Structural Analysis of Prolyl Oligopeptidases Using Molecular Docking and Dynamics: Insights into Conformational Changes and Ligand Binding

Prolyl oligopeptidase (POP) is considered as an important pharmaceutical target for the treatment of numerous diseases. Despite enormous studies on various aspects of POPs structure and function still some of the questions are intriguing like conformational dynamics of the protein and interplay between ligand entry/egress. Here, we have used molecular modeling and docking based approaches to unravel questions like differences in ligand binding affinities in three POP species (porcine, human and A. thaliana). Despite high sequence and structural similarity, they possess different affinities for the ligands. Interestingly, human POP was found to be more specific, selective and incapable of binding to a few planar ligands which showed extrapolation of porcine POP in human context is more complicated. Possible routes for substrate entry and product egress were also investigated by detailed analyses of molecular dynamics (MD) simulations for the three proteins. Trajectory analysis of bound and unbound forms of three species showed differences in conformational dynamics, especially variations in β-propeller pore size, which was found to be hidden by five lysine residues present on blades one and seven. During simulation, β-propeller pore size was increased by ∼2 Å in porcine ligand-bound form which might act as a passage for smaller product movement as free energy barrier was reduced, while there were no significant changes in human and A. thaliana POPs. We also suggest that these differences in pore size could lead to fundamental differences in mode of product egress among three species. This analysis also showed some functionally important residues which can be used further for in vitro mutagenesis and inhibitor design. This study can help us in better understanding of the etiology of POPs in several neurodegenerative diseases

Kaolin from Acoculco (Puebla, Mexico) as a raw material: mineralogical and thermal characterization

The present study determined the mineralogy and thermal properties of kaolin from Acoculco (Puebla), at the eastern Trans-Mexican Volcanic Belt and compared it with the nearby deposits of Agua Blanca (Hidalgo) and Huayacocotla (Veracruz). The mineralogy of the kaolins was determined by X-ray diffraction, infrared spectroscopy and scanning electron microscopy. Thermal behaviour was studied by differential thermal analysis, dilatometry and hot-stage microscopy. The Acoculco deposit is composed mainly of kaolinite and SiO2 minerals. In the case of Agua Blanca and Huayacocotla, alunite is abundant in places and minor anatase is also present locally. The Acoculco kaolins are Fe-poor and relatively rich in some potentially toxic elements (Zr, Sb, Pb). They undergo a relatively small amount of shrinkage (∼3-4 vol.%), during firing at 20-1300°C and cooling down to 20°C, except when >10 wt.% alunite is present. These kaolins are a suitable raw material for the ceramics industry. Other applications (pharmaceuticals, cosmetics) would require an enrichment process to eliminate impurities such as Fe oxides

A mechanically active heterotypic E-cadherin/N-cadherin adhesion enables fibroblasts to drive cancer cell invasion

Cancer-associated fibroblasts (CAFs) promote tumour invasion and metastasis. We show that CAFs exert a physical force on cancer cells that enables their collective invasion. Force transmission is mediated by a heterophilic adhesion involving N-cadherin at the CAF membrane and E-cadherin at the cancer cell membrane. This adhesion is mechanically active; when subjected to force it triggers β-catenin recruitment and adhesion reinforcement dependent on α-catenin/vinculin interaction. Impairment of E-cadherin/N-cadherin adhesion abrogates the ability of CAFs to guide collective cell migration and blocks cancer cell invasion. N-cadherin also mediates repolarization of the CAFs away from the cancer cells. In parallel, nectins and afadin are recruited to the cancer cell/CAF interface and CAF repolarization is afadin dependent. Heterotypic junctions between CAFs and cancer cells are observed in patient-derived material. Together, our findings show that a mechanically active heterophilic adhesion between CAFs and cancer cells enables cooperative tumour invasion

Development of Innovative Antiatherosclerotic Peptides through the Combination of Molecular Modeling and a Dual (Biochemical‐Cellular) Screening System

Cardiovascular disease (CVD) is a leading cause of death worldwide. Approximately 60% of patients treated with low‐density lipoprotein (LDL)‐lowering drug treatments, with on‐target plasma cholesterol levels, are still suffering clinical acute ischemic events. Mechanisms, such as LDL aggregation, underlie extracellular and intracellular cholesterol accumulation in the vasculature. A peptide sequence (P3) of the low‐density lipoprotein receptor‐related protein 1 (LRP1) efficiently protects LDL from sphingomyelinase (SMase‐) and phospholipase A2 (PLA2)‐induced LDL aggregation. The aim is to design families of peptide derivatives from P3 with enhanced potency and proteolytic stability. New peptides are designed through in silico conformational sampling and ApoB‐100 molecular docking, and are tested in dual (biochemical‐cellular) screening assays. A total of 46 new peptides including linear, fragment, cyclic, and alanine scanning derivatives are generated through two consecutive optimization rounds. Structurally and functionally optimized peptides contain hotspot residues that are replaced by alanine. This strategy confers an increased capacity to form prone alpha‐helix conformations crucial for the electrostatic interaction with ApoB‐100. These new compounds are highly efficient at inhibiting LDL aggregation and human coronary vascular smooth muscle cell‐cholesteryl ester loading and should be studied in preclinical models of atherosclerosis.Cardiovascular disease (CVD) is a leading cause of death worldwide. Approximately 60% of patients treated with low‐density lipoprotein (LDL)‐lowering drug treatments, with on‐target plasma cholesterol levels, are still suffering clinical acute ischemic events. Mechanisms, such as LDL aggregation, underlie extracellular and intracellular cholesterol accumulation in the vasculature. A peptide sequence (P3) of the low‐density lipoprotein receptor‐related protein 1 (LRP1) efficiently protects LDL from sphingomyelinase (SMase‐) and phospholipase A2 (PLA2)‐induced LDL aggregation. The aim is to design families of peptide derivatives from P3 with enhanced potency and proteolytic stability. New peptides are designed through in silico conformational sampling and ApoB‐100 molecular docking, and are tested in dual (biochemical‐cellular) screening assays. A total of 46 new peptides including linear, fragment, cyclic, and alanine scanning derivatives are generated through two consecutive optimization rounds. Structurally and functionally optimized peptides contain hotspot residues that are replaced by alanine. This strategy confers an increased capacity to form prone alpha‐helix conformations crucial for the electrostatic interaction with ApoB‐100. These new compounds are highly efficient at inhibiting LDL aggregation and human coronary vascular smooth muscle cell‐cholesteryl ester loading and should be studied in preclinical models of atherosclerosis.A.B.-A. and C.P. contributed equally to this work. The authors thank Dr. Ignasi Gich, Professor of Clinical Pharmacology and Therapeutics and Researcher of Sant Pau Biomedical Research Institute (IIB-SantPau) and CIBER Epidemiología y Salud Pública (CIBERESP), for this help in statistical analysis and graph representations. The Ministry of Science and Innovation of Spain, in the framework of the State Plan of Scientific and Technical Innovation Investigation 2013–2016, awarded funding to the project “DEVELOPMENT OF AN INNOVATIVE THERAPY FOR THE TREATMENT OF THE ATHEROSCLEROSIS THROUGH INHIBITION OF CHOLESTEROL VASCULAR ACCUMULATION” led by IPROTEOS SL with File No. RTC-2016-5078-1. Support was also received from the Fundació MARATÓ TV3 Project 201521-10 (to VLl-C), and FIS PI18/01584 (to VLl-C) from the Instituto de Salud Carlos III (ISCIII) and cofinanced with ERDFs. Support was also received from Ministerio de Economía y Competitividad to DdG-C (IJCI-2016-29393). CIBER Enfermedades Cardiovasculares (CIBERCV; CB16/1100403 (DdG-C, VLl-C) are projects run by the Instituto de Salud Carlos III (ISCIII). The authors also acknowledge the support from “Secretaria d’Universitats i Recerca del Departament d’Economia I Coneixement de la Generalitat de Catalunya” (2017SGR946 to VLl-C).Peer reviewe

Assessment of Antibody Response Elicited by a 7-valent Pneumococcal Conjugate Vaccine in Pediatric Human Immunodeficiency Virus Infection

We investigated antibody responses against pneumococci of serotypes 6B, 14, and 23F in 56 children and adolescents with perinatal human immunodeficiency virus (HIV) infection who were vaccinated with 7-valent pneumococcal conjugate vaccine. Overall immune responses differed greatly between serotypes. Correlation coefficients between immunoglobulin G (IgG) measured by enzyme-linked immunosorbent assay (ELISA) and functional antibodies measured by a flow cytometry opsonophagocytosis assay (OPA) varied with serotype and time points studied. After 3 months of administering a second PCV7 dose we got the highest correlation (with significant r values of 0.754, 0.414, and 0.593 for serotypes 6B, 14, and 23F, respectively) but no significant increase in IgG concentration and OPA titers compared to the first dose. We defined a responder to a serotype included in the vaccine with two criteria: frequency of at least twofold OPA and ELISA increases for each serotype and frequency of conversion from negative to positive OPA levels. Responders varied from 43.9% to 46.3%, 28.5% to 50.0%, and 38.0% to 50.0% for serotypes 6B, 14, and 23F, respectively, depending on the response criterion. The present research highlights the importance of demonstrating vaccine immunogenicity with suitable immunological endpoints in immunocompromised patients and also the need to define how much antibody is required for protection from different serotypes, since immunogenicity differed significantly between serotypes

Effectiveness of percutaneous electrical nerve stimulation for musculoskeletal pain: A systematic review and meta-analysis

Background and Objective: To evaluate the effects of percutaneous electrical stimulation (PENS) alone or as an adjunct with other interventions on pain and related disability in musculoskeletal pain conditions. Databases and Data Treatment: Search of MEDLINE, EMBASE, AMED, CINAHL, EBSCO, PubMed, PEDro, Cochrane Library, SCOPUS and Web of Science databases. Randomized controlled trials where at least one group received any form of PENS for musculoskeletal condition. Studies had to include humans and collect outcomes on pain and related disability in musculoskeletal pain. Risk of bias was assessed by the Cochrane Guidelines, the quality of evidence by using the GRADE approach. Standardized mean differences (SMD) were calculated. Results: Sixteen studies were included and included heterogeneous musculoskeletal conditions with short- or midterm follow-ups. PENS alone had a large effect (SMD −1.22, 95% CI −1.66 to −0.79) on pain and a small effect (SMD −0.33, 95% CI −0.61 to −0.06) on related disability at short-term as compared with sham. A moderate effect of PENS alone (SMD −0.71, 95% CI −1.23 to −0.19) on pain when compared with other interventions was observed. The inclusion of PENS with other interventions had a moderate effect for decreasing pain at short- (SMD −0.70, 95% CI −1.02 to −0.37) and midterm (SMD −0.68, 95% CI −1.10 to −0.27). No effect at midterm (SMD −0.21, 95% CI −0.52 to 0.10) on related disability was seen. The risk of bias was generally low; but the heterogenicity of the results downgraded the level of evidence. Conclusion: There is low level of evidence suggesting the effects of PENS alone or in combination for pain, but not related disability, in musculoskeletal pain. Level of Evidence: Therapy, level 1a. Registration number: CRD42019131331. Significance: This meta-analysis investigating the effectiveness of PENS for the management of pain and related disability in musculoskeletal pain conditions found that PENS could decrease level of pain intensity but not relateddisability in musculoskeletal pain disorders

Kaolin from Acoculco (Puebla, Mexico) as a raw material: mineralogical and thermal characterization

The present study determined the mineralogy and thermal properties of kaolin from Acoculco (Puebla), at the eastern Trans-Mexican Volcanic Belt and compared it with the nearby deposits of Agua Blanca (Hidalgo) and Huayacocotla (Veracruz). The mineralogy of the kaolins was determined by X-ray diffraction, infrared spectroscopy and scanning electron microscopy. Thermal behaviour was studied by differential thermal analysis, dilatometry and hot-stage microscopy. The Acoculco deposit is composed mainly of kaolinite and SiO2 minerals. In the case of Agua Blanca and Huayacocotla, alunite is abundant in places and minor anatase is also present locally. The Acoculco kaolins are Fe-poor and relatively rich in some potentially toxic elements (Zr, Sb, Pb). They undergo a relatively small amount of shrinkage (∼3-4 vol.%), during firing at 20-1300°C and cooling down to 20°C, except when >10 wt.% alunite is present. These kaolins are a suitable raw material for the ceramics industry. Other applications (pharmaceuticals, cosmetics) would require an enrichment process to eliminate impurities such as Fe oxides