Diffraction anisotropy and paired refinement: crystal structure of H33, a protein binder to interleukin 10.

Binder H33 is a small protein binder engineered by ribosome display to bind human interleukin 10. Crystals of binder H33 display severe diffraction anisotropy. A set of data files with correction for diffraction anisotropy based on different local signal-to-noise ratios was prepared. Paired refinement was used to find the optimal anisotropic high-resolution diffraction limit of the data: 3.13-2.47 Å. The structure of binder H33 belongs to the 2% of crystal structures with the highest solvent content in the Protein Data Bank.

Regulation of IL-24/IL-20R2 complex formation using photocaged tyrosines and UV light.

Human interleukin 24 (IL-24) is a multifunctional cytokine that represents an important target for autoimmune diseases and cancer. Since the biological functions of IL-24 depend on interactions with membrane receptors, on-demand regulation of the affinity between IL-24 and its cognate partners offers exciting possibilities in basic research and may have applications in therapy. As a proof-of-concept, we developed a strategy based on recombinant soluble protein variants and genetic code expansion technology to photocontrol the binding between IL-24 and one of its receptors, IL-20R2. Screening of non-canonical ortho-nitrobenzyl-tyrosine (NBY) residues introduced at several positions in both partners was done by a combination of biophysical and cell signaling assays. We identified one position for installing NBY, tyrosine70 of IL-20R2, which results in clear impairment of heterocomplex assembly in the dark. Irradiation with 365-nm light leads to decaging and reconstitutes the native tyrosine of the receptor that can then associate with IL-24. Photocaged IL-20R2 may be useful for the spatiotemporal control of the JAK/STAT phosphorylation cascade.

Protein Binder (ProBi) as a New Class of Structurally Robust Non-Antibody Protein Scaffold for Directed Evolution.

Engineered small non-antibody protein scaffolds are a promising alternative to antibodies and are especially attractive for use in protein therapeutics and diagnostics. The advantages include smaller size and a more robust, single-domain structural framework with a defined binding surface amenable to mutation. This calls for a more systematic approach in designing new scaffolds suitable for use in one or more methods of directed evolution. We hereby describe a process based on an analysis of protein structures from the Protein Data Bank and their experimental examination. The candidate protein scaffolds were subjected to a thorough screening including computational evaluation of the mutability, and experimental determination of their expression yield in E. coli, solubility, and thermostability. In the next step, we examined several variants of the candidate scaffolds including their wild types and alanine mutants. We proved the applicability of this systematic procedure by selecting a monomeric single-domain human protein with a fold different from previously known scaffolds. The newly developed scaffold, called ProBi (Protein Binder), contains two independently mutable surface patches. We demonstrated its functionality by training it as a binder against human interleukin-10, a medically important cytokine. The procedure yielded scaffold-related variants with nanomolar affinity.

Recycling drinking water treatment sludge into eco-concrete blocks with CO2 curing: Durability and leachability.

Drinking water treatment sludge (DWTS) can be recycled into low-strength concrete blocks for construction use. The sodium sulfate resistance and leaching behaviours of the DWTS-derived blocks are investigated in this study. The experimental results show that the addition of DWTS degrades the sodium sulfate resistance of the concrete blocks, however CO2 curing compensates for such property, especially in the case of blocks incorporating 30% DWTS. The improvement can be attributed to the formation of crystalline CaCO3 during CO2 curing for microstructure refinement evidenced by X-ray Computed Tomography and Scanning Electron Microscopy. Leaching analyses show that Cu and Al concentrations increased with increasing DWTS content, and CO2 curing adversely increased the leachability of metals due to the decrease of pH, especially at early leaching stage. Nevertheless, the total leaching concentrations of Cu and Al after 60-day test is far below the prescribed limitations, regardless of samples subject to air curing or CO2 curing. In summary, sludge-derived blocks exposed to CO2 curing are safe and behave well in aggressive environments. Therefore, this study showcases a green technology that successfully recycling DWTS into value-added and durable concrete blocks with low environmental impacts.

Utilization of drinking water treatment sludge in concrete paving blocks: Microstructural analysis, durability and leaching properties.

The management of abundant drinking water treatment sludge (DWTS) in landfill remains an important issue. The reuse of DWTS as construction material could contribute to the development of greener concrete product and to mitigating the detrimental environment effect from excessive production of DWTS. This paper investigates the potential of using DWTS as sand replacement in Concrete Paving Blocks (CPB). Five CPB mixtures were designed and the replacement ratios of sand by DWTS were 0%, 5%, 10%, 15%, and 20%, by weight. Properties of CPB such as compressive strength, water absorption, abrasion resistance, sulfate attack and metal leachability were determined. The results indicated that above 10% of DWTS, the replacement was detrimental to such properties of the CPB. Microstructure analysis proved the addition of DWTS could result in ettringite formation and the interfacial transition zone (ITZ) between the cement matrix and DWTS was more porous than that of sand. In addition, the metal leachability test of CPB demonstrated that the addition of high-copper DWTS into CPB was safe.

Crystal structure of human interferon-γ receptor 2 reveals the structural basis for receptor specificity.

Interferon-γ receptor 2 is a cell-surface receptor that is required for interferon-γ signalling and therefore plays a critical immunoregulatory role in innate and adaptive immunity against viral and also bacterial and protozoal infections. A crystal structure of the extracellular part of human interferon-γ receptor 2 (IFNγR2) was solved by molecular replacement at 1.8 Šresolution. Similar to other class 2 receptors, IFNγR2 has two fibronectin type III domains. The characteristic structural features of IFNγR2 are concentrated in its N-terminal domain: an extensive π-cation motif of stacked residues KWRWRH, a NAG-W-NAG sandwich (where NAG stands for N-acetyl-D-glucosamine) and finally a helix formed by residues 78-85, which is unique among class 2 receptors. Mass spectrometry and mutational analyses showed the importance of N-linked glycosylation to the stability of the protein and confirmed the presence of two disulfide bonds. Structure-based bioinformatic analysis revealed independent evolutionary behaviour of both receptor domains and, together with multiple sequence alignment, identified putative binding sites for interferon-γ and receptor 1, the ligands of IFNγR2.

Human rights, transitional justice, public health and social reconstruction.

Mass violence, armed conflict, genocide, and complex humanitarian emergencies continue to create major social and public health disasters at the dawn of the 21st Century. Transitional justice, a set of policies designed to address the effects of war on traumatized communities and bring justice, lies at the nexus of public health, conflict, and social reconstruction. Despite the paucity of empirical evidence, advocates of transitional justice have claimed that it can alleviate the effects of trauma, deter future violence, and bring about social reconstruction in war-affected communities. Empirical evidence--including new data and analyses presented in this article--suggests a link between trauma, mental health and attitudes towards and responses to transitional justice programs, but there has been little theoretical discussion about the intersection between public health and transitional justice, and even less empirical research to generate discussion between these two fields. Yet, public health professionals have an important role to play in assessing the impact of transitional justice on communities affected by mass violence. In this paper, we offer a conceptual model for future research that seeks to examine the relationship between transitional justice programs and their potential value to the fields of medicine and public health and discuss the methodological issues and challenges to a comprehensive evaluation of this relationship. To illustrate the discussion, we examine new data and analyses from two cases of contemporary conflicts, eastern Democratic Republic of Congo (DRC) and northern Uganda.