Studies of Hemicellulolytic Enzymes of Bacillus subtilis

Many strains of Bacillus subtilis were found to secrete several hemicellulolytic enzymes such as arabinoxylanase, galactomannanase, arabinogalactanase, etc. Chemical and enzymatic properties of certain strains of the bacterium were comparatively investigated. An arabinogalactanase was purified and obtained in a crystalline state. Its molecular weight and isoelectric point were estimated to be 3.7×10⁴ and 8.39, respectively. The enzyme showed an optimal pH for reactions at 6.0, and was stable in a pH range of 5.0 to 9.5 at 30°C. It required no metallic ions for its activity and hydrolyzed soybean arabinogalactan, forming galactobiose as the main product. No liberation of arabinose was observed in the hydrolysate. Also, the enzyme did not attack coffee bean arabinogalactan. Some implications of the experimental results are discussed.     

A protein-protein interaction in magnetosomes: TPR protein MamA interacts with an Mms6 protein

Magnetosomes are membrane-enveloped bacterial organelles containing nano-sized magnetic particles, and function as a cellular magnetic sensor, which assist the cells to navigate and swim along the geomagnetic field. Localized with each magnetosome is a suite of proteins involved in the synthesis, maintenance and functionalization of the organelle, however the detailed molecular organization of the proteins in magnetosomes is unresolved. MamA is one of the most abundant magnetosome-associated proteins and is anchored to the magnetosome vesicles through protein-protein interactions, but the identity of the protein that interacts with MamA is undetermined. In this study, we found that MamA binds to a magnetosome membrane protein Mms6. Two different molecular masses of Mms6, 14.5-kDa and 6.0-kDa, were associated with the magnetosomes. Using affinity chromatography, we identified that the 14.5-kDa Mms6 interacts with MamA, and the interaction was further confirmed by pull-down, immunoprecipitation and size-exclusion chromatography assays. Prior to this, Mms6 was assumed to be strictly involved with biomineralizing magnetite; however, these results suggest that Mms6 has an additional responsibility, binding to MamA.     

Structure-activity relationship studies of Bz amide-containing α-GalCer derivatives as natural killer T cell modulators

Abstract

CD1d is a non-polymorphic antigen-presenting glycoprotein that recognizes glycolipids as ligands. Ligands bind to the hydrophobic grooves of CD1d, and the resulting ligand-CD1d complexes activate natural killer T (NKT) cells by means of T cell receptor recognition, leading to the secretion of various cytokines. However, details of the ligand recognition mechanism of a large hydrophobic ligand binding pocket and the relationship between cytokine induction and ligand structure are unclear. We report the synthesis of α-GalCer derivatives containing a Bz amide group having various substituting groups in the ceramide moiety, and the analysis of the structure-activity relationships. The assays reveal that the Bz amide-containing CD1d ligands function as NKT cell modulators displaying Th2 cytokine biasing responses. Furthermore, molecular dynamics simulation studies suggest that the phenyl groups can interact with the aromatic amino acid residues in the lipid binding pocket of CD1d.     

Environmental analysis of packaging‐derived changes in food production and consumer behavior

This study analyzed the environmental impacts of packaging‐derived changes in food production and consumer behavior to assist packaging designers in making environmentally conscious decisions. Packaging can be functionalized to prevent food loss and waste (FLW), for example, extending the expiration date and apportioning the package size, but it can generate additional environmental impacts from changes in food and packaging production. Previous studies assessed additional impacts from packaging production; however, the effects of packaging functionalization are yet to be connected with food production and consumer behavior. To examine the effect of functionalization on these aspects, we analyzed packaging‐derived changes in food production for milk and cabbage products. The case study compared products with functionalized packaging that permits a longer expiration date or a smaller portion size to their base‐case products. Our results showed that the packaging‐derived changes increased the global warming potential (GWP) of food production more than other processes did. Thus, changes in food production weakened the effectiveness of the packaging functionalization to decrease the GWP. Moreover, the analysis of consumer behavior scenarios showed that consumers’ perception of the expiration date decisively influences the effectiveness of packaging functionalization. When consumers discarded food after the expiration date, provided they consumed in small quantities, the packaging functionalization reduced FLW. From the scenario analysis, we identified appropriate combinations of packaging functionalization and consumer behaviors to effectively decrease total GWP. With our expanded analysis, packaging designers can understand the effectiveness of their decisions on the product life cycle in reducing FLW and environmental impacts.     

Personalized medicine and proteomics: lessons from non-small cell lung cancer

Personalized medicine allows the selection of treatments best suited to an individual patient and disease phenotype. To implement personalized medicine, effective tests predictive of response to treatment or susceptibility to adverse events are needed, and to develop a personalized medicine test, both high quality samples and reliable data are required. We review key features of state-of-the-art proteomic profiling and introduce further analytic developments to build a proteomic toolkit for use in personalized medicine approaches. The combination of novel analytical approaches in proteomic data generation, alignment and comparison permit translation of identified biomarkers into practical assays. We further propose an expanded statistical analysis to understand the sources of variability between individuals in terms of both protein expression and clinical variables and utilize this understanding in a predictive test.     

Overlapping two genes in human DNA: a salivary amylase gene overlaps with a gamma-actin pseudogene that carries an integrated human endogenous retroviral DNA

The human salivary amylase gene (amy1), consisting of eleven exons, is expressed in the salivary gland and in some amylase-producing tumors. Its uppermost exon and the following intron, along with the 5'-flanking region of this gene, are shown to be superimposed with a gamma-actin pseudogene sequence, a portion of which is transcribed into salivary amylase mRNA and another portion of which serves as a promoter for the amy1 gene. In the further upstream region, the gamma-actin pseudogene sequence is interrupted by a human endogenous retroviral nucleotide sequence.