Application of Hansch’s Model to Capsaicinoids and Capsinoids: A Study Using the Quantitative Structure−Activity Relationship. A Novel Method for the Synthesis of Capsinoids

We describe a synthetic approach for two families of compounds, the capsaicinoids and capsinoids, as part of a study of the quantitative relationship between structure and activity

Identifying the electronic character and role of the Mn states in the valence band of (Ga,Mn)As

We report high-resolution hard x-ray photoemission spectroscopy results on (Ga,Mn)As films as a function of Mn doping. Supported by theoretical calculations we identify, over the entire 1% to 13% Mn doping range, the electronic character of the states near the top of the valence band. Magnetization and temperature dependent core-level photoemission spectra reveal how the delocalized character of the Mn states enables the bulk ferromagnetic properties of (Ga,Mn)As.Comment: prl submitte

High Distribution of CD40 and TRAF2 in Th40 T Cell Rafts Leads to Preferential Survival of this Auto-Aggressive Population in Autoimmunity

CD40-CD154 interactions have proven critical in autoimmunity, with the identification of CD4(lo)CD40(+) T cells (Th40 cells) as harboring an autoaggressive T cell population shedding new insights into those disease processes. Th40 cells are present at contained levels in non-autoimmune individuals but are significantly expanded in autoimmunity. Th40 cells are necessary and sufficient in transferring type 1 diabetes in mouse models. However, little is known about CD40 signaling in T cells and whether there are differences in that signaling and subsequent outcome depending on disease conditions. When CD40 is engaged, CD40 and TNF-receptor associated factors, TRAFs, become associated with lipid raft microdomains. Dysregulation of T cell homeostasis is emerging as a major contributor to autoimmune disease and thwarted apoptosis is key in breaking homeostasis.Cells were sorted into CD4(hi) and CD4(lo) (Th40 cells) then treated and assayed either as whole or fractionated cell lysates. Protein expression was assayed by western blot and Nf-kappaB DNA-binding activity by electrophoretic mobility shifts. We demonstrate here that autoimmune NOD Th40 cells have drastically exaggerated expression of CD40 on a per-cell-basis compared to non-autoimmune BALB/c. Immediately ex-vivo, untreated Th40 cells from NOD mice have high levels of CD40 and TRAF2 associated with the raft microdomain while Th40 cells from NOR and BALB/c mice do not. CD40 engagement of Th40 cells induces Nf-kappaB DNA-binding activity and anti-apoptotic Bcl-X(L) expression in all three mouse strains. However, only in NOD Th40 cells is anti-apoptotic cFLIP(p43) induced which leads to preferential survival and proliferation. Importantly, CD40 engagement rescues NOD Th40 cells from Fas-induced death.CD40 may act as a switch between life and death promoting signals and NOD Th40 cells are poised for survival via this switch. This may explain how they expand in autoimmunity to thwart T cell homeostasis

Proteome-Wide Analysis of Single-Nucleotide Variations in the N-Glycosylation Sequon of Human Genes

N-linked glycosylation is one of the most frequent post-translational modifications of proteins with a profound impact on their biological function. Besides other functions, N-linked glycosylation assists in protein folding, determines protein orientation at the cell surface, or protects proteins from proteases. The N-linked glycans attach to asparagines in the sequence context Asn-X-Ser/Thr, where X is any amino acid except proline. Any variation (e.g. non-synonymous single nucleotide polymorphism or mutation) that abolishes the N-glycosylation sequence motif will lead to the loss of a glycosylation site. On the other hand, variations causing a substitution that creates a new N-glycosylation sequence motif can result in the gain of glycosylation. Although the general importance of glycosylation is well known and acknowledged, the effect of variation on the actual glycoproteome of an organism is still mostly unknown. In this study, we focus on a comprehensive analysis of non-synonymous single nucleotide variations (nsSNV) that lead to either loss or gain of the N-glycosylation motif. We find that 1091 proteins have modified N-glycosylation sequons due to nsSNVs in the genome. Based on analysis of proteins that have a solved 3D structure at the site of variation, we find that 48% of the variations that lead to changes in glycosylation sites occur at the loop and bend regions of the proteins. Pathway and function enrichment analysis show that a significant number of proteins that gained or lost the glycosylation motif are involved in kinase activity, immune response, and blood coagulation. A structure-function analysis of a blood coagulation protein, antithrombin III and a protease, cathepsin D, showcases how a comprehensive study followed by structural analysis can help better understand the functional impact of the nsSNVs

The lactose operon from Lactobacillus casei is involved in the transport and metabolism of the human milk oligosaccharide core-2 N-acetyllactosamine

The lactose operon (lacTEGF) from Lactobacillus casei strain BL23 has been previously studied. The lacT gene codes for a transcriptional antiterminator, lacE and lacF for the lactose-specific phosphoenolpyruvate: phosphotransferase system (PTSLac) EIICB and EIIA domains, respectively, and lacG for the phospho-β-galactosidase. In this work, we have shown that L. casei is able to metabolize N-acetyllactosamine (LacNAc), a disaccharide present at human milk and intestinal mucosa. The mutant strains BL153 (lacE) and BL155 (lacF) were defective in LacNAc utilization, indicating that the EIICB and EIIA of the PTSLac are involved in the uptake of LacNAc in addition to lactose. Inactivation of lacG abolishes the growth of L. casei in both disaccharides and analysis of LacG activity showed a high selectivity toward phosphorylated compounds, suggesting that LacG is necessary for the hydrolysis of the intracellular phosphorylated lactose and LacNAc. L. casei (lacAB) strain deficient in galactose-6P isomerase showed a growth rate in lactose (0.0293 ± 0.0014 h-1) and in LacNAc (0.0307 ± 0.0009 h-1) significantly lower than the wild-type (0.1010 ± 0.0006 h-1 and 0.0522 ± 0.0005 h-1, respectively), indicating that their galactose moiety is catabolized through the tagatose-6P pathway. Transcriptional analysis showed induction levels of the lac genes ranged from 130 to 320-fold in LacNAc and from 100 to 200-fold in lactose, compared to cells growing in glucose