Material-specific binding peptides empower sustainable innovations in plant health, biocatalysis, medicine and microplastic quantification.

Material-binding peptides (MBPs) have emerged as a diverse and innovation-enabling class of peptides in applications such as plant-/human health, immobilization of catalysts, bioactive coatings, accelerated polymer degradation and analytics for micro-/nanoplastics quantification. Progress has been fuelled by recent advancements in protein engineering methodologies and advances in computational and analytical methodologies, which allow the design of, for instance, material-specific MBPs with fine-tuned binding strength for numerous demands in material science applications. A genetic or chemical conjugation of second (biological, chemical or physical property-changing) functionality to MBPs empowers the design of advanced (hybrid) materials, bioactive coatings and analytical tools. In this review, we provide a comprehensive overview comprising naturally occurring MBPs and their function in nature, binding properties of short man-made MBPs (<20 amino acids) mainly obtained from phage-display libraries, and medium-sized binding peptides (20-100 amino acids) that have been reported to bind to metals, polymers or other industrially produced materials. The goal of this review is to provide an in-depth understanding of molecular interactions between materials and material-specific binding peptides, and thereby empower the use of MBPs in material science applications. Protein engineering methodologies and selected examples to tailor MBPs toward applications in agriculture with a focus on plant health, biocatalysis, medicine and environmental monitoring serve as examples of the transformative power of MBPs for various industrial applications. An emphasis will be given to MBPs' role in detecting and quantifying microplastics in high throughput, distinguishing microplastics from other environmental particles, and thereby assisting to close an analytical gap in food safety and monitoring of environmental plastic pollution. In essence, this review aims to provide an overview among researchers from diverse disciplines in respect to material-(specific) binding of MBPs, protein engineering methodologies to tailor their properties to application demands, re-engineering for material science applications using MBPs, and thereby inspire researchers to employ MBPs in their research.

Plastibodies for multiplexed detection and sorting of microplastic particles in high-throughput.

Sensitive high-throughput analytic methodologies are needed to quantify microplastic particles (MPs) and thereby enable routine monitoring of MPs to ultimately secure animal, human, and environmental health. Here we report a multiplexed analytical and flow cytometry-based high-throughput methodology to quantify MPs in aqueous suspensions. The developed analytic MPs-quantification platform provides a sensitive as well as high-throughput detection of MPs that relies on the material binding peptide Liquid Chromatography Peak I (LCI) conjugated to Alexa-fluorophores (LCIF16C-AF488, LCIF16C-AF594, and LCIF16C-AF647). These fluorescent material-binding peptides (also termed plastibodies) were used to fluorescently label polystyrene MPs, whereas Alexa-fluorophores alone exhibited a negligible background fluorescence. Mixtures of polystyrene MPs that varied in size (500 nm to 5 µm) and varied in labeled populations were analyzed and sorted into distinct populations reaching sorting efficiencies >90 % for 1 × 106 sorted events. Finally, a multiplexed quantification and sorting with up to three plastibodies was successfully achieved to validate that the combination of plastibodies and flow cytometry is a powerful and generally applicable methodology for multiplexed analysis, quantification, and sorting of microplastic particles.

The Social Housing Crisis and the Barriers to Developing Dementia-Friendly Communities in Chile.

Interaction with living place and neighbourhood is one of the cornerstones for creating dementia-friendly communities (DFC). Chile has one of the largest proportions of older adults in Latin America and is currently facing an increase in the number of people with dementia. In this context, the Chilean government has launched a national strategy that involves actions in the health and social care system, including the promotion of DFC. From a multisectoral approach, social and environmental aspects involving engagement with local communities and access to social connections and services are directly related to urban policies. This perspective article focuses on urban aspects of social housing policy, such as placement, networks, affordability and the relationship between subsidy structure and adequate housing provision in a country with a qualitative housing deficit of around 1,200,000 units and where a large proportion of people with dementia and their families live in poverty. We identified several barriers to delivering appropriate environments for people living with dementia in relation to a two-fold problem: (a) the social housing subsidy displaces caregivers and/or older adults to satellite towns where social connections and access to services and urban equipment are lost; and (b) people resisting displacement live in overcrowded neighbourhoods where dementia is a common problem. In both scenarios, a detrimental environment and social conditions directly affect the quality of life of elderly people living with dementia and their caregivers.

Can constraint network analysis guide the identification phase of KnowVolution? A case study on improved thermostability of an endo-ß-glucanase.

Cellulases are industrially important enzymes, e.g., in the production of bioethanol, in pulp and paper industry, feedstock, and textile. Thermostability is often a prerequisite for high process stability and improving thermostability without affecting specific activities at lower temperatures is challenging and often time-consuming. Protein engineering strategies that combine experimental and computational are emerging in order to reduce experimental screening efforts and speed up enzyme engineering campaigns. Constraint Network Analysis (CNA) is a promising computational method that identifies beneficial positions in enzymes to improve thermostability. In this study, we compare CNA and directed evolution in the identification of beneficial positions in order to evaluate the potential of CNA in protein engineering campaigns (e.g., in the identification phase of KnowVolution). We engineered the industrially relevant endoglucanase EGLII from Penicillium verruculosum towards increased thermostability. From the CNA approach, six variants were obtained with an up to 2-fold improvement in thermostability. The overall experimental burden was reduced to 40% utilizing the CNA method in comparison to directed evolution. On a variant level, the success rate was similar for both strategies, with 0.27% and 0.18% improved variants in the epPCR and CNA-guided library, respectively. In essence, CNA is an effective method for identification of positions that improve thermostability.

Purification and characterization of two thermostable xylanases from a halotolerant Bacillus sp. Asc6BA isolated from Salar de Ascotán, Atacama Desert.

Two extracellular xylanases, denominated X2 and X3, were purified and characterized from the halotolerant bacterium Bacillus sp. Asc6BA isolated from "Salar de Ascotán" in the Atacama Desert. Xylanases were purified by anion exchange, cation exchange and size exclusion liquid chromatography. Xylanase X2 and X3 were purified ~ 690-fold and ~ 629-fold, respectively, compared to the concentrated extracellular fraction with a final specific activity of 169 and 154 u mg-1, respectively. Optimal conditions of pH and temperature of xylanolytic activity were 6.0 and 60 °C for X2 and 7.0 and 60 °C for X3. Half-life of X2 xylanase was 30 min at 50 °C, while X3 xylanase was remarkably more thermostable, retaining more than 70% of its activity after 32 h of incubation at 50 °C. X2 exhibited Km, Vmax and kcat values of 7.17 mg mL-1, 1.28 mM min-1 mg-1 and 425.33 s-1, respectively. X3 exhibited Km, Vmax and kcat values of 6.00 mg mL-1, 19.25 mM min-1 mg-1 and 82,515 s-1, respectively. In addition to their thermal stabilities, these enzymes were shown to be resistant to freeze-drying. These stability properties, in addition to the ability of these enzymes to be active in a wide range of temperatures and pHs, make these xylanases good candidates for industrial applications.

Engineering Robust Cellulases for Tailored Lignocellulosic Degradation Cocktails.

Lignocellulosic biomass is a most promising feedstock in the production of second-generation biofuels. Efficient degradation of lignocellulosic biomass requires a synergistic action of several cellulases and hemicellulases. Cellulases depolymerize cellulose, the main polymer of the lignocellulosic biomass, to its building blocks. The production of cellulase cocktails has been widely explored, however, there are still some main challenges that enzymes need to overcome in order to develop a sustainable production of bioethanol. The main challenges include low activity, product inhibition, and the need to perform fine-tuning of a cellulase cocktail for each type of biomass. Protein engineering and directed evolution are powerful technologies to improve enzyme properties such as increased activity, decreased product inhibition, increased thermal stability, improved performance in non-conventional media, and pH stability, which will lead to a production of more efficient cocktails. In this review, we focus on recent advances in cellulase cocktail production, its current challenges, protein engineering as an efficient strategy to engineer cellulases, and our view on future prospects in the generation of tailored cellulases for biofuel production.

Hipertensión pulmonar reversible y derrame pericárdico severo secundario a uso dasatinib: Reporte de caso / Reversible pulmonary hypertension and pericardial effusion secondary to use of dasatinib. Case report

Dasatinib es un potente inhibidor de la tinosina kinasa utilizado como tratamiento de segunda línea en pacientes con leucemia mieloide crónica, especialmente cuando se desarrolla resistencia o algún tipo de intolerancia a imatinib. A pesar de la aparente selectividad, pueden producirse efectos secundarios significativos. Los derrames pericárdicos son complicaciones frecuentes, que usualmente necesitan reducir la dosis o discontinuar el tratamiento. Por otro lado, la hipertensión pulmonar es un efecto adverso poco frecuente que puede aparecer a los 8 meses del inicio de la terapia. A continuación se presenta el caso de un paciente de 82 años que desarrolla derrame pericárdico crónico e hipertensión pulmonar reversible tras reducción de la dosis de Dasatinib.

Dasatinib is a potent tyrosine kinase inhibitor used as second line treatment for patients with chronic myeloid leukemia, particularly when resistance or some type of intolerance to imatinib has built up. Despite its apparent selectivity it can have significant side effects. Pericardial effusions are frequent complications and usually require dose reduction or treatment discontinuation. On the other hand, pulmonary hypertension is an infrequent side effect which may appear 8 months after initiating treatment. In the following we present the case of an 82 year old who developed a chronic pericardial effusion and pulmonary hypertension which were reversed upon reducing the dasatinib dose.

The type VI secretion system encoded in Salmonella pathogenicity island 19 is required for Salmonella enterica serotype Gallinarum survival within infected macrophages.

Salmonella enterica serotype Gallinarum is the causative agent of fowl typhoid, a disease characterized by high morbidity and mortality that causes major economic losses in poultry production. We have reported that S. Gallinarum harbors a type VI secretion system (T6SS) encoded in Salmonella pathogenicity island 19 (SPI-19) that is required for efficient colonization of chicks. In the present study, we aimed to characterize the SPI-19 T6SS functionality and to investigate the mechanisms behind the phenotypes previously observed in vivo. Expression analyses revealed that SPI-19 T6SS core components are expressed and produced under in vitro bacterial growth conditions. However, secretion of the structural/secreted components Hcp1, Hcp2, and VgrG to the culture medium could not be determined, suggesting that additional signals are required for T6SS-dependent secretion of these proteins. In vitro bacterial competition assays failed to demonstrate a role for SPI-19 T6SS in interbacterial killing. In contrast, cell culture experiments with murine and avian macrophages (RAW264.7 and HD11, respectively) revealed production of a green fluorescent protein-tagged version of VgrG soon after Salmonella uptake. Furthermore, infection of RAW264.7 and HD11 macrophages with deletion mutants of SPI-19 or strains with genes encoding specific T6SS core components (clpV and vgrG) revealed that SPI-19 T6SS contributes to S. Gallinarum survival within macrophages at 20 h postuptake. SPI-19 T6SS function was not linked to Salmonella-induced cytotoxicity or cell death of infected macrophages, as has been described for other T6SS. Our data indicate that SPI-19 T6SS corresponds to a novel tool used by Salmonella to survive within host cells.