300 research outputs found

    Unraveling Binding Effects of Cobalt(II) Sepulchrate with the Monooxygenase P450 BM-3 Heme Domain Using Molecular Dynamics Simulations

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    One of the major limitations to exploit enzymes in industrial processes is their dependence on expensive reduction equivalents like NADPH to drive their catalytic cycle. Soluble electron transfer (ET) mediators like Cobalt(II)Sepulchrate have been proposed as a cost-effective alternative to shuttle electrons between an inexpensive electron source and enzyme redox center. The interactions of these molecules with enzymes are not elucidated at molecular level yet. Herein, molecular dynamics simulations are performed to understand the binding and ET mechanism of the Cobalt(II)Sepulchrate with the heme domain of cytochrome P450BM-3. The study provides a detailed map of ET mediator binding sites on protein surface that resulted prevalently composed by Asp and Glu amino acids. The Cobalt(II)Sepulchrate do not show a preferential binding to these sites. However, among the observed binding sites, only few of them provide efficient ET pathways to heme iron. The results of this study can be used to improve the ET mediator efficiency of the enzyme for possible biotechnological applications

    Structure, dynamics, and function of the monooxygenase P450 BM-3: insights from computer simulations studies

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    The monooxygenase P450 BM-3 is a NADPH-dependent fatty acid hydroxylase enzyme isolated from soil bacterium Bacillus megaterium. As a pivotal member of cytochrome P450 superfamily, it has been intensely studied for the comprehension of structure-dynamics-function relationships in this class of enzymes. In addition, due to its peculiar properties, it is also a promising enzyme for biochemical and biomedical applications. However, despite the efforts, the full understanding of the enzyme structure and dynamics is not yet achieved. Computational studies, particularly molecular dynamics (MD) simulations, have importantly contributed to this endeavor by providing new insights at an atomic level regarding the correlations between structure, dynamics, and function of the protein. This topical review summarizes computational studies based on MD simulations of the cytochrome P450 BM-3 and gives an outlook on future directions

    Fgf20 governs formation of primary and secondary dermal condensations in developing hair follicles

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    In hair follicle development, a placode-derived signal is believed to induce formation of the dermal condensation, an essential component of ectodermal organs. However, the identity of this signal is unknown. Furthermore, although induction and patterning of hair follicles are intimately linked, it is not known whether the mesenchymal condensation is necessary for inducing the initial epithelial pattern. Here, we show that fibroblast growth factor 20 (Fgf20) is expressed in hair placodes and is induced by and functions downstream from epithelial ectodysplasin (Eda)/Edar and Wnt/β-Catenin signaling to initiate formation of the underlying dermal condensation. Fgf20 governs formation of primary and secondary dermal condensations in developing hair follicles and subsequent formation of guard, awl, and auchene hairs. Although primary dermal condensations are absent in Fgf20 mutant mice, a regular array of hair placodes is formed, demonstrating that the epithelial patterning process is independent of known histological and molecular markers of underlying mesenchymal patterns during the initial stages of hair follicle development

    Site-specific perturbations of alpha-synuclein fibril structure by the Parkinson's disease associated mutations A53T and E46K.

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    PMCID: PMC3591419This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Parkinson's disease (PD) is pathologically characterized by the presence of Lewy bodies (LBs) in dopaminergic neurons of the substantia nigra. These intracellular inclusions are largely composed of misfolded α-synuclein (AS), a neuronal protein that is abundant in the vertebrate brain. Point mutations in AS are associated with rare, early-onset forms of PD, although aggregation of the wild-type (WT) protein is observed in the more common sporadic forms of the disease. Here, we employed multidimensional solid-state NMR experiments to assess A53T and E46K mutant fibrils, in comparison to our recent description of WT AS fibrils. We made de novo chemical shift assignments for the mutants, and used these chemical shifts to empirically determine secondary structures. We observe significant perturbations in secondary structure throughout the fibril core for the E46K fibril, while the A53T fibril exhibits more localized perturbations near the mutation site. Overall, these results demonstrate that the secondary structure of A53T has some small differences from the WT and the secondary structure of E46K has significant differences, which may alter the overall structural arrangement of the fibrils

    Stress factors in primary packaging, transportation and handling of protein drug products and their impact on product quality

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    Protein-based biologic drugs encounter a variety of stress factors during drug substance (DS) and drug product (DP) manufacturing, and the subsequent steps that result in clinical administration by the end user. This article is the third in a series of commentaries on these stress factors and their effect on biotherapeutics. It focuses on assessing the potential negative impact from primary packaging, transportation, and handling on the quality of the DP. The risk factors include ingress of hazardous materials such as oxidizing residuals from the sterilization process, delamination- or rubber stopper-derived particles, silicone oil droplets, and leachables into the formulation, as well as surface interactions between the protein and packaging materials, all of which may cause protein degradation. The type of primary packaging container used (such as vials and prefilled syringes) may substantially influence the impact of transportation and handling stresses on DP Critical Quality Attributes (CQAs). Mitigations via process development and robustness studies as well as control strategies for DP CQAs are discussed, along with current industry best practices for scale-down and in-use stability studies. We conclude that more research is needed on postproduction transportation and handling practices and their implications for protein DP quality.Drug Delivery Technolog

    Randomised evaluation of the Italian medicines use review provided by community pharmacists using asthma as a model (RE I-MUR)

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    Background The Italian Ministry of Health decided to introduce community professional services in 2010. This trial provides an opportunity to evaluate the outcomes of a new professional pharmacy service: Italian Medicines Use Review (I-MUR) aimed at reducing the severity of asthma and its associated costs. Methods/Design This is a cluster randomised controlled trial of the I-MUR service. Data will be collected over time before, during and after pharmacists’ intervention. Fifteen Italian regions will be involved and it is aimed to recruit 360 community pharmacists and 1800 patients. Each pharmacist will receive training in medicines use review, recruit five patients, administer the Asthma Control Test and provide the I-MUR service. Pharmacists will be allocated to different groups, one group will be trained in and provide the I-MUR service immediately after completion of the baseline ACT score, the other group will receive training in the I-MUR and provide this service three months later. Group allocation will be random, after stratification by region of Italy. The I-MUR service will involve gathering data following each patient consultation including demographic details, patients regular medications, including those used for asthma, their attitude towards their medications and self-reported adherence to treatments. In addition, pharmacists will identify and record pharmaceutical care issues and any advice given to patients during the I-MUR, or recommendations given to doctors. Pharmacists will upload trial data onto a web platform for analysis. The primary outcome measure is the severity of asthma before, during and after the I-MUR assessed using the Asthma Control Test score. Secondary measures: number of all active ingredients used by patients during and after the I-MUR, number of pharmaceutical care issues identified during the I-MUR, patients’ self-reported adherence to asthma medication during and after the I-MUR, healthcare costs based on the severity of asthma, before, during and after the I-MUR service provision. Discussion This study has been developed because of the need for a new way of working for pharmacists and pharmacies; it is the first trial of any community pharmacy-based pharmaceutical care intervention in Italy. The results will inform future policy and practice in Italian community pharmacy. Trial registration number ISRCTN72438848. Keywords Asthma – Medicines use review – Cluster randomised controlled trial (RCT) – Community pharmac

    The Role of Alpha-Synuclein Oligomerization and Aggregation in Cellular and Animal Models of Parkinson’s Disease

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    α-synuclein (α-syn) is a synaptic protein in which four mutations (A53T, A30P, E46K and gene triplication) have been found to cause an autosomal dominant form of Parkinson’s disease (PD). It is also the major component of intraneuronal protein aggregates, designated as Lewy bodies (LBs), a prominent pathological hallmark of PD. How α-syn contributes to LB formation and PD is still not well-understood. It has been proposed that aggregation of α-syn contributes to the formation of LBs, which then leads to neurodegeneration in PD. However, studies have also suggested that aggregates formation is a protective mechanism against more toxic α-syn oligomers. In this study, we have generated α-syn mutants that have increased propensity to form aggregates by attaching a CL1 peptide to the C-terminal of α-syn. Data from our cellular study suggest an inverse correlation between cell viability and the amount of α-syn aggregates formed in the cells. In addition, our animal model of PD indicates that attachment of CL1 to α-syn enhanced its toxicity to dopaminergic neurons in an age-dependent manner and induced the formation of Lewy body-like α-syn aggregates in the substantia nigra. These results provide new insights into how α-syn-induced toxicity is related to its aggregation

    A cluster randomised control trial to evaluate the effectiveness and cost-effectiveness of the Italian medicines use review (I-MUR) for asthma patients

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    Background The economic burden of asthma, which relates to the degree of control, is €5 billion annually in Italy. Pharmacists could help improve asthma control, reducing this burden. This study aimed to evaluate the effectiveness and cost-effectiveness of Medicines Use Reviews provided by community pharmacists in asthma. Methods This cluster randomised, multi-centre, controlled trial in adult patients with asthma was conducted in 15 of the 20 regions of Italy between September 2014 and July 2015. After stratification by region, community pharmacists were randomly allocated to group A (trained in and delivered the intervention at baseline) or B (training and delivery 3 months later), using computerised random number generation in blocks of 10. Each recruited up to five patients, with both groups followed for 9 months. The intervention consisted of a systematic, structured face-to-face consultation with a pharmacist, covering asthma symptoms, medicines used, attitude towards medicines and adherence, recording pharmacist-identified pharmaceutical care issues (PCIs). The primary outcome was asthma control, assessed using the Asthma-Control-Test (ACT) score (ACT ≥ 20 represents good control). Secondary outcomes were: number of active ingredients, adherence, cost-effectiveness compared with usual care. Although blinding was not possible for either pharmacists or patients, assessment of outcomes was conducted by researchers blind to group allocation. Results Numbers of pharmacists and patients enrolled were 283 (A = 136; B = 147) and 1263 (A = 600; B = 663), numbers completing were 201 (A = 97; B = 104) and 816 (A = 400; B = 416), respectively. Patients were similar in age and gender and 56.13% (458/816) had poor/partial asthma control. Pharmacists identified 1256 PCIs (mean 1.54/patient), mostly need for education, monitoring and potentially ineffective therapy. Median ACT score at baseline differed between groups (A = 19, B = 18; p < 0.01). Odds ratio for improved asthma control was 1.76 (95% CI 1.33–2.33) and number needed to treat 10 (95% CI 6–28). Number of active ingredients reduced by 7.9% post-intervention (p < 0.01). Adherence improved by 35.4% 3 months post-intervention and 40.0% at 6 months (p < 0.01). The probability of the intervention being more cost-effective than usual care was 100% at 9 months. Conclusions This community pharmacist-based intervention demonstrated both effectiveness and cost-effectiveness. It has since been implemented as the first community pharmacy cognitive service in Italy

    Effect of Spermidine on Misfolding and Interactions of Alpha-Synuclein

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    Alpha-synuclein (α-Syn) is a 140 aa presynaptic protein which belongs to a group of natively unfolded proteins that are unstructured in aqueous solutions. The aggregation rate of α-Syn is accelerated in the presence of physiological levels of cellular polyamines. Here we applied single molecule AFM force spectroscopy to characterize the effect of spermidine on the very first stages of α-Syn aggregation – misfolding and assembly into dimers. Two α-Syn variants, the wild-type (WT) protein and A30P, were studied. The two protein molecules were covalently immobilized at the C-terminus, one at the AFM tip and the other on the substrate, and intermolecular interactions between the two molecules were measured by multiple approach-retraction cycles. At conditions close to physiological ones at which α-Syn misfolding is a rare event, the addition of spermidine leads to a dramatic increase in the propensity of the WT and mutant proteins to misfold. Importantly, misfolding is characterized by a set of conformations, and A30P changes the misfolding pattern as well as the strength of the intermolecular interactions. Together with the fact that spermidine facilitates late stages of α-Syn aggregation, our data demonstrate that spermidine promotes the very early stages of protein aggregation including α-Syn misfolding and dimerization. This finding suggests that increased levels of spermidine and potentially other polyamines can initiate the disease-related process of α-Syn
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