Functional Characterization and Synthetic Application of Is2-SDR, a Novel Thermostable and Promiscuous Ketoreductase from a Hot Spring Metagenome.

In a metagenome mining-based search of novel thermostable hydroxysteroid dehydrogenases (HSDHs), enzymes that are able to selectively oxidize/reduce steroidal compounds, a novel short-chain dehydrogenase/reductase (SDR), named Is2-SDR, was recently discovered. This enzyme, found in an Icelandic hot spring metagenome, shared a high sequence similarity with HSDHs, but, unexpectedly, showed no activity in the oxidation of the tested steroid substrates, e.g., cholic acid. Despite that, Is2-SDR proved to be a very active and versatile ketoreductase, being able to regio- and stereoselectively reduce a diversified panel of carbonylic substrates, including bulky ketones, α- and ß-ketoesters, and α-diketones of pharmaceutical relevance. Further investigations showed that Is2-SDR was indeed active in the regio- and stereoselective reduction of oxidized steroid derivatives, and this outcome was rationalized by docking analysis in the active site model. Moreover, Is2-SDR showed remarkable thermostability, with an apparent melting temperature (TM) around 75 °C, as determined by circular dichroism analysis, and no significant decrease in catalytic activity, even after 5 h at 80 °C. A broad tolerance to both water-miscible and water-immiscible organic solvents was demonstrated as well, thus, confirming the potential of this new biocatalyst for its synthetic application.

Stereoselective Biocatalyzed Reductions of Ginger Active Components Recovered from Industrial Wastes.

Ginger is among the most widespread and widely consumed traditional medicinal plants around the world. Its beneficial effects, which comprise e. g. anticancer and anti-inflammatory activities as well as gastrointestinal regulatory effects, are generally attributed to a family of non-volatile compounds characterized by an arylalkyl long-chained alcohol, diol, or ketone moiety. In this work, ginger active components have been successfully recovered from industrial waste biomass of fermented ginger. Moreover, their recovery has been combined with the first systematic study of the stereoselective reduction of gingerol-like compounds by isolated alcohol dehydrogenases (ADHs), obtaining the enantioenriched sec-alcohol derivatives via a sustainable biocatalytic path in up to >99 % conversions and >99 % enantiomeric/diastereomeric excesses.

Volleyball-Specific Skills and Cognitive Functions Can Discriminate Players of Different Competitive Levels.

ABSTRACT: Formenti, D, Trecroci, A, Duca, M, Vanoni, M, Ciovati, M, Rossi, A, and Alberti, G. Volleyball-specific skills and cognitive functions can discriminate players of different competitive levels. J Strength Cond Res 36(3): 813-819, 2022-The aim of this study was to investigate whether volleyball-specific skills, physical performance, and general cognitive functions differ between players of different competitive levels. Twenty-six female volleyball players competing at 2 different levels (n = 13, regional; n = 13, provincial) were tested on volleyball-specific skills (accuracy and technique of setting, passing, spiking, and serving), change of direction speed (COD) by the modified T-test, countermovement jump (CMJ) and general cognitive functions (executive control by Flanker task and perceptual speed by visual search task). Four machine learning models were tested to detect the best one to predict players' level. Regional players presented higher passing, spiking, serving accuracy (p < 0.05) and setting, passing, spiking, and serving technique (p < 0.05) than provincial players. Regional players had also better performance in COD and CMJ than provincial players (p < 0.05). Regional players presented lower response time than provincial players in both congruent and incongruent conditions of the Flanker task, and in both 10 items and 15 items conditions of the visual search task (p < 0.05). Decision tree classifier was the machine learning model with the highest performance to discriminate regional and provincial players (93% precision and 73% recall) by considering passing technique, congruent and incongruent condition of the Flanker task, 15 items and 10 items condition of the visual search task, and spiking technique. These findings demonstrated the importance of assessing volleyball-specific skills and cognitive functions as playing a role to discriminate players of different competitive levels.

Discovery and Characterization of a Novel Thermostable ß-Amino Acid Transaminase from a Meiothermus Strain Isolated in an Icelandic Hot Spring.

A Meiothermus strain capable of using ß-phenylalanine for growth is isolated by culture enrichment of samples collected in hot environments and the genome is sequenced showing the presence of 22 putative transaminase (TA) sequences. On the basis of phylogenetic and sequence analysis, a TA termed Ms-TA2 is selected for further studies. The enzyme is successfully produced in Escherichia coli Rosetta(DE3) cells, with 70 mg of pure protein obtained from 1 L culture after purification by affinity chromatography. Ms-TA2 shows high activity toward (S)-ß-phenylalanine and other (S)-ß-amino acids, as well as a preference for α-ketoglutarate and aromatic aldehydes as amino acceptors. Moreover, Ms-TA2 is shown to be a thermostable enzyme by maintaining about 60% of the starting activity after 3 h incubation at 50 °C and showing a melting temperature of about 73 °C. Finally, a homology-based structural model of Ms-TA2 is built and key active site interactions for substrate and cofactor binding are analyzed.