From Small Peptides to Large Proteins against Alzheimer'sDisease

Alzheimer's disease (AD) is the most common neurodegenerative disorder in the elderly. The two cardinal neuropathological hallmarks of AD are the senile plaques, which are extracellular deposits mainly constituted by beta-amyloids, and neurofibrillary tangles formed by abnormally phosphorylated Tau (p-Tau) located in the cytoplasm of neurons. Although the research has made relevant progress in the management of the disease, the treatment is still lacking. Only symptomatic medications exist for the disease, and, in the meantime, laboratories worldwide are investigating disease-modifying treatments for AD. In the present review, results centered on the use of peptides of different sizes involved in AD are presented

Moringa oleifera Leaf Powder as Functional Additive in Cookies to Protect SH-SY5Y Cells

The aim of this work is the evaluation of the addition of Moringa leaf powder (MLP) in cookies in terms of antioxidant properties, dough processability and sensorial properties of the cookies. The total content of biophenols and flavonoids in MLP was detected and the identification of the bioactive molecules was performed by HPLC-ESI-TOF-MS measurements, before and after oven treatment at 180 ◦C for 20 min. After a preliminary evaluation of the MLP water soluble fraction (MLPsf) cytotoxicity, its protective effect against an oxidative injury induced in the SH-SY5Y cells was assessed. Data evidence that the bioactive molecules present in MLPsf are effective in preventing ROS production and in protecting neuronal cells against oxidative stress. Prototypes of cookies containing MLP in different concentrations were then produced and evaluated by a consumer panel. Selected doughs containing MLP were analysed to determine the total content of biophenols in the cookies after baking and their enrichment in terms of valuable chemical elements. The influence of MLP on the viscoelastic behaviour and morphology of the doughs was also assessed. Finally, the potential role in counteracting the insurgence of not treatable neurodegenerative pathologies of two main MLP components, glucomoringin and kaempferol derivatives, present also after the thermal treatment, was discussed

The molecular anatomy of human Hsp60 and its effects on Amyloid-β peptide

Heat Shock Protein 60 (HSP60) is ubiquitous and highly conserved, being present in eukaryotes and prokaryotes, including pathogens. This chaperonin is typically considered a mitochondrial protein but it is also found in other intracellular sites, extracellularly and in circulation. HSP60 is an indispensable component of the Chaperoning System and plays a key role in protein quality control, preventing off-pathway folding events and refolding misfolded proteins. This makes HSP60 a putative therapeutic agent for neurodegenerative diseases associated with aggregation of misfolded proteins, for example, Alzheimer’s Disease. We produced and purified recombinant human HSP60 and investigated the effects of its monomeric and tetradecameric forms onAmyloid-β aggregation. In addition, we induced oligomerization of HSP60 monomers by means of ATP. We measuredHSP60 stability in relation to degree of oligomerization. The structural stability of the HSP60 forms were also investigated by differential scanning calorimetry and isothermal titration calorimetry. The protein purified mainly appears in multimeric forms with a large fraction in dimers and monomers. We observed that Hsp60 is less stable in its monomeric form, but is more active in inhibiting the fibrillogenesis of beta amyloid peptide

Stable nanovesicles formed by intrinsically planar bilayers

Quatsome nanovesicles, formed through the self-assembly of cholesterol (CHOL) and cetyltrimethylammonium bromide (CTAB) in water, have shown long-term stability in terms of size and morphology, while at the same time exhibiting high CHOL-CTAB intermolecular binding energies. We hypothesize that CHOL/CTAB quatsomes are indeed thermodynamically stable nanovesicles, and investigate the mechanism underlying their formation.This work was supported by funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia. The production of quatsomes and part of their characterization has been performed by the ICTS “NANBIOSIS”, more specifically by the Biomaterial Processing and Nanostructuring Unit (U6), Unit of the CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN) located at the Institute of Materials Science of Barcelona (ICMAB-CSIC). ICMAB-CSIC acknowledges support from the MINECO through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-2015-0496 and CEX2019-000917-S). Authors acknowledge financial support from the Spanish Ministry of Science and Innovation through grants “MOL4BIO” (PID2019-105622RB-I00), “SimBioSoft” (PID2021-124297NB-C33) and the FUNFUTURE-FIP-2020 Severo Ochoa project, from Generalitat de Catalunya through grant 2017-SGR-918, from CSIC through grant 2019AEP133, and from the European Commission through the H2020 PHOENIX project (contract no. 953110). We acknowledge the support of the Israel scienceIsrael science Foundation, grant 1117/2016, and thank Dr. Inbal Ionita for her professional assistance in the cryo-TEM analysis. We thank Jannik Nedergaard Pedersen and Beatrice Plazzotta for help with the SAXS measurements. The simulations reported here were performed using the Cori Supercomputing facility of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

The Interplay between PolyQ and Protein Context Delays Aggregation by Forming a Reservoir of Protofibrils

Polyglutamine (polyQ) diseases are inherited neurodegenerative disorders caused by the expansion of CAG codon repeats, which code for polyQ in the corresponding gene products. These diseases are associated with the presence of amyloid-like protein aggregates, induced by polyQ expansion. It has been suggested that the soluble aggregates rather than the mature fibrillar aggregates are the toxic species, and that the aggregation properties of polyQ can be strongly modulated by the surrounding protein context. To assess the importance of the protein carrier in polyQ aggregation, we have studied the misfolding pathway and the kinetics of aggregation of polyQ of lengths above (Q41) and below (Q22) the pathological threshold fused to the well-characterized protein carrier glutathione S-transferase (GST). This protein, chosen as a model system, is per se able to misfold and aggregate irreversibly, thus mimicking the behaviour of domains of naturally occurring polyQ proteins. We prove that, while it is generally accepted that the aggregation kinetics of polyQ depend on its length and are faster for longer polyQ tracts, the presence of GST alters the polyQ aggregation pathway and reverses this trend. Aggregation occurs through formation of a reservoir of soluble intermediates whose populations and kinetic stabilities increase with polyQ length. Our results provide a new model that explains the toxicity of expanded polyQ proteins, in which the interplay between polyQ regions and other aggregation-prone domains plays a key role in determining the aggregation pathway

Minimalism in Radiation Synthesis of Biomedical Functional Nanogels

A scalable, single-step, synthetic approach for the manufacture of biocompatible, functionalized micro- and nanogels is presented. In particular, poly(N-vinyl pyrrolidone)-grafted-(aminopropyl)methacrylamide microgels and nanogels were generated through e-beam irradiation of PVP aqueous solutions in the presence of a primary amino-group-carrying monomer. Particles with different hydrodynamic diameters and surface charge densities were obtained at the variance of the irradiation conditions. Chemical structure was investigated by different spectroscopic techniques. Fluorescent variants were generated through fluorescein isothiocyanate attachment to the primary amino groups grafted to PVP, to both quantify the available functional groups for bioconjugation and follow nanogels localization in cell cultures. Finally, a model protein, bovine serum albumin, was conjugated to the nanogels to demonstrate the attachment of biologically relevant molecules for targeting purposes in drug delivery. The described approach provides a novel strategy to fabricate biohybrid nanogels with a very promising potential in nanomedicine

Intrinsic Disorder and Chaperon-Like Activity of Different Caseins

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Correlation between rheological propertiesm and limonene release in pectin gels using an electronic nose

Pectin gels at different polymer concentrations were used as matrices for the encapsulation of a volatile flavour (limonene). This provides a useful model system for studying the influence of the matrix viscoelastic properties on the flavour release towards the gel headspace. The electronic nose technique and principal component analysis (PCA), a multivariate data analysis, were used for detecting changes in the fingerprint of the released vapour as a function of pectin concentration. Samples with different composition were also studied by rheological measurements in order to discriminate the effects of polymer concentration on the gelation kinetics from those due to the addition of limonene and the detergent used to dissolve it.The combined approach, rheometry-electronic nose, allows obtaining a direct semi-quantitative correlation between the expected decrease of flavour release intensity and the increasing solid like character of the matrix due to trapping effect. In fact, the comparison of the viscoelastic properties for matrixes with and without the flavour, together with direct observation by optical microscopy, suggests that the release modulation is mainly due to interaction of the gelling pectin with the microemulsion of detergent and flavour.Fil: Monge, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Negri, Ricardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Giacomazza, Daniela. Consiglio Nazionale delle Ricerche; ItaliaFil: Bulone, Donatella. Consiglio Nazionale delle Ricerche; Itali

Temporal control of xyloglucan self-assembly by radiation-induced degradation

Xyloglucan is a natural polysaccharide present as storage material in seeds and structural materials in the primary cells walls of higher plants. Xyloglucan from tamarind seed is composed of B(1,4)-D-glucan backbone, partially substituted by a-(1,6)-linked xylose units, some of which are B-D-galactosylated at O-2. In its native form the polymer is water-soluble and forms gel in the presence of moderate amounts of alcohols. When a given fraction of galactosyl residues are removed, the polymer acquires the ability to form gels in aqueous solution at physiological temperatures, a property of great interest for biomedical/pharmaceutical applications. Gelation on increasing temperature can be ascribed to hydrophobic interactions that drive the system into a region of thermodynamic instability. In the highly concentrated regions generated by demixing, the dangling segments of polymeric chains "condensate" into additional intra- and inter molecular bonds forming a more compact structure. The drammatic viscosity increase prevents phase separation to occur and leads to gel formation. Gel morphology and properties are controlled by the relative rate of condensation and gelation, and they are both affected by the molecular weight distribution of the biopolymer. Gamma irradiation of the solid polymer in the form of a dry powder has been carried out to tailor the molecular weight of the polymer without significant alteration of its chemical structure. As a result, temperature induced gelation leads to gels with vaious degrees of structural order, from disordered porous networks for the non-irradiated system to a fairly ordered stack of thin membranes for the system irradiated at 20 kGy. Gamma irradiation of the polymer as a solid materials in the presence of different gaseous atmospheres and in aqueous solution have been carried out in the attempt to elucidate the radiation chemistry of xyloglucan