Mitigation of reactive metabolite formation for a series of 3-amino-2-pyridone inhibitors of Bruton’s tyrosine kinase (BTK)

Reactive metabolites have been putatively linked to many adverse drug reactions including idiosyncratic toxicities for a number of drugs with black box warnings or withdrawn from the market. Therefore, it is desirable to minimize the risk of reactive metabolite formation for lead molecules in optimization, in particular for non-life threatening chronic disease, to maximize benefit to risk ratio. This article describes our effort in addressing reactive metabolite issues for a series of 3-amino-2-pyridone inhibitors of BTK, e.g. compound 1 has a value of 459 pmol/mg protein in the microsomal covalent binding assay. Parallel approaches were taken to successfully resolve the issues: establishment of a predictive screening assay with correlation association of covalent binding assay, identification of the origin of reactive metabolite formation using MS/MS analysis of HLM as well as isolation and characterization of GSH adducts. This ultimately led to the discovery of compound 7 (RN941) with significantly reduced covalent binding of 26 pmol/mg protein.     

Non-nucleoside inhibitors of HCV polymerase NS5B. Part 2: Synthesis and structure–activity relationships of benzothiazine-substituted quinolinediones

A new series of benzothiazine-substituted quinolinediones were evaluated as inhibitors of HCV polymerase NS5B. SAR studies on this series revealed a methyl sulfonamide group as a high affinity feature. Analogues with this group showed submicromolar potencies in the HCV cell based replicon assay. Pharmacokinetic and toxicology studies were also performed on a selected compound (34) to evaluate in vivo properties of this new class of inhibitors of HCV NS5B polymerase.     

Ligand Recognition of the Major Birch Pollen Allergen Bet v 1 is Isoform Dependent

Each spring millions of patients suffer from allergies when birch pollen is released into the air. In most cases, the major pollen allergen Bet v 1 is the elicitor of the allergy symptoms. Bet v 1 comes in a variety of isoforms that share virtually identical conformations, but their relative concentrations are plant-specific. Glycosylated flavonoids, such as quercetin-3-O-sophoroside, are the physiological ligands of Bet v 1, and here we found that three isoforms differing in their allergenic potential also show an individual, highly specific binding behaviour for the different ligands. This specificity is driven by the sugar moieties of the ligands rather than the flavonols. While the influence of the ligands on the allergenicity of the Bet v 1 isoforms may be limited, the isoform and ligand mixtures add up to a complex and thus individual fingerprint of the pollen. We suggest that this mixture is not only acting as an effective chemical sunscreen for pollen DNA, but may also play an important role in recognition processes during pollination.     

Structural and mutational analysis of the cell division protein FtsQ

Bacterial cytokinesis requires the divisome, a complex of proteins that co-ordinates the invagination of the cytoplasmic membrane, inward growth of the peptidoglycan layer and the outer membrane. Assembly of the cell division proteins is tightly regulated and the order of appearance at the future division site is well organized. FtsQ is a highly conserved component of the divisome among bacteria that have a cell wall, where it plays a central role in the assembly of early and late cell division proteins. Here, we describe the crystal structure of the major, periplasmic domain of FtsQ from Escherichia coli and Yersinia enterocolitica . The crystal structure reveals two domains; the α-domain has a striking similarity to polypeptide transport-associated (POTRA) domains and the C-terminal β-domain forms an extended β-sheet overlaid by two, slightly curved α-helices. Mutagenesis experiments demonstrate that two functions of FtsQ, localization and recruitment, occur in two separate domains. Proteins that localize FtsQ need the second β-strand of the POTRA domain and those that are recruited by FtsQ, like FtsL/FtsB, require the surface formed by the tip of the last α-helix and the two C-terminal β-strands. Both domains act together to accomplish the role of FtsQ in linking upstream and downstream cell division proteins within the divisome.     

Reference Values of Grip Strength Measured with a Jamar Dynamometer in 1526 Adults with Intellectual Disabilities and Compared to Adults without Intellectual Disability

Aim

The aim of this study was to investigate grip strength in a large sample of people with intellectual disabilities, to establish reference values for adults with intellectual disabilities (ID) and compare it to adults without intellectual disability.

Methods

This study analysed pooled baseline data from two independent studies for all 1526 adults with ID: Special Olympics Funfitness Spain (n = 801) and the Dutch cross-sectional study ‘Healthy aging and intellectual disabilities’ (n = 725).

Results

The grip strength result of people with ID across gender and age subgroups is presented with CI95% values from higher 25.5–31.0 kg in male younger to lower 4.3–21.6 kg in female older.

Conclusion

This study is the first to present grip strength results of a large sample of people with ID from 20–90 years of age. This study provides reference values for people with ID for use in clinical practice.     

Maturation of the Escherichia coli divisome occurs in two steps

Cell division proteins FtsZ (FtsA, ZipA, ZapA), FtsE/X, FtsK, FtsQ, FtsL/B, FtsW, PBP3, FtsN and AmiC localize at mid cell in Escherichia coli in an interdependent order as listed. To investigate whether this reflects a time dependent maturation of the divisome, the average cell age at which FtsZ, FtsQ, FtsW, PBP3 and FtsN arrive at their destination was determined by immuno- and GFP-fluorescence microscopy of steady state grown cells at a variety of growth rates. Consistently, a time delay of 14-21 min, depending on the growth rate, between Z-ring formation and the mid cell recruitment of proteins down stream of FtsK was found. We suggest a two-step model for bacterial division in which the Z-ring is involved in the switch from cylindrical to polar peptidoglycan synthesis, whereas the much later localizing cell division proteins are responsible for the modification of the envelope shape into that of two new poles.     

Predicting gene function through systematic analysis and quality assessment of high-throughput data

MOTIVATION: Determining gene function is an important challenge arising from the availability of whole genome sequences. Until recently, approaches based on sequence homology were the only high-throughput method for predicting gene function. Use of high-throughput generated experimental data sets for determining gene function has been limited for several reasons. RESULTS: Here a new approach is presented for integration of high-throughput data sets, leading to prediction of function based on relationships supported by multiple types and sources of data. This is achieved with a database containing 125 different high-throughput data sets describing phenotypes, cellular localizations, protein interactions and mRNA expression levels from Saccharomyces cerevisiae, using a bit-vector representation and information content-based ranking. The approach takes characteristic and qualitative differences between the data sets into account, is highly flexible, efficient and scalable. Database queries result in predictions for 543 uncharacterized genes, based on multiple functional relationships each supported by at least three types of experimental data. Some of these are experimentally verified, further demonstrating their reliability. The results also generate insights into the relative merits of different data types and provide a coherent framework for functional genomic datamining. AVAILABILITY: Free availability over the Internet. CONTACT: f.c.p.holstege@med.uu.nl SUPPLEMENTARY INFORMATION: http://www.genomics.med.uu.nl/pub/pk/comb_gen_network.     

Ouderen met een verstandelijke beperking verliezen veel zelfredzaamheid gedurende drie jaar: resultaten van de Gezond Ouder studie (GOUD)

The responsibilities for the care of a significant portion of the population with an intellectual disability (ID) were recently transferred from the government to the municipalities. It is therefore important that policymakers and care professionals know how much support this population needs in their daily life. Therefore, this study focuses on the decline in daily functioning of older adults with ID (≥50 years, n = 703) over 3 years, and if daily functioning is a predictor for all-cause mortality. Daily functioning was operationalized as basic and instrumental activities of daily living (ADL and IADL) and mobility. Fifty-five percent of the total group declined in ADL, 42?% in IADL, and 38?% in mobility. Thirty-nine percent of the participants with mild ID declined in ADL, 55?% in IADL, and 27?% in mobility. Poor daily functioning and mobility was a risk factor for all-cause mortality. This epidemiological study shows a clear decline in the daily functioning of older adults with intellectual disabilities over a 3-year follow-up period. Care providers should be aware of this decline and focus on maintaining as much independence as possible.     

Quinazolinone fungal efflux pump inhibitors. Part 3: (N-methyl)piperazine variants and pharmacokinetic optimization

Further structure-activity relationships of a novel series of fungal efflux pump inhibitors with respect to potentiation of the activity of fluconazole against strains of C. albicans and C. glabrata over-expressing ABC-type efflux pumps are systematically explored. Rat protein binding and pharmacokinetics of selected analogues are reported.