and cages, corresponding to one-, two- and three-dimensional structures, respectively. The bionanostructures can serve as the models or templates for biosynthesis of biodevices with desired functions by rational design. Proof-of-concept studies have shown their attractive performance in practical applications, e...
March 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Zhengzhi Zou, Haocai Chang, Haolong Li, Songmao Wang
Reactive oxygen species (ROS), a group of ions and molecules, include hydroxyl radicals (·OH), alkoxyl radicals, superoxide anion (O2·-), singlet oxygen ((1)O2) and hydrogen peroxide (H2O2). Hydroxyl radicals and alkoxyl radicals are extremely and highly reactive species respectively. Endogenous ROS are mainly formed in mitochondrial respiratory chain. Low levels of ROS play important roles in regulating biological functions in mammalian cells. However, excess production of ROS can induce cell death by oxidative damaging effects to intracellular biomacromolecules...
September 21, 2017: Apoptosis: An International Journal on Programmed Cell Death
Pier Mario Biava, Fabio Burigana, Roberto Germano, Philip Kurian, Claudio Verzegnassi, Giuseppe Vitiello
A long history of research has pursued the use of embryonic factors isolated during cell differentiation processes for the express purpose of transforming cancer cells back to healthy phenotypes. Recent results have clarified that the substances present at different stages of cell differentiation-which we call stem cell differentiation stage factors (SCDSFs)-are proteins with low molecular weight and nucleic acids that regulate genomic expression. The present review summarizes how these substances, taken at different stages of cellular maturation, are able to retard proliferation of many human tumor cell lines and thereby reprogram cancer cells to healthy phenotypes...
September 20, 2017: Current Medicinal Chemistry
Guillaume Van der Rest, Frédéric Halgand
Noncovalent interactions are essential for the structural organization of biomacromolecules in cells. For this reason, the study of the biophysical, dynamic, and architectural interactions among biomacromolecules is essential. Since mass spectrometry requires compatible solutions while preserving the noncovalent bonding network, we envisioned that size exclusion chromatography coupled with ion mobility and mass spectrometry would be a valuable technique to desalt the initial sample and provide solution and gas-phase structural information in a single stage experiment...
November 2017: Journal of the American Society for Mass Spectrometry
Kuan Jiang, Xin Gao, Qing Shen, Changyou Zhan, Yanyu Zhang, Cao Xie, Gang Wei, Weiyue Lu
Delivery of biomacromolecules into the eye is greatly hindered by several protective barriers. The cell-penetrating peptide, penetratin, has been found to be an effective absorption enhancer for noninvasive intraocular gene delivery. To discern the composition of penetratin for safe penetration from cornea to retina, we designed a series of penetratin derivatives by varying the hydrophobicity and evaluated their potency for retina-targeted delivery. The hydrophilic amino acids of penetratin, excluding the conserved basic amino acid residues, were respectively replaced with tryptophan...
September 18, 2017: Acta Biomaterialia
Elena Piletska, Heersh Yawer, Francesco Canfarotta, Ewa Moczko, Katarzyna Smolinska-Kempisty, Stanislav S Piletsky, Antonio Guerreiro, Michael J Whitcombe, Sergey A Piletsky
Herein we describe the preparation of molecularly imprinted silica nanoparticles by Ostwald ripening in the presence of molecular templates immobilised on glass beads (the solid-phase). To achieve this, a seed material (12 nm diameter silica nanoparticles) was incubated in phosphate buffer in the presence of the solid-phase. Phosphate ions act as a catalyst in the ripening process which is driven by differences in surface energy between particles of different size, leading to the preferential growth of larger particles...
September 14, 2017: Scientific Reports
Johanna Moratz, Lucas Stricker, Sabrina Engel, Bart Jan Ravoo
An effective and universal method for delivering structurally diverse biomolecules in vivo would greatly benefit modern drug therapy, but has yet to be discovered. Self-assembled supramolecular complexes containing vesicles of amphiphilic cyclodextrin and linker molecules with an azobenzene guest unit and a charged functionality have been established as nanoscale carriers for proteins and DNA, making use of multivalent electrostatic attraction. However, light-induced cargo release is only feasible up to a maximum net charge of the biomacromolecules...
September 12, 2017: Macromolecular Rapid Communications
Adrian Moreno, Diego Garcia, Marina Galià, Joan C Ronda, Virginia Cádiz, Gerard Lligadas, Virgil Percec
Ethyl lactate (EtLa), a green and safe agrochemical solvent, is gifted with some properties that make it a good candidate for SET-LRP. It dissolves CuBr2, mediates an efficient disproportionation of CuBr in the presence of tris(2-(dimethylamino)ethyl)amine (Me6-TREN), and is capable to dissolve both aqueous (polar) and hydrocarbon (nonpolar) soluble monomers and polymers. Here, we report that EtLa is an excellent solvent for the Cu(0) wire-catalyzed SET-LRP to produce both hydrophilic and hydrophobic polyacrylates that exhibit precise chain end functionality...
September 27, 2017: Biomacromolecules
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