Stand-alone lipoylated H-protein of the glycine cleavage system enables glycine cleavage and the synthesis of glycine from one-carbon compounds in vitro

H-protein, one of the four component proteins (H, T, P and L) of glycine cleavage system (GCS), is generally considered a shuttle protein interacting with the other three GCS-proteins via a lipoyl swinging arm. We report that without P-, T- and L-proteins, lipoylated H-protein (Hlip) enables GCS reactions in both glycine cleavage and synthesis directions in vitro. This apparent catalytic activity is closely related to the cavity on the H-protein surface where the lipoyl arm is attached. Heating or mutation of selected residues in the cavity destroys or reduces the stand-alone activity of Hlip, which can be restored by adding the other three GCS-proteins. Systematic study of the Hlip-catalyzed overall GCS reactions and the individual reaction steps provides a first step towards understanding the stand-alone function of Hlip. The results in this work provide some inspiration for further understanding the mechanism of the GCS and give some interesting implications on the evolution of the GCS.

A Mobile Analytical Device for On-Site Quantitation of Anthocyanins in Fruit Beverages

Anthocyanins are antioxidant and anti-inflammatory ingredients in various fruit beverages, for which their conservation and quantitation are important for the food industry. In this paper, we report a simple, portable device for accurate on-site determination of total monomeric anthocyanins in fruit beverages employing a Wi-Fi scanner coupled with a flexible microchip and a free mobile app. The detection principle is based on the pH-induced colorimetric reactions of anthocyanins performed in a specially designed microchip and validated with standard spectrophotometric measurements. The microchip with multiple testing vials was prepared with the benchtop molding method with a common PDMS elastomer and a transparency film; the photo of the scanned microchip is wirelessly sent to a smartphone and the RGB values of individual reaction vials in the microchip are analyzed with a free mobile app to determine the corresponding concentrations. It was demonstrated that the quantitation performance of this POCT device is comparable with conventional spectrophotometry in the determination of total anthocyanins in both standard solutions and fruit beverages.

REAÇÕES EM CASCATA ENZIMÁTICA, QUIMIOENZIMÁTICA E FOTOENZIMÁTICA: PERSPECTIVAS PARA UMA SÍNTESE ORGÂNICA MAIS SUSTENTÁVEL

ENZYMATIC, CHEMOENZYMATIC AND PHOTOENZYMATIC CASCADE REACTIONS: PERSPECTIVES FOR A MORE SUSTAINABLE ORGANIC SYNTHESIS. Chemicals are rarely the result of a single transformation but rather the consequence of several individual reaction steps. Classically, these individual steps are carried out in sequence, including isolation and purification of the intermediate products. However, the reasons for choosing to carry out cascade reactions can be multiple, such as (i) the chance to prepare unstable and/or toxic intermediates, which are consumed directly in a subsequent step, (ii) the option to shift the equilibrium of a reaction by removing the co (product), or (iii) simply bypass the tedious work of isolating and purifying intermediates, saving reagents, solvents, time and money, and still generating less waste. Therefore, it is not surprising that so-called cascade reactions are gaining considerable interest in academic and industrial research. The purpose of this review is to show recent, promising research and new trends, the potential and current limitations of cascade reactions in organic synthesis that involves at least one enzymatic step in the cascade. This review will address cascades involving multi enzymatic, chemoenzymatic, and photoenzymatic cascades, where all steps are performed in one reaction vessel simultaneously or sequentially and the cascades in the regime of continuous flow.

Bifurcation analysis of a SEIR epidemic system with governmental action and individual reaction

In this paper, the dynamical behavior of a SEIR epidemic system that takes into account governmental action and individual reaction is investigated. The transmission rate takes into account the impact of governmental action modeled as a step function while the decreasing contacts among individuals responding to the severity of the pandemic is modeled as a decreasing exponential function. We show that the proposed model is capable of predicting Hopf bifurcation points for a wide range of physically realistic parameters for the COVID-19 disease. In this regard, the model predicts periodic behavior that emanates from one Hopf point. The model also predicts stable oscillations connecting two Hopf points. The effect of the different model parameters on the existence of such periodic behavior is numerically investigated. Useful diagrams are constructed that delineate the range of periodic behavior predicted by the model.

May I have your attention, please? Methodological and Analytical Flexibility in the Addiction Stroop

Theoretical models of addiction predict that an attentional bias towards drug/alcohol related cues plays a key role in development and maintenance of addictive behaviours. However, data from the empirical research testing these predictions is equivocal. This ambiguity may in part be a consequence of substantial variability in the methods used to operationalise attentional bias. The aim of this research was to examine the variability in key design and analysis decisions of the addiction Stroop. Using a pre-registered design, we systematically searched the literature and identified 46 studies describing an alcohol Stroop task and 25 studies describing a smoking Stroop task. We extracted information about the design of the Stroop task, including but not limited to; administration (paper-and-pencil vs. computerised), response (key press vs. voice), number of drug-related stimuli used, number of stimulus repetitions, design (block vs. mixed). For analysis decisions we extracted information on upper- and lower-bound reaction time cut-offs, removal of individual reaction times based on standard error cut-offs, removal of participants based on overall performance, type of outcome used, and removal of errors. Based on variability from previous research there are at least 1,451,520 different possible designs of the computerised alcohol Stroop and 77,760 designs of the computerised smoking Stroop. Many key design decisions were unreported. Similarly, variability in analyses decisions would allow for 9,000 different methods for analysing the alcohol Stroop and 5,376 for the smoking Stroop. This flexibility in the design and analysis of a widely used measure of attentional bias may contribute to equivocal findings, unreliable tasks and inability to replicate research. Future research should work towards a gold standard addiction Stroop with reliable psychometric properties. This will allow us to confidently test predictions and lead to progress within the field.

Ecologization of apple seedlings cultivation

The influence of microbial preparations (MP) on the growth and condition of apple ( Malus domestica Borkh.) seedlings and the nutrition elements regime of the soil in the fruit nursery in two cultivars: Golden Delicious and Rennet Simirenko on the stock EM-IX have been studied. It was established that the applied MPs had a positive effect on the growth, condition of the rootstocks, the survival rate of the graft eyes and the degree of their winter hardiness. The stimulating influence of MP on the growth and yield of grafted apple seedlings has been established. Nutritional conditions improved and the content of mobile forms of element nutrition increases in the rhizosphere of seedlings. The individual reaction of the cultivar to interaction with the introduced bacteria is shown.

Особенности формирования фитосанитарной ситуации в посадках цветных сортов картофеля и его продуктивность при различных системах защиты растений

Data were obtained on the peculiarities of the development of black scab on four varieties of colored potatoes (Violet, Purple Majesty, All Red and Rosamaria) when culvaed using chemical and biologized plant protection systems. It is shown, that the development of black scab and its infestation of stolons on varieties grown with the use of chemical plant protetion agents is lower than with the use of biological preparations, respectively, by 2.4-6.5 times and by 4%. The biometric indicators of plants when they were grown using the chemical protection system were slightly higher than those on biologized ones. The individual reaction of varieties to the studied protective techniques was revealed. Among the four studied cultivars, the cultivar All Red stood out, in which the phytosanitary condition of plantings, productivity indicators on both protection systems were similar.

Effectiveness of foliar treatment of intensive varieties of spring barleycorn under the conditions of Middle Volga region

Experimental studies were conducted in 2015–2017 on Agat and Povolzhsky 22 barleycorn varieties in order to identify the effectiveness of foliar treatments with modern drugs. The treatments increased the yield of varieties to 28%. Grain quality indicators did not change. An individual reaction of barleycorn varieties to yield and grain quality was revealed. During the use of the Biostim Grain drug, Souffler + Intermag complexes of Profi Grain and Mival-Agro + Lignogumat + Zelenit N, the net income reached 3561 rubles/ha, and the profitability was 221%.