Distinct ubiquitin binding modes exhibited by SH3 domains: Molecular determinants and functional implications

SH3 domains constitute a new type of ubiquitin-binding domains. We previously showed that the third SH3 domain (SH3-C) of CD2AP binds ubiquitin in an alternative orientation. We have determined the structure of the complex between first CD2AP SH3 domain and ubiquitin and performed a structural and mutational analysis to decipher the determinants of the SH3-C binding mode to ubiquitin. We found that the Phe-to-Tyr mutation in CD2AP and in the homologous CIN85 SH3-C domain does not abrogate ubiquitin binding, in contrast to previous hypothesis and our findings for the first two CD2AP SH3 domains. The similar alternative binding mode of the SH3-C domains of these related adaptor proteins is characterised by a higher affinity to C-terminal extended ubiquitin molecules. We conclude that CD2AP/CIN85 SH3-C domain interaction with ubiquitin constitutes a new ubiquitin-binding mode involved in a different cellular function and thus changes the previously established mechanism of EGF-dependent CD2AP/CIN85 mono-ubiquitination. © 2013 Ortega Roldan et al

The high-resolution NMR structure of the R21A Spc-SH3:P41 complex: Understanding the determinants of binding affinity by comparison with Abl-SH3

BACKGROUND: SH3 domains are small protein modules of 60–85 amino acids that bind to short proline-rich sequences with moderate-to-low affinity and specificity. Interactions with SH3 domains play a crucial role in regulation of many cellular processes (some are related to cancer and AIDS) and have thus been interesting targets in drug design. The decapeptide APSYSPPPPP (p41) binds with relatively high affinity to the SH3 domain of the Abl tyrosine kinase (Abl-SH3), while it has a 100 times lower affinity for the α-spectrin SH3 domain (Spc-SH3). RESULTS: Here we present the high-resolution structure of the complex between the R21A mutant of Spc-SH3 and p41 derived from NMR data. Thermodynamic parameters of binding of p41 to both WT and R21A Spc-SH3 were measured by a combination of isothermal titration and differential scanning calorimetry. Mutation of arginine 21 to alanine in Spc-SH3 increases 3- to 4-fold the binding affinity for p41 due to elimination at the binding-site interface of the steric clash produced by the longer arginine side chain. Amide hydrogen-deuterium experiments on the free and p41-bound R21A Spc-SH3 domain indicate that binding elicits a strong reduction in the conformational flexibility of the domain. Despite the great differences in the thermodynamic magnitudes of binding, the structure of the R21A Spc-SH3:P41 complex is remarkably similar to that of the Abl-SH3:P41 complex, with only few differences in protein-ligand contacts at the specificity pocket. Using empirical methods for the prediction of binding energetics based on solvent-accessible surface area calculations, the differences in experimental energetics of binding between the two complexes could not be properly explained only on the basis of the structural differences observed between the complexes. We suggest that the experimental differences in binding energetics can be at least partially ascribed to the absence in the R21A Spc-SH3:P41 complex of several buried water molecules, which have been proposed previously to contribute largely to the highly negative enthalpy and entropy of binding in the Abl-SH3:P41 complex. CONCLUSION: Based on a deep structural and thermodynamic analysis of a low and high affinity complex of two different SH3 domains with the same ligand p41, we underline the importance of taking into account in any effective strategy of rational design of ligands, factors different from the direct protein-ligand interactions, such as the mediation of interactions by water molecules or the existence of cooperative conformational effects induced by binding

Stability study over time of clinical solutions of ziv-aflibercept prepared in infusion bags using a proper combination of physicochemical and functional strategies

The study was entirely funded by Project FIS: PI-17/00547(Instituto Carlos III, Ministerio de Economia y Competitividad, Spain), which means that it was also partially supported by European Regional Development Funds (ERDF).A range of biopharmaceutical products are used to target Vascular Endothelial Growth Factor (VEGF), including Eylea (R) (aflibercept, AFL) and Zaltrap (R) (ziv-aflibercept, ziv-AFL). The first is indicated for ophthalmological diseases such as neovascular (wet) age-related macular degeneration, while the second is used in the treatment of metastatic colorectal cancer. The stability of AFL in prefilled syringes has been widely studied; however, no research has yet been done on the stability of ziv-AFL in polyolefin infusion bags. Therefore, the purpose of the present research is to evaluate the stability of ziv-AFL (Zaltrap (R)) clinical solutions prepared under aseptic conditions in polyolefin infusion bags at two different concentrations, i.e. 4.0 and 0.6 mg/mL, and stored refrigerated in darkness at 2-8 degrees C for 14 days. With that aim, the ziv-AFL clinical solutions were assessed by analysing changes in its physicochemical and functional properties. The distribution of the particulates was studied over a range of 0.001-10 mu m by Dynamic Light Scattering (DLS); oligomers were analysed by Size-Exclusion High-Performance Chromatography with Diode Array Detection (SE/HLPC-DAD); the secondary structure of the protein was studied by far UV Circular Dichroism (CD) and the tertiary structure by Intrinsic Tryptophan Fluorescence (IT-F) and Intrinsic Protein Fluorescence (IP-F); charge variants were assessed by Strong Cation Exchange Ultra High-Performance Chromatography with UV detection (SCX/UHPLC-UV); functionality was evaluated by ELISA by measuring the biological activity as manifested in the extension of the immunological reaction of the ziv-AFL with its antigen (VEGF). Neither aggregation nor oligomerization were detected by the techniques mentioned above. Secondary and tertiary structures remained unchanged over the 14-day period, as did charge variants. The functionality observed initially was maintained along time. Therefore, it could be proposed that the ziv-AFL clinical solutions studied showed great physicochemical and functional stability over a period of two weeks, regardless of the concentration, i.e. 4 or 0.6 mg/mL.Project FIS (Instituto Carlos III, Ministerio de Economia y Competitividad, Spain) PI-17/00547European Commissio

Rabbit seminal plasma proteome: The importance of the genetic origin

[EN] The present study was conducted to characterise rabbit seminal plasma proteins (SP proteins) focusing on the influence of the genetic origin and seasonality. In addition, ß-NGF protein quantity in SP was determined. Semen samples were recovered from January to December 2014 using 6 males belonging to genotype A and six from genotype R. For each genotype, one pooled sample at the beginning, middle and end of each season was selected to develop the experiment. A total of 24 pools (3 for each season and genetic line) were analysed. SP proteins of the two experimental groups were recovered and subjected to in-solution digestion nano LC¿MS/MS and bioinformatics analysis. The resulting library included 402 identified proteins validated with ¿95% Confidence (unused Score¿1.3). These data are available via ProteomeXchange with identifier PXD006308. Only 6 proteins were specifically implicated in reproductive processes according to Gene Ontology annotation. Twenty-three proteins were differentially expressed between genotypes, 11 over-expressed in genotype A and 12 in genotype R. Regarding the effect of season on rabbit SP proteome, results showed that there is no clear pattern of protein variation throughout the year. Similar ß-NGF relative quantity was observed between seasons and genotypes. In conclusion, this study generates the largest library of SP proteins reported to date in rabbits and provides evidence that genotype is related to a specific abundance of SP proteins.This research was supported in part by the RTA2013-00058-00-00 from INIA, the European Social Fund and the European FEDER Funds. L. Casares-Crespo is supported by a scholarship from Instituto Valenciano de Investigaciones Agrarias (IVIA) and the European Social Fund. P. Fernandez-Serrano is supported by Spanish funds from IVIA and Ministerio de Empleo y Seguridad Social (Youth Guarantee Program). The authors are grateful to M. Luz Valero for her excellent technical assistance.Casares-Crespo, L.; Fernández-Serrano, P.; Vicente Antón, JS.; Marco-Jiménez, F.; Viudes De Castro, MP. (2018). Rabbit seminal plasma proteome: The importance of the genetic origin. Animal Reproduction Science. 189:30-42. https://doi.org/10.1016/j.anireprosci.2017.12.004S304218

Comprehensive biophysical and functional study of ziv-aflibercept: characterization and forced degradation

This study was entirely funded by Project FIS: PI-17/00547 (Instituto Carlos III, Ministerio de Economia y Competitividad, Spain), which means that it was also partially supported by European Regional Development Funds (ERDF).Aflibercept (AFL) is an Fc fusion protein used in the treatment of colorectal cancers and different ophthalmological diseases. There are two medicines in which AFL is the active substance: Zaltrap and Eylea, referred as ziv-AFL and AFL respectively. No proper accelerated degradation studies were published on either AFL or ziv-AFL. These studies are essential during research, development and manufacturing stages. Here, we characterized ziv-AFL and submitted it to different stress conditions: light, 60 °C, freeze-thaw cycles, changes in pH, high hypertonic solution and strong denaturing conditions. We used an array of techniques to detect aggregation (SE-HPLC/DAD and DLS), changes in secondary structure (Far-UV circular dichroism), changes in conformation or tertiary structure (Intrinsic tryptophan fluorescence) and alterations in functionality (ELISA). Results indicate that aggregation is common degradation pathway. Two different types of aggregates were detected: dimers and high molecular weight aggregates attributed to β-amyloid-like structures. Secondary structure was maintained in most of the stress tests, while conformation was altered by almost all the tests except for the freeze-thaw cycles. Functionality, evaluated by its immunochemical reaction with VEGF, was found to be stable but with decrease when exposed to light and with likely partial inactivation of the drug when pH was altered.European Union (EU) FIS: PI-17/0054

Tuning properties of biomimetic magnetic nanoparticles by combining magnetosome associated proteins

The role of magnetosome associated proteins on the in vitro synthesis of magnetite nanoparticles has gained interest, both to obtain a better understanding of the magnetosome biomineralization process and to be able to produce novel magnetosome-like biomimetic nanoparticles. Up to now, only one recombinant protein has been used at the time to in vitro form biomimetic magnetite precipitates, being that a scenario far enough from what probably occurs in the magnetosome. In the present study, both Mms6 and MamC from Magnetococcus marinus MC-1 have been used to in vitro form biomimetic magnetites. Our results show that MamC and Mms6 have different, but complementary, effects on in vitro magnetite nucleation and growth. MamC seems to control the kinetics of magnetite nucleation while Mms6 seems to preferably control the kinetics for crystal growth. Our results from the present study also indicate that it is possible to combine both proteins to tune the properties of the resulting biomimetic magnetites. In particular, by changing the relative ratio of these proteins, better faceted and/or larger magnetite crystals with, consequently, different magnetic moment per particle could be obtained. This study provides with tools to obtain new biomimetic nanoparticles with a potential utility for biotechnological applicationsWe acknowledge projects CGL2013-46612 and CGL2016-76723 from the Ministerio de Economía y Competitividad from SPAIN and Fondo Europeo de Desarrollo Regional (FEDER) for financial support and Unidad Científica de Excelencia UCE-PP2016-05 of the University of Granada. Thanks go to CIC personnel of the University of Granada for technical assistance in the CD, TEM, SQUID and Unidad de Radioquímica e Inmunoanalisis (LAR), to the Proteomics Unit personnel of the Institute of Parasitology and Biomedicine “López- Neyra” (IPBLN) for technical assistance in the PMF and PFF by MALDI-TOF/TOF, and to the University of Málaga for technical assintance in HRTEM measurements

Insemination extender supplementation with bestatin and EDTA has no effect on rabbit reproductive performance

[EN] The addition of aminopeptidase inhibitors (AMIs) to rabbit semen extenders could be a solution to decrease the hormone degradation (GnRH) by the aminopeptidases existing in the seminal plasma. Therefore, the quantity of GnRH needed to induce ovulation in doe would be comparable with the amount administered intramuscularly (i.m.). This study was conducted to evaluate the effects of two AMIs (bestatin and EDTA) on rabbit semen quality parameters, beta nerve growth factor ((beta-NGF) degradation and reproductive performance after artificial insemination. Results showed that seminal quality was not affected by the incubation with AMIs; the values of motility, acrosome integrity and sperm viability were not significantly different between the AMIs and the control groups (positive i.m. and negative intravaginally without AMIs). In addition, the aminopeptidase activity of seminal plasma was inhibited in a 55.5% by the AMIs as well as beta-NGF degradation. On the other hand, regarding the effect of AMIs on reproductive performance, our results showed that the presence of bestatin and EDTA did neither affect fertility (85.3 vs. 88.6%), nor the prolificacy rate (10.12 vs. 10.51 kits per delivery), comparing AMIs group to positive control group, respectively. We conclude that the addition of specific AMIs in the rabbit semen extender has no effect on reproductive performance. Therefore, due to the fact that AMIs inhibit part of the aminopeptidase activity that degrades the GnRH analogue and beta-NGF, they could be used to develop new extenders with less hormone concentration. (C) 2017 Elsevier Inc. All rights reserved.This research was supported in part by the RTA2013-00058-00-00 from INIA, the European Social Fund and the European FEDER Funds. L. Casares-Crespo is supported by a scholarship from Instituto Valenciano de Investigaciones Agrarias (IVIA) and the European Social Fund. P. Fernandez-Serrano is supported by funds from Instituto Valenciano de Investigaciones Agrarias (IVIA) and Ministerio de Empleo y Seguridad Social (Programa de Garantia Juvenil).Casares-Crespo, L.; Fernández-Serrano, P.; Vicente Antón, JS.; Moce Cervera, ET.; Castellini, C.; Stabile, A.; Viudes De Castro, MP. (2018). Insemination extender supplementation with bestatin and EDTA has no effect on rabbit reproductive performance. Theriogenology. 105:61-65. https://doi.org/10.1016/j.theriogenology.2017.09.009S616510

Jejunal microvilli atrophy and reduced nutrient transport in rats with advanced liver cirrhosis: improvement by Insulin-like Growth Factor I

Es reproducción del documenteo publicado en http://dx.doi.org/10.1186/1471-230X-4-12Background: Previous results have shown that in rats with non-ascitic cirrhosis there is an altered transport of sugars and amino acids associated with elongated microvilli. These alterations returned to normal with the administration of Insulin-Like Growth Factor-I (IGF-I). The aims of this study were to explore the evolution of these alterations and analyse the effect of IGF-I in rats with advanced cirrhosis and ascites. Thus, jejunal structure and nutrient transport (D-galactose, L-leucine, L-proline, L-glutamic acid and L-cystine) were studied in rats with ascitic cirrhosis. Methods: Advanced cirrhosis was induced by CCl4 inhalation and Phenobarbital administration for 30 weeks. Cirrhotic animals were divided into two groups which received IGF-I or saline during two weeks. Control group was studied in parallel. Jejunal microvilli were studied by electron microscopy. Nutrient transport was assessed in brush border membrane vesicles using C-14 or S-35-labelled subtracts in the three experimental groups. Results: Intestinal active Na+-dependent transport was significantly reduced in untreated cirrhotic rats. Kinetic studies showed a decreased V-max and a reduced affinity for sugar and four amino acids transporters ( expressed as an increased K-t) in the brush border membrane vesicles from untreated cirrhotic rats as compared with controls. Both parameters were normalised in the IGF-I-treated cirrhotic group. Electron microscopy showed elongation and fusion of microvilli with degenerative membrane lesions and/or notable atrophy. Conclusions: The initial microvilli elongation reported in non ascitic cirrhosis develops into atrophy in rats with advanced cirrhosis and nutrient transports (monosaccharides and amino acids) are progressively reduced. Both morphological and functional alterations improved significantly with low doses of IGF-I

Generation of a novel model of bioengineered human oral mucosa with increased vascularization potential

Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+I) of the Spanish Ministry of Science and Innovation (Instituto de Salud Carlos III), Grant/Award Number: FIS PI18/331, FIS PI21/00980, FIS PI18/332 and ICI19/00024; Consejeria de Salud y Familias, Junta de Andalucia, Spain, Grant/Award Number: PI-0442--2019; FEDER funds, European UnionObjective: The aim of this study was to generate novel models of bioartificial human oral mucosa with increased vascularization potential for future use as an advanced therapies medicinal product, by using different vascular and mesenchymal stem cell sources. Background: Oral mucosa substitutes could contribute to the clinical treatment of complex diseases affecting the oral cavity. Although several models of artificial oral mucosa have been described, biointegration is a major issue that could be favored by the generation of novel substitutes with increased vascularization potential once grafted in vivo. Methods: Three types of mesenchymal stem cells (MSCs) were obtained from adipose tissue, bone marrow, and dental pulp, and their in vitro potential was evaluated by inducing differentiation to the endothelial lineage using conditioning media. Then, 3D models of human artificial oral mucosa were generated using biocompatible fibrin-agarose biomaterials combined with human oral mucosa fibroblasts and each type of MSC before and after induction to the endothelial lineage, using human umbilical vein endothelial cells (HUVEC) as controls. The vascularization potential of each oral mucosa substitute was assessed in vitro and in vivo in nude mice. Results: In vitro induction of MSCs kept in culture was able to increase the expression of VEGF, CD31, and vWF endothelial markers, especially in bone marrow and dental pulp-MSCs, and numerous proteins with a role in vasculogenesis become overexpressed. Then, in vivo grafting resulted in a significant increase in blood vessels formation at the interface area between the graft and the host tissues, with significantly positive expression of VEGF, CD31, vWF, and CD34 as compared to negative controls, especially when pre-differentiated MSCs derived from bone marrow and dental pulp were used. In addition, a significantly higher number of cells committed to the endothelial lineage expressing the same endothelial markers were found within the bioartificial tissue. Conclusion: Our results suggest that the use of pre-differentiated MSCs could contribute to a rapid generation of a vascular network that may favor in vivo biointegration of bioengineered human oral mucosa substitutes.Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+I) of the Spanish Ministry of Science and Innovation (Instituto de Salud Carlos III) FIS PI18/331 FIS PI21/00980 FIS PI18/332 ICI19/00024Junta de Andalucia PI-0442-2019European Commissio

Emergency Crisis Resource Management course: a tool for transforming attitudes within emergency service teams

[ES] OBJETIVO. Conocer la percepción sobre la influencia del factor humano en urgencias que adquieren los alumnos trasla realización de un curso E-CRM (Emergency Crisis Resource Management) de la Sociedad Española de Urgencias y Emergencias (SEMES) basado en simula ción clínica. MATERIAL Y MÉTODO. Se analizaron las respuestas a un cuestionario ad hoc administrado a los 3 meses de las ediciones de los cursos E-CRM SEMES realizados entre 2017-19. El cuestionario valoraba la autopercepción sobre la influencia que ha tenido el curso en su desarrollo personal y profesional. RESULTADOS. Se recogieron las encuestas de 147 participantes (73,5% médicos, 20,4% enfermeras, 5,4% TES (Técnico en Emergencias Sanitarias) y 1,4% otras profesiones. El 65% de los profesionales tenía una antigüedad de más de 10 años. Existieron diferencias significativas entre las diferentes profesiones y servicios en los 5 ejes E-CRM (petición de ayuda, claridad de papeles, comunicación eficaz, uso de recursos y evaluación global). Se destacó el uso de ayudas cognitivas, la escucha activa y la planificación previa al inicio del turno. CONCLUSIONES. Tras la realización de un curso E-CRM basado en simulación, los participantes son conscientes de cómo el factor humano influye en el desempeño de su trabajo en los servicios de urgencias y emergencias, lo que pueder llevar a introducir cambios en su quehacer profesional y personal.[EN] OBJECTIVE. To know the perception of the influence of the human factor in emergencies, acquired by students after completing an E-CRM (Emergency Crisis Resource Management) course of the Spanish Society of Emergency Medicine and Emergency Medicine (SEMES) based on clinical simulation. E-CRM (Emergency Crisis Resource Management) course of the Spanish Society of Emergency Medicine (SEMES) based on clinical simulation. METHODS. We analyzed responses to an ad hoc survey sent to participants 3 months after they completed the E-CRM course between 2017 and 2019. We analyzed their views of the influence the course had on their personal and professional development. RESULTS. Responses were received from 147 course participants (73.5%, physicians; 20.4%, nurses; 5.4%, emergency medical technicians; and 1.4%, other). Sixty-five percent had more than 10 years of experience. The different groups of participants gave significantly different responses for the 5 question categories: seeking help, role clarification, effective communication, resource use, and overall evaluation. Respondents emphasized their use of cognitive aids, active listening, and team planning prior to starting a shift. CONCLUSIONS. After the E-CRM clinical simulation course, respondents reported being more aware of how human factors influence their personal and professional approaches to carrying out their emergency service work.S