Теоретические основы интенсификации работы грануляционных устройств с усовершенствованной гидродинамикой

Одним із способів зменшення габаритів грануляційного обладнання є вдосконалення гідродинамічних умов перебування в ньому дисперсної фази. Цього можна досягти, зокрема, за рахунок застосування вихрових і високотурбулізованних потоків. Представлена робота присвячена обґрунтуванню можливості створення алгоритму управління рухом дисперсної фази в робочому просторі грануляційного пристрою, на підставі якого буде визначена його оптимальна конструкція з мінімальними габаритами.Одним из способов уменьшения габаритов грануляционного оборудования является усовершенствование гидродинамических условий пребывания в нём дисперсной фазы. Этого можно достичь, в частности, за счет применения вихревых и высокотурбулизованных потоков. Представленная работа посвящена обоснованию возможности создания алгоритма управления движением дисперсной фазы в рабочем пространстве грануляционного устройства, на основании которого будет определена его оптимальная конструкция с минимальными габаритами

On the Origins of Enzymes: Phosphate-Binding Polypeptides Mediate Phosphoryl Transfer to Synthesize Adenosine Triphosphate

Reactions involving the transfer of a phosphoryl (−PO32–) group are fundamental to cellular metabolism. These reactions are catalyzed by enzymes, often large and complex, belonging to the phosphate-binding loop (P-loop) nucleoside triphosphatase (NTPase) superfamily. Due to their critical importance in life, it is reasonable to assume that phosphoryl-transfer reactions were also crucial in the pre-LUCA (last universal common ancestor) world and mediated by precursors that were simpler, in terms of their sequence and structure, relative to their modern-day enzyme counterparts. Here, we demonstrate that short phosphate-binding polypeptides (∼50 residues) comprising a single, ancestrally inferred, P-loop or Walker A motif mediate the reversible transfer of a phosphoryl group between two adenosine diphosphate molecules to synthesize adenosine triphosphate and adenosine monophosphate. This activity, although rudimentary, bears resemblance to that of adenylate kinase (a P-loop NTPase enzyme). The polypeptides, dubbed as “P-loop prototypes”, thus relate to contemporary P-loop NTPases in terms of their sequence and function, and yet, given their simplicity, serve as plausible representatives of the early “founder enzymes” involved in proto-metabolic pathways

Role of Chemistry versus Substrate Binding in Recruiting Promiscuous Enzyme Functions

Two different scenarios for the recruitment of evolutionary starting points and their subsequent divergence to give new enzymes have been described. The coincidental, promiscuous starting activity may regard the same reaction chemistry on a new substrate (substrate ambiguity). Alternatively, substrate binding guides the recruitment of an enzyme whose reaction chemistry differs from that of the newly evolving one (catalytic promiscuity). While substrate ambiguity seems to underlie the divergence of most enzyme families, the relative levels of occurrence of these scenarios remain unknown. Screening the Escherichia coli proteome with a comparative series of xenobiotic substrates, we found that substrate ambiguity was, as anticipated, more frequent than reaction promiscuity. However, for at least one unnatural reaction (phosphonoesterase), a promiscuous enzyme was identified only when the substrate was decorated with the naturally abundant phosphate group. These findings support the prevailing hypothesis of chemistry-driven divergence but also suggest that recognition of familiar substrate motifs plays a role. In the absence of enzymes catalyzing the same chemistry, having a familiar, naturally occurring substrate motif (chemophore) such as phosphate may increase the likelihood of catalytic promiscuity. Chemophore anchoring may also find practical applications in identifying catalysts for unnatural reactions

Dual Labeling of Metabolites for Metabolome Analysis (DLEMMA): A New Approach for the Identification and Relative Quantification of Metabolites by Means of Dual Isotope Labeling and Liquid Chromatography−Mass Spectrometry

Advanced metabolomics technologies are anticipated to permit the identification and quantification of metabolites at the whole-metabolome scale. Yet, most of the metabolites either remain unknown or cannot be identified unambiguously. Moreover, the present approaches suffer from inaccuracies in relative quantification because of sample preparation and matrix effects. Here we present Dual Labeling of Metabolites for Metabolome Analysis (DLEMMA) as a valuable tool, which with analogy to DNA array assays enables the identification and relative quantification of differential metabolites in a single sample. DLEMMA was demonstrated as an efficient method for reducing the number of possible chemical structures assigned that exhibit the same elemental composition. Its strength was exemplified by the discovery of 10 novel Tryptophan derivatives. Furthermore, employing DLEMMA by feeding two Phenylalanine-labeled precursors, we could detect differential metabolites between transgenic and control plants. The accuracy of relative quantification is also enhanced since DLEMMA provides identical matrixes for both samples, thus avoiding the effects of different complex biological matrixes on electrospray ionization. Hence, DLEMMA will complement and contribute to the advancement of metabolomics technologies and boost metabolic pathway discovery in diverse organisms

DataSheet_1_2-NBDG Uptake in Gossypium hirsutum in vitro ovules: exploring tissue-specific accumulation and its impact on hexokinase-mediated glycolysis regulation.pdf

Fluorescent glucose derivatives are valuable tools as glucose analogs in plant research to explore metabolic pathways, study enzyme activity, and investigate cellular processes related to glucose metabolism and sugar transport. They allow visualization and tracking of glucose uptake, its utilization, and distribution within plant cells and tissues. This study investigates the phenotypic and metabolic impact of the exogenously fed glucose derivative, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose) (2-NBDG) on the fibers of Gossypium hirsutum (Upland cotton) ovule in vitro cultures. The presence of 2-NBDG in the culture medium did not lead to macroscopic morphological alterations in ovule and fiber development or to the acquisition of fluorescence or yellow coloration. Confocal laser scanning microscope imaging and chromatographic analysis of cotton ovules’ outer rim cross-sections showed that the 2-NBDG is transported from the extracellular space and accumulated inside some outer integument cells, epidermal cells, and fertilized epidermal cells (fibers), but is not incorporated into the cell walls. Untargeted metabolic profiling of the fibers revealed significant changes in the relative levels of metabolites involved in glycolysis and upregulation of alternative energy-related pathways. To provide biochemical and structural evidence for the observed downregulation of glycolysis pathways in the fibers containing 2-NBDG, kinetics analysis and docking simulations were performed on hexokinase from G. hirsutum (GhHxk). Notably, the catalytic activity of heterologously expressed recombinant active GhHxk exhibited a five-fold decrease in reaction rates compared to D-glucose. Furthermore, GhHxk exhibited a linear kinetic behavior in the presence of 2-NBDG instead of the Michaelis-Menten kinetics found for D-glucose. Docking simulations suggested that 2-NBDG interacts with a distinct binding site of GhHxk9, possibly inducing a conformational change. These results highlight the importance of considering fluorescent glucose derivatives as ready-to-use analogs for tracking glucose-related biological processes. However, a direct comparison between their mode of action and its extrapolation into biochemical considerations should go beyond microscopic inspection and include complementary analytical techniques.</p

Choice oviposition

Choice ovipositio

Egg and nymph survival Q

Egg and nymph survival

Survival on sinigrin

Survival on sinigri

Development Q

Development

Development B

Development