Effect of particulate antigenic stimulation or in vivo administration of interleukin-6 on the level of steroidogenic enzymes in adrenal glands and lymphoid tissues of mice with parallel alteration in endogenous inflammatory cytokine level

To study the effects of sheep red blood cells (SRBC), viable Escherichia coli inoculation and IL-6 administration on steroidogenesis, activities and expression of hydroxy steroid dehydrogenase enzymes (3βHSD and 17βHSD) were measured in lymphoid organs of control and infected mice after 3 weeks treatment. Serum testosterone and cytokine levels were also estimated. Reduced expression of 3βHSD4 was found in the spleen of treated groups as compared to control, whereas the 3βHSD4 expression was increased in the thymus and lymph gland after stimulation. Reduced serum testosterone level was observed after antigenic stimulation and also altered serum IL-12p70, TNF-α, IFN-γ, MCP-1 or IL-10 level. These studies provide the evidence of expression of 3βHSD4 enzyme in the murine lymphoid organs after particulate antigen stimulation along with a parallel alteration in endogenous cytokine level.     

Functional and structural characterization of the talin F0F1 domain

The globular head domain of talin, a large multi-domain cytoplasmic protein, is required for inside-out activation of the integrins, a family of heterodimeric transmembrane cell adhesion molecules. Talin head contains a FERM domain that is composed of F1, F2, and F3 subdomains. A F0 subdomain is located N-terminus to F1. The F3 contains a canonical phosphotyrosine binding (PTB) fold that directly interacts with the membrane proximal NPxY/F motif in the integrin β cytoplasmic tail. This interaction is stabilized by the F2 that interacts with the lipid head-groups of the plasma membrane. In comparison to F2 and F3, the properties of the F0F1 remains poorly characterized. Here, we showed that F0F1 is essential for talin-induced activation of integrin αLβ2 (LFA-1). F0F1 has a high content of β-sheet secondary structure, and it tends to homodimerize that may provide stability against proteolysis and chaotrope induced unfolding.     

External Mechanical Cues Reveal a Katanin-Independent Mechanism behind Auxin-Mediated Tissue Bending in Plants

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A new computational model to study mass inhomogeneity and hydrophobicity inhomogeneity in proteins

We propose a simple yet reliable computational framework that characterizes the differential mass and hydrophobicity distribution within structural classes of proteins. Radial partitioning of protein interior that could successfully distinguish the mass and hydrophobicity distribution patterns in extremophilic proteins from that in their structurally aligned mesophilic counterparts. Distance-dependent mass and hydrophobicity magnitudes could retrieve vital structural insights; needed to probe the hidden connections between packing, folding and stability within different structural classes of proteins, with causality. New computational markers; one, to represent the total mass content; other, related to hydrophobic centrality of proteins, are proposed as well. Results reveal that mass and hydrophobicity packing within extremophilic proteins is indeed more compact than that in their mesophilic counterparts. Analysis of structural constraints within them vindicate it. Total mass (and hydrophobicity) content is found to be maximum in α/β thermophilic proteins and minimum for the all-α mesophilic proteins. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

DNA G-quadruplexes for native mass spectrometry in potassium: a database of validated structures in electrospray-compatible conditions

G-quadruplex DNA structures have become attractive drug targets, and native mass spectrometry can provide detailed characterization of drug binding stoichiometry and affinity, potentially at high throughput. However, the G-quadruplex DNA polymorphism poses problems for interpreting ligand screening assays. In order to establish standardized MS-based screening assays, we studied 28 sequences with documented NMR structures in (usually ∼100 mM) potassium, and report here their circular dichroism (CD), melting temperature (T_m), NMR spectra and electrospray mass spectra in 1 mM KCl/100 mM trimethylammonium acetate. Based on these results, we make a short-list of sequences that adopt the same structure in the MS assay as reported by NMR, and provide recommendations on using them for MS-based assays. We also built an R-based open-source application to build and consult a database, wherein further sequences can be incorporated in the future. The application handles automatically most of the data processing, and allows generating custom figures and reports. The database is included in the g4dbr package (https://github.com/EricLarG4/g4dbr) and can be explored online (https://ericlarg4.github.io/G4_database.html).