Our previous studies indicated that endophyte M7SB41 (Seimatosporium sp.) can significantly enhance host plants powdery mildew (PM) resistance. To recover the mechanisms, differentially expressed ...genes (DEGs) were compared between E+ (endophte-inoculated) and E− (endophyte-free) plants by transcriptomics. A total of 4094, 1200 and 2319 DEGs between E+ and E− were identified at 0, 24, and 72 h after plants had been infected with PM pathogen Golovinomyces cichoracearum, respectively. Gene expression pattern analysis displayed a considerable difference and temporality in response to PM stress between the two groups. Transcriptional profiling analysis revealed that M7SB41 induced plant resistance to PM through Casup.2+ signaling, salicylic acid (SA) signaling, and the phenylpropanoid biosynthesis pathway. In particular, we investigated the role and the timing of the SA and jasmonic acid (JA)-regulated defensive pathways. Both transcriptomes and pot experiments showed that SA-signaling may play a prominent role in PM resistance conferred by M7SB41. Additionally, the colonization of M7SB41 could effectively increase the activities and the expression of defense-related enzymes under PM pathogen stress. Meanwhile, our study revealed reliable candidate genes from TGA (TGACG motif-binding factor), WRKY, and pathogenesis-related genes related to M7SB41-mediate resistance. These findings offer a novel insight into the mechanisms of endophytes in activating plant defense responses.
Biocatalysts (enzymes and whole cells) catalyze reactions with the advantage of superior chemo-, regio-, and stereo-specificity in mild conditions, thereby avoiding the production of larger amounts ...of waste. The currently great practical importance of immobilized biocatalysts is expressed by the high number of scientific publications together with an ever increasing number of different applications in this area of enzyme technology. This mainly relies on new research results with respect to immobilization techniques and the development of advanced carrier materials designed for this purpose.
The employment of immobilized biocatalysts is one of the most effective and powerful tools used in the modern chemical industry as a prerequisite for an economical and environmentally friendly production process. The book presented here reflects the currently great practical importance of immobilized biocatalysts by means of a variety of actual examples. They comprise the immobilization of enzymes from different enzyme classes and a variety of whole cells with particular importance for the production of compounds for application in the chemical, pharmaceutical and food industry (in part from renewable resources), biohydrogen production, the fabrication of biosensors, and the treatment of waste water. Several articles introduce new research results with respect to immobilization techniques and the development of carrier materials designed for this purpose.
In addition, review articles provide among others an overview of the industrial application of immobilized biocatalysts in various areas including the energy sector, or discuss the many advantages of metal–organic frameworks (MOFs) as platforms for enzyme immobilization. They deal with the pros and cons of many inorganic, organic, hybrid and composite materials, including nano-supports, used for the immobilization of biocatalysts, and with the development of engineered strains applied to the conversion of lignocellulosic biomass to platform chemicals by consolidated bioprocessing.
In summary, the articles meet the state of the art of both scientific and technical standards and the book is indispensable for all those involved in the various aspects of this topic.
•An overview of applications of enzyme based therapies (EBTs).•Provides historical, clinical, and regulatory context for EBT market growth and decline.•A review of both approved and investigational ...therapies.•Discusses challenges facing EBTs that could be addressed with enzyme engineering.•Specific, relevant examples of targets for enzyme engineering for improved EBTs.
Enzyme-based therapeutics (EBTs) have the potential to tap into an almost unmeasurable amount of enzyme biodiversity and treat myriad conditions. Although EBTs were some of the first biologics used clinically, the rate of development of newer EBTs has lagged behind that of other biologics. Here, we review the history of EBTs, and discuss the state of each class of EBT, their potential clinical advantages, and the unique challenges to their development. Additionally, we discuss key remaining technical barriers that, if addressed, could increase the diversity and rate of the development of EBTs.
One new ent-pimarane-type diterpenoid (1), along with 10 known compounds, were isolated from the leaves of Croton oligandrus. Compounds 2 and 3 are reported for the first time from this species. The ...extract and some of the isolates were tested in vitro for their inhibitory properties toward urease and butyrylcholinesterase enzymes, as well as DPPH radical scavenging potency, respectively. Compound 6 (IC.sub.50 = 29.2 muM) was the most active on urease, while compound 4 (IC.sub.50 = 18.2 muM) showed the best inhibitory activity against butyrylcholinesterase. The new isolate, compound 1, with an IC.sub.50 value of 39.4 muM revealed potent antioxidant activity.
Lipases are the most widely used enzymes in biocatalysis, and the most utilized method for enzyme immobilization is using hydrophobic supports at low ionic strength. This method allows the one step ...immobilization, purification, stabilization, and hyperactivation of lipases, and that is the main cause of their popularity. This review focuses on these lipase immobilization supports. First, the advantages of these supports for lipase immobilization will be presented and the likeliest immobilization mechanism (interfacial activation on the support surface) will be revised. Then, its main shortcoming will be discussed: enzyme desorption under certain conditions (such as high temperature, presence of cosolvents or detergent molecules). Methods to overcome this problem include physical or chemical crosslinking of the immobilized enzyme molecules or using heterofunctional supports. Thus, supports containing hydrophobic acyl chain plus epoxy, glutaraldehyde, ionic, vinylsulfone or glyoxyl groups have been designed. This prevents enzyme desorption and improved enzyme stability, but it may have some limitations, that will be discussed and some additional solutions will be proposed (e.g., chemical amination of the enzyme to have a full covalent enzyme-support reaction). These immobilized lipases may be subject to unfolding and refolding strategies to reactivate inactivated enzymes. Finally, these biocatalysts have been used in new strategies for enzyme coimmobilization, where the most stable enzyme could be reutilized after desorption of the least stable one after its inactivation.
•Lipases immobilization on hydrophobic supports via interfacial activation is described in this review•This protocol permits the one step immobilization, purification, stabilization and hyperactivation of lipases•Lipases may be released from the support under certain conditions•Intermolecular crosslinking may prevent enzyme release•Heterofunctional supports prevent enzyme release but they have some limitations•There are many ways of taking full advantage of the new heterofunctional supports
DOI: 10.1002/pmic.201500433 Metabolizing enzymes and transporters are key molecules that function cooperatively to regulate the absorption, metabolism and excretion of medicinal drugs. Absolute ...protein levels of 30 metabolizing enzymes and 107 transporters were simultaneously quantified in microsomes of human liver, kidney and intestine by means of SWATH-MS with stable isotope-labeled peptides, and the results were compared with those obtained by MRM/SRM and high resolution-MRM/PRM. For more details, see the article by Kenji Nakamura et al. on pages 2106-2117.
E1 enzymes function as gatekeepers of ubiquitin (Ub) signaling by catalyzing activation and transfer of Ub to tens of cognate E2 conjugating enzymes in a process called E1-E2 transthioesterification. ...The molecular mechanisms of transthioesterification and the overall architecture of the E1-E2-Ub complex during catalysis are unknown. Here, we determine the structure of a covalently trapped E1-E2-ubiquitin thioester mimetic. Two distinct architectures of the complex are observed, one in which the Ub thioester (Ub(t)) contacts E1 in an open conformation and another in which Ub(t) instead contacts E2 in a drastically different, closed conformation. Altogether our structural and biochemical data suggest that these two conformational states represent snapshots of the E1-E2-Ub complex pre- and post-thioester transfer, and are consistent with a model in which catalysis is enhanced by a Ub(t)-mediated affinity switch that drives the reaction forward by promoting productive complex formation or product release depending on the conformational state.
Immobilization of enzymes enhances their properties for efficient utilization in industrial processes. Magnetic nanoparticles, due to their high surface area, large surface-to-volume ratio and easy ...separation under external magnetic fields, are highly valued. Significant progress has been made to develop new catalytic systems that are immobilized onto magnetic nanocarriers. This review provides an overview of recent developments in enzyme immobilization and stabilization protocols using this technology. The current applications of immobilized enzymes based on magnetic nanoparticles are summarized and future growth prospects are discussed. Recommendations are also given for areas of future research.
E1 enzymes activate ubiquitin (Ub) and ubiquitin-like modifiers (Ubls) in the first step of Ub/Ubl conjugation cascades and represent potential targets for therapeutic intervention in cancer and ...other life-threatening diseases. Here, we report the crystal structure of the E1 enzyme for the Ubl SUMO in complex with a recently discovered and highly specific covalent allosteric inhibitor (COH000). The structure reveals that COH000 targets a cryptic pocket distinct from the active site that is completely buried in all previous SUMO E1 structures and that COH000 binding to SUMO E1 is accompanied by a network of structural changes that altogether lock the enzyme in a previously unobserved inactive conformation. These structural changes include disassembly of the active site and a 180° rotation of the catalytic cysteine-containing SCCH domain, relative to conformational snapshots of SUMO E1 poised to catalyze adenylation. Altogether, our study provides a molecular basis for the inhibitory mechanism of COH000 and its SUMO E1 specificity, and also establishes a framework for potential development of molecules targeting E1 enzymes for other Ubls at a cryptic allosteric site.
Enzymes are biocatalysts that speed up the reactions taking place inside the cell. They are widely used in industries, scientific research and clinical diagnostics. Enzymes are specific for their ...substrates. They increase the rate of reaction by lowering the activation energy required to convert the substrates into the products. The catalysis by an enzyme is influenced by the nature of medium, substrate, enzyme concentration, temperature, pH, and the presence of activators and inhibitors. Nanoparticles are solid dispersion particulates of size range 10–1000 nm. They cause enhancement of particle mobility, diffusion, thermal stability, storage capacity, greater surface area and also modulate catalytic activity of the attached enzymes. Enzymes can be immobilized on nanoparticles by simple adsorption or via chemical linkages. Immobilization is a commercially applicable and a convenient method because it usually results in enhanced thermal and pH stabilities of the enzyme, lower cost of production, reusability with easy handling and separation. Primary objective of writing this review is to give an overview of the various aspects of enzymology, enzyme catalysis, enzyme immobilization and modulation of enzyme activity with special emphasis on modulation through different types of nanoparticles including their synthesis, characterization and applications.
•Enzymes are biocatalysts and have wide applications.•Enzyme catalysis is influenced by a number of factors.•A variety of nanostructures are being synthesized.•Enzymes can be immobilized on nanoparticles by adsorption or via chemical linkages.•Nanoparticles modulate activity and usually increase the stability of bound enzymes.
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