•The NMR spectrum of PB2 627 showed well dispersed signals.•Its signal intensity was inhomogeneous, suggesting structural fluctuations.•Glycine and L-α-alanine reduced structural fluctuations.•Glycine and L-α-alanine improved the quality of spectral data of NMR.The influenza A virus, which has an RNA genome, requires RNA-dependent RNA polymerase for transcription and replication. The polymerase is comprised of the subunits PA, PB1, and PB2. The C-terminal RNA-binding domain in PB2 contains lysine 627 (PB2 627), which is associated with pathogenicity and host range. However, the structure and molecular mechanism of PB2 627 in solution remain obscure. Here, we investigated PB2 627 in solution by nuclear magnetic resonance (NMR) and detected inhomogeneity in the intensities of backbone amide proton signals due to local fluctuations in structure. To characterize the effects of chemical chaperones on spectral data and improve the data quality, we tested 20 different additives, including L-arginine L-glutamate salt, (L-arginine)2SO4, glycerol, β-octylglucoside, 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate, Na2SO4, 1,5-diaminopentane, 1,4-diaminobutane, trehalose, sucrose, glycine, trimethylamine N-oxide, β-alanine, L-α-alanine, hydroxyectoine, betaine, L-proline, and non-detergent sulfobetaine 195, 201, and 256. We evaluated the quality of the resulting spectra by calculating the standard deviation and average of the ratio of signal intensities to noise level of amide peaks, as well as the ratio of the standard deviation to the average. NMR-profile analysis revealed diverse effects of additives on the dynamic properties of PB2 627. Based on such criteria, we found that small osmolytes such as glycine and L-α-alanine reduced structural fluctuations and improved the quality of spectral data, which is likely to facilitate a detailed NMR-based structural analysis. The methodology developed here may also be more generally useful for evaluating the effects of chemical chaperones on the structural integrity of proteins.

•Awa-ban tea suppressed blood glucose levels after administration of maltose in mice•Awa-ban tea suppressed blood glucose levels after administration of sucrose in mice•Awa-ban tea suppressed blood glucose levels after administration of glucose in mice•Awa-ban tea suppressed the area under the curve (AUC) of blood glucose by 72–83%•Awa-ban tea is an alternative functional beverage to prevent diabetesAwa-ban tea is a uniquely flavored, pickled and anaerobically fermented tea found only in the Tokushima prefecture in the Shikoku region of Japan. Diabetes is a major health problem worldwide. Here, we report that Awa-ban tea suppressed the increase in blood glucose levels after oral administration of maltose, sucrose, or glucose in mice (n = 9–54). Awa-ban tea suppressed the area under the curve (AUC) of blood glucose by 72–83%. Thus, we propose that Awa-ban tea can be used as an alternative functional beverage for diabetes prevention.

Swine-origin influenza A virus has caused pandemics throughout the world and influenza A is regarded as a serious global health issue. Hence, novel drugs that will target these viruses are very desirable. Influenza A expresses an RNA polymerase essential for its transcription and replication which comprises PA, PB1, and PB2 subunits. We identified potential novel anti-influenza agents from a screen of 34 synthesized phenethylphenylphthalimide analogs derived from thalidomide (PPT analogs). For this screen we used a PA endonuclease inhibition assay, a PB2 pathogenicity-determinant domain-binding assay, and an anti-influenza A virus assay. Three PPT analogs, PPT-65, PPT-66, and PPT-67, were found to both inhibit PA endonuclease activity and retard the growth of influenza A, suggesting a correlation between their activities. PPT-28 was also found to inhibit the growth of influenza A. These four analogs have a 3,4-dihydroxyphenethyl group in common. We also discuss the possibility that 3,4-dihydroxyphenethyl group flexibility may play an important functional role in PA endonuclease inhibition. Another analog harboring a dimethoxyphenethyl group, PPT-62, showed PB2 pathogenicity-determinant domain-binding activity, but did not inhibit the growth of the virus. Our present results indicate the utility of the PA endonuclease assay in the screening of anti-influenza drugs and are therefore useful for future strategies to develop novel anti-influenza A drugs and for mapping the function of the influenza A RNA polymerase subunits.

Stomach cancer has a high mortality rate in East Asia, and is strongly associated with Helicobacter pylori (H. pylori) infection. H.pylori is known to express chemokine genes in the gastric mucosa, chemokines that are important host immune factors facilitating inflammation and tumor growth. To investigate the mechanism of carcinogenesis in the stomach, it is essential to determine which molecule of H. pylori is involved in induction of chemokines, but this has remained unclear. We previously reported that a tumor necrosis factor-α (TNF-α) inducing protein (Tipα) secreted from H. pylori acts as a tumor promoter in stomach cancer development, and thus started to investigate whether Tipα is involved in induction of chemokine genes.Comprehensive gene expression analysis was conducted using DNA microarray and KeyMolnet analyses. The gene expression was quantitatively analyzed by real-time RT-PCR.Comprehensive and quantitative gene expression analyses revealed that Tipα induces gene expression of the chemokines Ccl2, Ccl7, Ccl20, Cxcl1, Cxcl2, Cxcl5 and Cxcl10 extensively and simultaneously in mouse stomach cancer cells, MGT-40. Tipα induced high levels of chemokine gene expression, whereas inactive deleted Tipα, del-Tipα, showed only marginal expression, suggesting a correlation between tumor promotion and chemokine gene expression by Tipα. MG-132, a proteasome inhibitor which represses NF-κB-activation, inhibited chemokine gene expressions.We report here that Tipα of H. pylori gene product is a strong inducer of chemokine gene expressions, providing a new model for stomach cancer development.