Identification of a Novel Self-Sufficient Styrene Monooxygenase from Rhodococcus opacus 1CP.

Sequence analysis of a 9-kb genomic fragment of the actinobacterium Rhodococcus opacus 1CP led to identification of an open reading frame encoding a novel fusion protein, StyA2B, with a putative function in styrene metabolism via styrene oxide and phenylacetic acid. Gene cluster analysis indicated that the highly related fusion proteins of Nocardia farcinica IFM10152 and Arthrobacter aurescens TC1 are involved in a similar physiological process. Whereas 413 amino acids of the N terminus of StyA2B are highly similar to those of the oxygenases of two-component styrene monooxygenases (SMOs) from pseudomonads, the residual 160 amino acids of the C terminus show significant homology to the flavin reductases of these systems. Cloning and functional expression of His10-StyA2B revealed for the first time that the fusion protein does in fact catalyze two separate reactions. Strictly NADH-dependent reduction of flavins and highly enantioselective oxygenation of styrene to (S)-styrene oxide were shown. Inhibition studies and photometric analysis of recombinant StyA2B indicated the absence of tightly bound heme and flavin cofactors in this self-sufficient monooxygenase. StyA2B oxygenates a spectrum of aromatic compounds similar to those of two-component SMOs. However, the specific activities of the flavin-reducing and styrene-oxidizing functions of StyA2B are one to two orders of magnitude lower than those of StyA/StyB from Pseudomonas sp. strain VLB120

The Role of Specific ATP-Binding Cassette Transporters in the Acquired Resistance to Pyrrolobenzodiazepine Dimer-Containing Antibody-Drug Conjugates

Antibody–drug conjugates (ADC) containing pyrrolobenzodiazepine (PBD) dimers are being evaluated clinically in both hematologic and solid tumors. These include ADCT-301 (camidanlumab tesirine) and ADCT-402 (loncastuximab tesirine) in pivotal phase II trials that contain the payload tesirine, which releases the PBD dimer warhead SG3199. An important consideration in future clinical development is acquired resistance. The aim was to generate and characterize PBD acquired resistant cell lines in both hematologic and solid tumor settings. Human Karpas-299 (ALCL) and NCI-N87 (gastric cancer) cells were incubated with increasing IC50 doses of ADC (targeting CD25 and HER2, respectively) or SG3199 in a pulsed manner until stable acquired resistance was established. The level of resistance achieved was approximately 3,000-fold for ADCT-301 and 3-fold for SG3199 in Karpas-299, and 8-fold for ADCT-502 and 4-fold for SG3199 in NCI-N87. Cross-resistance between ADC and SG3199, and with an alternative PBD-containing ADC or PBD dimer was observed. The acquired resistant lines produced fewer DNA interstrand cross-links, indicating an upstream mechanism of resistance. Loss of antibody binding or internalization was not observed. A human drug transporter PCR Array revealed several genes upregulated in all the resistant cell lines, including ABCG2 and ABCC2, but not ABCB1(MDR1). These findings were confirmed by RT-PCR and Western blot, and inhibitors and siRNA knockdown of ABCG2 and ABCC2 recovered drug sensitivity. These data show that acquired resistance to PBD-ADCs and SG3199 can involve specific ATP-binding cassette drug transporters. This has clinical implications as potential biomarkers of resistance and for the rational design of drug combinations

Оцінювання закону розподілу величини збитків унаслідок реалізації загрози “Відсутність або недостатність технічного обслуговування”

The problem of estimation of size distribution law of damages in the absence or insufficient sample size of the universe and the initial data suggested approach to finding the most expected value of losses due to information security threats

Crystal Structure of 3-Hydroxybenzoate 6-Hydroxylase Uncovers Lipid-assisted Flavoprotein Strategy for Regioselective Aromatic Hydroxylation.

3-Hydroxybenzoate 6-hydroxylase (3HB6H) from Rhodococcus jostii RHA1 is a dimeric flavoprotein that catalyzes the NADH- and oxygen-dependent para-hydroxylation of 3-hydroxybenzoate to 2,5-dihydroxybenzoate. In this study, we report the crystal structure of 3HB6H as expressed in Escherichia coli. The overall fold of 3HB6H is similar to that of p-hydroxybenzoate hydroxylase and other flavoprotein aromatic hydroxylases. Unexpectedly, a lipid ligand is bound to each 3HB6H monomer. Mass spectral analysis identified the ligand as a mixture of phosphatidylglycerol and phosphatidylethanolamine. The fatty acid chains occupy hydrophobic channels that deeply penetrate into the interior of the substrate-binding domain of each subunit, whereas the hydrophilic part is exposed on the protein surface, connecting the dimerization domains via a few interactions. Most remarkably, the terminal part of a phospholipid acyl chain is directly involved in the substrate-binding site. Co-crystallized chloride ion and the crystal structure of the H213S variant with bound 3-hydroxybenzoate provide hints about oxygen activation and substrate hydroxylation. Essential roles are played by His-213 in catalysis and Tyr-105 in substrate binding. This phospholipid-assisted strategy to control regioselective aromatic hydroxylation is of relevance for optimization of flavin-dependent biocatalysts

Kindermishandeling tijdens de tweede lockdown

Education and Child Studie

Calculating the random guess scores of multiple-response and matching test items

For achievement tests, the guess score is often used as a baseline for the lowest possible grade for score to grade transformations and setting the cut scores. For test item types such as multiple-response, matching and drag-and-drop, determin-ing the guess score requires more elaborate calculations than the more straight-forward calculation of the guess score for True-False and multiple-choice test item formats. For various variants of multiple-response and matching types with respect to dichotomous and polytomous scoring, methods for determining the guess score are presented and illustrated with practical applications. The implica-tions for theory and practice are discussed

Sorghum grain as human food in Africa: relevance of content of starch and amylase activities

Sorghum is a staple food grain in many semi-arid and tropic areas of the world, notably in Sub-Saharan Africa because of its good adaptation to hard environments and its good yield of production. Among important biochemical components for sorghum processing are levels of starch (amylose and amylopectin) and starch depolymerizing enzymes. Current research focus on identifying varieties meeting specific agricultural and food requirements from the great biodiversity of sorghums to insure food security. Results show that some sorghums are rich sources of micronutrients (minerals and vitamins) and macronutrients (carbohydrates, proteins and fat). Sorghum has a resistant starch, which makes it interesting for obese and diabetic people. In addition, sorghum may be an alternative food for people who are allergic to gluten. Malts of some sorghum varieties display a-amylase and ß-amylase activities comparable to those of barley, making them useful for various agro-industrial foods. The feature of sorghum as a food in developing as well as in developed countries is discussed. A particular emphasis is made on the impact of starch and starch degrading enzymes in the use of sorghum for some African foods, e.g. “tô”, thin porridges for infants, granulated foods “couscous”, local beer “dolo”, as well agro-industrial foods such as lager beer and bread.Keywords: sorghum, a-amylase, b-amylase, starch, infant porridge, beer, couscous, dolo, tô, brea

Data-driven System Identification of Thermal Systems using Machine Learning

The paper addresses the identification of spatial-temporal mirror surface deformations as a result of laser-based heat load within the lithography process of integrated circuit production. The thermal diffusion and surface deformation are modeled by separation of the spatial-temporal effects using data-driven orthogonal decomposition. A novel tree adjoining grammar (TAG) and sparsity enhanced symbolic-regression-based learning methods are deployed to discover temporal dynamics that connect the spatial variation. The resulting data-driven procedure is applied to automatically synthetise a compact model representation of synthetic thermal effects induced mirror surface deformations