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Anasua Mukhopadhayay, Tarasankar Das, Anindya Datta, Kamendra P Sharma
Solvents particularly those having low-volatility are of great interest for the biocatalytic synthesis of utility chemicals and fuels. Here we show novel and universal solvent-like properties of a neat and water-less polymer surfactant-BSA conjugated material (WL-PSpBSA). This highly viscous, non-volatile material, behaves as a liquid above its solid-liquid transition temperature (≈ 25-27 °C), and can be used as a solvent for variety of completely dry solutes of different sizes, and surface chemistries. We show using a combination of optical microscopy, steady state and time-resolved fluoresence spectroscopy, that dry and powdered dyes (hydrophobic Coumarin 153; C153), enzymes (α-chymotrypsin; α-Chy), or even 2 μm microparticles (diffusion coefficient ca...
February 16, 2018: Biomacromolecules
Lingxia Wu, Xianbo Lu, Dhanjai, Zhong-Shuai Wu, Yanfeng Dong, Xiaohui Wang, Shuanghao Zheng, Jiping Chen
MXene-Ti 3 C 2 , as a new class of two-dimensional (2D) transition metal carbides (or nitrides), has been synthesized by exfoliating pristine Ti 3 AlC 2 phases with hydrofluoric acid. The SEM and XRD images show that the resultant MXene possesses a graphene-like 2D nanostructure. and the surface of MXene has been partially terminated with -OH, thus providing a favorable microenvironment for enzyme immobilization and retaining their bioactivity and stability. Considering the unique metallic conductivity, biocompatibility and good dispersion in aqueous phase, the as-prepared MXene was explored as a new matrix to immobilize tyrosinase (a model enzyme) for fabricating a mediator-free biosensor for ultrasensitive and rapid detection of phenol...
February 8, 2018: Biosensors & Bioelectronics
Kalpana Nagpal, Anand Mohan, Sourav Thakur, Pradeep Kumar
Dendrimers, commonly referred to as polymeric trees, offer endless opportunities for biotechnological and biomedical applications. By controlling the type, length, and molecular weight of the core, branches and end groups, respectively, the chemical functionality and topology of dendrimeric archetypes can be customized which further can be applied to achieve required solubility, biodegradability, diagnosis and other applications. Given the physicochemical variability of the dendrimers and their hybrids, this review attempts to discuss a full spectrum of recent advances and strides made by these "perfectly designed structures"...
February 15, 2018: Artificial Cells, Nanomedicine, and Biotechnology
Takuya Yamaguchi, Aem Nuylert, Atsutoshi Ina, Tsutomu Tanabe, Yasuhisa Asano
Hydroxynitrile lyases (HNLs), which are key enzymes in cyanogenesis, catalyze the cleavage of cyanohydrins into carbonyl compounds and hydrogen cyanide. Since HNLs also catalyze the reverse reaction, they are used industrially for the asymmetric synthesis of cyanohydrins, which are valuable building blocks of pharmaceuticals and fine chemicals. HNLs have been isolated from cyanogenic plants and bacteria. Recently, an HNL from the cyanogenic millipede Chamberlinius hualienensis was shown to have the highest specific activity for (R)-mandelonitrile synthesis, along with high stability and enantioselectivity...
February 14, 2018: Scientific Reports
Lawrence P Wackett
No abstract text is available yet for this article.
March 2018: Microbial Biotechnology
Beom Jin Kim, Hyeoncheol Cho, Ji Hun Park, João F Mano, Insung S Choi
Single-cell nanoencapsulation, forming cell-in-shell structures, provides chemical tools for endowing living cells, in a programmed fashion, with exogenous properties that are neither innate nor naturally achievable, such as cascade organic-catalysis, UV filtration, immunogenic shielding, and enhanced tolerance in vitro against lethal factors in real-life settings. Recent advances in the field make it possible to further fine-tune the physicochemical properties of the artificial shells encasing individual living cells, including on-demand degradability and reconfigurability...
February 14, 2018: Advanced Materials
Daniel Grajales, Juan Carlos Mateos, Daniel Padro, Pedro Ramos-Cabrer, Fernando López-Gallego
Protein immobilization is a key enabling technology for flow biocatalysis. For this purpose, many different immobilization protocols and characterization techniques have been developed in recent decades. However, examples where proteins are directly immobilized on ready-to-use reactors are scarce, likely due to the lack of analytical tools to monitor in-flow protein immobilization in a non-invasive manner. Here, we have for the first time exploited Magnetic Resonance Imaging (MRI) to characterize in-flow protein immobilization on pre-packed bed columns...
February 10, 2018: New Biotechnology
Monika Serafin-Lewańczuk, Magdalena Klimek-Ochab, Małgorzata Brzezińska-Rodak, Ewa Żymańczyk-Duda
Chiral hydroxyphosphonates due to their wide range of biological properties are industrially important chemicals. Chemical synthesis of their optical isomers is expensive, time consuming and not friendly to the environment, so biotransformations are under consideration. Among others, these compounds act as enzymes inhibitors. This makes the bioconversions of phosphonates, especially scaling experiments, hard to perform. Biocatalysis is one of the methods that can be applied in synthesis of optically pure compounds...
February 2, 2018: Bioorganic Chemistry
Christoffel P S Badenhorst, Uwe T Bornscheuer
Applied biocatalysis is driven by environmental and economic incentives for using enzymes in the synthesis of various pharmaceutical and industrially important chemicals. Protein engineering is used to tailor the properties of enzymes to catalyze desired chemical transformations, and some engineered enzymes now outperform the best chemocatalytic alternatives by orders of magnitude. Unfortunately, custom engineering of a robust biocatalyst is still a time-consuming process, but an understanding of how enzyme function depends on amino acid sequence will speed up the process...
February 6, 2018: Trends in Biochemical Sciences
Shaghayegh Dezvarei, Joel H Z Lee, Stephen G Bell
The stereoselective oxidation of hydrocarbons is an area of research where enzyme biocatalysis can make a substantial impact. The cyclic ketone isophorone was stereoselectively hydroxylated (≥95%) by wild-type CYP102A1 to form (R)-4-hydroxyisophorone, an important chiral synthon and flavour and fragrance compound. CYP102A1 variants were also selective for 4-hydroxyisophorone formation and the product formation rate increased over the wild-type enzyme by up to 285-fold, with the best mutants being R47L/Y51F/I401P and A74G/F87V/L188Q...
April 2018: Enzyme and Microbial Technology
Danai S Gkotsi, Jag Dhaliwal, Matthew Mw McLachlan, Keith R Mulholand, Rebecca Jm Goss
No abstract text is available yet for this article.
February 1, 2018: Current Opinion in Chemical Biology
Yajie Wang, Hengqian Ren, Huimin Zhao
Biocatalysts have been increasingly used in the synthesis of fine chemicals and medicinal compounds due to significant advances in enzyme discovery and engineering. To mimic the synergistic effects of cascade reactions catalyzed by multiple enzymes in nature, researchers have been developing artificial tandem enzymatic reactions in vivo by harnessing synthetic biology and metabolic engineering tools. There is also growing interest in the development of one-pot tandem enzymatic or chemo-enzymatic processes in vitro due to their neat and concise catalytic systems and product purification procedures...
February 7, 2018: Critical Reviews in Biochemistry and Molecular Biology
Anna Bratek-Skicki, Pierre Eloy, Maria Morga, Christine C Dupont-Gillain
Proteins at interfaces are a key for many applications in the biomedical field, in biotechnologies, in biocatalysis, in food industry etc. The development of surface layers that allow to control and manipulate proteins is thus highly desired. In previous works, we have shown that mixed polymer brushes combining the protein-repellent properties of poly(ethylene oxide) (PEO) and the stimuli-responsive adsorption behavior of poly(acrylic acid) (PAA) could be synthesized and used to achieve switchable protein adsorption...
February 6, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Wei Geng, Li Wang, Nan Jiang, Jian Cao, Yu-Xuan Xiao, Hao Wei, Ali K Yetisen, Xiao-Yu Yang, Bao-Lian Su
Inspired by the characteristics of cells in live organisms, new types of hybrids have been designed comprising live cells and abiotic materials having a variety of structures and functionalities. The major goal of these studies is to uncover hybridization approaches that promote cell stabilization and enable the introduction of new functions into living cells. Single-cells in nanoshells have great potential in a large number of applications including bioelectronics, cell protection, cell therapy, and biocatalysis...
February 2, 2018: Nanoscale
Ana Julia Velez Rueda, Alexander Miguel Monzon, Sebastián M Ardanaz, Luis E Iglesias, Gustavo Parisi
BACKGROUND: Biocatalysis in organic solvents is nowadays a common practice with a large potential in Biotechnology. Several studies report that proteins which are co-crystallized or soaked in organic solvents preserve their fold integrity showing almost identical arrangements when compared to their aqueous forms. However, it is well established that the catalytic activity of proteins in organic solvents is much lower than in water. In order to explain this diminished activity and to further characterize the behaviour of proteins in non-aqueous environments, we performed a large-scale analysis (1737 proteins) of the conformational diversity of proteins crystallized in aqueous and co-crystallized or soaked in non-aqueous media...
January 30, 2018: BMC Bioinformatics
Ge Qu, Jing Zhao, Ping Zheng, Jibin Sun, Zhoutong Sun
Screening is the bottleneck of directed evolution. In order to address this problem, a series of novel semi-rational designed strategies have been developed based on combinatorial active-site saturation test and iterative saturation mutagenesis, including single code saturation mutagenesis, double code saturation mutagenesis and triple code saturation mutagenesis. By creation of "small and smart" high qualified mutant libraries and combinatorial mutagenesis of specific sites, these new strategies have been successfully applied in multiparameter optimization, e...
January 25, 2018: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Tek Chand Bhalla, Vijay Kumar, Virender Kumar, Neerja Thakur, Savitri
Nitrile metabolizing enzymes, i.e., aldoxime dehydratase, hydroxynitrile lyase, nitrilase, nitrile hydratase, and amidase, are the key catalysts in carbon nitrogen triple bond anabolism and catabolism. Over the past several years, these enzymes have drawn considerable attention as prominent biocatalysts in academia and industries because of their wide applications. Research on various aspects of these biocatalysts, i.e., sources, screening, function, purification, molecular cloning, structure, and mechanisms, has been conducted, and bioprocesses at various scales have been designed for the synthesis of myriads of useful compounds...
January 30, 2018: Applied Biochemistry and Biotechnology
Hannes Ludewig, Clarissa M Czekster, Emilia Oueis, Elizabeth S Munday, Mohammed Arshad, Silvia A Synowsky, Andrew F Bent, James H Naismith
Cyclic ribosomally derived peptides possess diverse bioactivities and are currently of major interest in drug development. However, it can be chemically challenging to synthesize these molecules, hindering the diversification and testing of cyclic peptide leads. Enzymes used in vitro offer a solution to this, however peptide macrocyclization remains the bottleneck. PCY1, involved in the biosynthesis of plant orbitides, belongs to the class of prolyl oligopeptidases and natively displays substrate promiscuity...
January 29, 2018: ACS Chemical Biology
Anne-Frances Miller, Jonathan T Park, Kyle L Ferguson, Warintra Pitsawong, Andreas S Bommarius
Nitroreductases (NRs) hold promise for converting nitroaromatics to aromatic amines. Nitroaromatic reduction rate increases with Hammett substituent constant for NRs from two different subgroups, confirming substrate identity as a key determinant of reactivity. Amine yields were low, but compounds yielding amines tend to have a large π system and electron withdrawing substituents. Therefore, we also assessed the prospects of varying the enzyme. Several different subgroups of NRs include members able to produce aromatic amines...
January 24, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Zhi Zou, Diana M Mate, Kristin Rübsam, Felix Jakob, Ulrich Schwaneberg
Sortase-catalyzed ligations have emerged as powerful tools for the site-specific ligation of peptides and proteins in material science and biocatalysis. In this work, a directed sortase evolution strategy (SortEvolve) has been developed as a general high-throughput screening (HTS) platform to improve activity of sortase A (Application 1) and to perform directed laccase evolution through a semi-purification process in 96-well microtiter plate (MTP) (Application 2). A semi-purification process in polypropylene MTP (PP-MTP) is achieved through the anchor peptide LCI which acts as adhesion promoter...
January 24, 2018: ACS Combinatorial Science
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