LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 12

Search options

  1. Article ; Online: Structure-Function Insights into the Fungal

    Jiménez-Ortega, Elena / Kidibule, Peter Elias / Fernández-Lobato, María / Sanz-Aparicio, Julia

    International journal of molecular sciences

    2022  Volume 23, Issue 14

    Abstract: Chitin is the most widespread amino renewable carbohydrate polymer in nature and the second most abundant polysaccharide. Therefore, chitin and chitinolytic enzymes are becoming more importance for biotechnological applications in food, health and ... ...

    Abstract Chitin is the most widespread amino renewable carbohydrate polymer in nature and the second most abundant polysaccharide. Therefore, chitin and chitinolytic enzymes are becoming more importance for biotechnological applications in food, health and agricultural fields, the design of effective enzymes being a paramount issue. We report the crystal structure of the plant-type
    MeSH term(s) Catalysis ; Chitin/metabolism ; Chitinases/metabolism ; Molecular Weight ; Substrate Specificity
    Chemical Substances Chitin (1398-61-4) ; Chitinases (EC 3.2.1.14)
    Language English
    Publishing date 2022-07-09
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms23147599
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article: Structural inspection and protein motions modelling of a fungal glycoside hydrolase family 18 chitinase by crystallography depicts a dynamic enzymatic mechanism

    Jiménez-Ortega, Elena / Kidibule, Peter Elias / Fernández-Lobato, María / Sanz-Aparicio, Julia

    Computational and Structural Biotechnology Journal. 2021, v. 19

    2021  

    Abstract: Chitinases degrade chitin into low molecular weight chitooligomers, which have a broad range of industrial, agricultural, and medical functions. Understanding the relationship between the diverse characteristics of chitinases and their functions is ... ...

    Abstract Chitinases degrade chitin into low molecular weight chitooligomers, which have a broad range of industrial, agricultural, and medical functions. Understanding the relationship between the diverse characteristics of chitinases and their functions is necessary for the improvement of functional enzymes that meet specific requirements. We report here a full crystallographic analysis of three complexes obtained from the chitinase Chit42 from Trichoderma harzianum, which represent different states along the enzymatic mechanism. The inactive double mutant D169A/E171A was submitted to soaking/crystallization experiments with hexa-N-acetyl-glucosamine (NAG6) or tetra-N-acetyl-glucosamine (NAG4), trapping the enzyme-substrate complex (Chit42-NAG6), the enzyme-products complex (Chit42-NAG4-NAG2) and a someway intermediate state. Structural comparison among the different complexes depicts the determinants defining the different subsites and revealed a previously unobserved dynamic on-off ligand binding process associated with a motion of its insertion domain, which might be accompanying the role or aromatics in processivity. An ensemble refinement performed to extract dynamic details from the diffraction data elucidates the implication of some highly flexible residues in the productive sliding of the substrate and the product release event. These positions were submitted to mutagenesis and the activity of the variants was investigated in the hydrolysis of NAG6, colloidal chitin and two chitosans with different polymerization and acetylation degree. All the changes affected the Chit42 hydrolytic activity therefore confirming the involvement of these positions in catalysis. Furthermore, we found the variants R295S and E316S improving the apparent catalytic efficiency of chitin and NAG6 and, together with E316A, enhancing the specific activity on chitosan. Therefore, our results provide novel insight into the molecular mechanisms underlying the hydrolysis of chitinous material by fungal chitinases, and suggest new targets to address engineering of these biotechnologically important enzymes.
    Keywords Trichoderma harzianum ; acetylation ; aromatic compounds ; biotechnology ; catalytic activity ; chitin ; chitinase ; chitosan ; crystallization ; crystallography ; enzyme substrates ; fungi ; glycosides ; hydrolysis ; ligands ; molecular weight ; mutagenesis ; mutants ; polymerization
    Language English
    Size p. 5466-5478.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 2694435-2
    ISSN 2001-0370
    ISSN 2001-0370
    DOI 10.1016/j.csbj.2021.09.027
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article: Structural inspection and protein motions modelling of a fungal glycoside hydrolase family 18 chitinase by crystallography depicts a dynamic enzymatic mechanism.

    Jiménez-Ortega, Elena / Kidibule, Peter Elias / Fernández-Lobato, María / Sanz-Aparicio, Julia

    Computational and structural biotechnology journal

    2021  Volume 19, Page(s) 5466–5478

    Abstract: Chitinases degrade chitin into low molecular weight chitooligomers, which have a broad range of industrial, agricultural, and medical functions. Understanding the relationship between the diverse characteristics of chitinases and their functions is ... ...

    Abstract Chitinases degrade chitin into low molecular weight chitooligomers, which have a broad range of industrial, agricultural, and medical functions. Understanding the relationship between the diverse characteristics of chitinases and their functions is necessary for the improvement of functional enzymes that meet specific requirements. We report here a full crystallographic analysis of three complexes obtained from the chitinase Chit42 from
    Language English
    Publishing date 2021-10-02
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 2694435-2
    ISSN 2001-0370
    ISSN 2001-0370
    DOI 10.1016/j.csbj.2021.09.027
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article ; Online: Mapping the Landscape of Citizen Science in Africa

    Peter Elias / Adenike Shonowo / Alex de Sherbinin / Carolynne Hultquist / Finn Danielsen / Caren Cooper / Maria Mondardini / Elaine Faustman / Anne Browser / Jean-Bernard Minster Minster / Martie van Deventer / Ioana Popescu

    Citizen Science: Theory and Practice, Vol 8, Iss 1, Pp 33-

    Assessing its Potential Contributions to Sustainable Development Goals 6 and 11 on Access to Clean Water and Sanitation and Sustainable Cities

    2023  Volume 33

    Abstract: Data are vital for and creating knowledge-based solutions to development challenges facing Africa. As a result of gaps in government-funded data collection, and in the interest of promoting community engagement, there is a global movement towards ... ...

    Abstract Data are vital for and creating knowledge-based solutions to development challenges facing Africa. As a result of gaps in government-funded data collection, and in the interest of promoting community engagement, there is a global movement towards consideration of nontraditional sources of data, including citizen science (CS) data. These data are particularly valuable when collected at a high resolution over large spatial extents and long time periods. CS projects and infrastructure are abundant and well documented in the Global North, while needs for participatory projects to fill environmental monitoring gaps may be greater in the Global South. The paper explores the contributions of citizen science projects originating in Africa for two Sustainable Development Goals (SDGs), namely SDG 6, and SDG 11 which are particularly important to the millions of low-income residents of cities across Africa. Using a mixed methods approach that involves online surveys, interviews, expert conference panels, and a desk review, we analyze a total of 53 CS projects focusing on water, sanitation, and urban planning. The paper addresses CS in Africa and CS for SDGs, and documents evidence for participatory and CS data collection in Africa. It also describes the survey methods, including approaches to training of volunteers, sources of funding, data collection methods, and objectives of the tools and projects. Finally, it provides reflections on the challenges of integrating CS into official statistics in Africa, and some lessons learnt from CS projects in Africa. This paper recommends the establishment of an open-source database, creation of a network of CS projects for communication and collaboration, the uptake of citizen-generated data, and continuous funding for such projects in Africa.
    Keywords africa ; citizen science ; participatory data ; data governance ; knowledge-based solutions ; sustainable development goals ; water ; urban ; Science ; Q
    Subject code 306
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher Ubiquity Press
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: Reestruturação, requalificação e dispensas

    Peter Elias

    Dados: Revista de Ciências Sociais, Vol 47, Iss 3, Pp 419-

    um estudo da dinâmica do mercado de trabalho do Reino Unido, 1991-95

    2004  Volume 471

    Abstract: Dans cette étude, on révèle les conséquences à long terme du licenciement, concept incluant l'emploi discontinu, la déqualification et la réduction significative des salaires. Les données fournies par le British Household Panel Survey montrent que les ... ...

    Abstract Dans cette étude, on révèle les conséquences à long terme du licenciement, concept incluant l'emploi discontinu, la déqualification et la réduction significative des salaires. Les données fournies par le British Household Panel Survey montrent que les emplois de l'artisanat ou à basse qualification sont les plus touchés par les vagues de licenciement pendant la période 1991-1995. Les personnes licenciées auraient plus de difficultés à trouver du travail dans les années qui suivent leur licenciement, et la plupart se verraient attribuer des emplois de qualité inférieure en termes de salaire. Des séances de training ont été généralement suivies par les personnes licenciées ayant retrouvé un emploi pendant la période étudiée, mais rien ne prouve que ces séances les protègent des effets négatifs du licenciement.
    Keywords restructuration ; requalification ; licenciement ; marché du travail ; Social sciences (General) ; H1-99
    Language English
    Publishing date 2004-01-01T00:00:00Z
    Publisher Universidade do Estado do Rio de Janeiro
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article: Endo-chitinase Chit33 specificity on different chitinolytic materials allows the production of unexplored chitooligosaccharides with antioxidant activity

    Kidibule, Peter Elias / Santos-Moriano, Paloma / Plou, Francisco Jose / Fernández-Lobato, María

    Biotechnology reports. 2020 Sept., v. 27

    2020  

    Abstract: The biological activity of chitooligosaccharides (COS) has made them targets for industrial and medical sectors. In this work, endo-chitinase Chit33 from Trichoderma harzianum CECT 2413 was expressed in Pichia pastoris GS115 to levels never achieved ... ...

    Abstract The biological activity of chitooligosaccharides (COS) has made them targets for industrial and medical sectors. In this work, endo-chitinase Chit33 from Trichoderma harzianum CECT 2413 was expressed in Pichia pastoris GS115 to levels never achieved before (630 mg/L; 3.3 U/mL), without its biochemical characteristics being substantially affected. Chit33 produced a mixture of fully and partially acetylated COS from different chitin derivatives. HPAEC-PAD Chromatography and mass spectrometry analyses showed that (GlcNAc)₄ and GlcN-(GlcNAc)₂ were mainly produced from colloidal chitin and chitosan, respectively. COS in reaction mixtures were fragmented according to their size and their antioxidant activity analyzed by reducing power and free radical scavenging activity essays. The highest antioxidant activity was achieved with COS in the range of 0.5−2 and 2−10 kDa produced from colloidal chitin and chitosan, respectively, which gives biotechnological potential to both the chitin derivatives of 0.5−10 kDa and the biocatalyst producing them.
    Keywords Komagataella pastoris ; Trichoderma harzianum ; antioxidant activity ; biocatalysts ; biotechnology ; chitin ; chitooligosaccharides ; chitosan ; chromatography ; free radicals ; mass spectrometry
    Language English
    Dates of publication 2020-09
    Publishing place Elsevier B.V.
    Document type Article
    Note NAL-AP-2-clean
    ZDB-ID 2801018-8
    ISSN 2215-017X
    ISSN 2215-017X
    DOI 10.1016/j.btre.2020.e00500
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  7. Article ; Online: Evaluating the Accuracy of Gridded Population Estimates in Slums

    Dana R. Thomson / Andrea E. Gaughan / Forrest R. Stevens / Gregory Yetman / Peter Elias / Robert Chen

    Urban Science, Vol 5, Iss 48, p

    A Case Study in Nigeria and Kenya

    2021  Volume 48

    Abstract: Low- and middle-income country cities face unprecedented urbanization and growth in slums. Gridded population data (e.g., ~100 × 100 m) derived from demographic and spatial data are a promising source of population estimates, but face limitations in ... ...

    Abstract Low- and middle-income country cities face unprecedented urbanization and growth in slums. Gridded population data (e.g., ~100 × 100 m) derived from demographic and spatial data are a promising source of population estimates, but face limitations in slums due to the dynamic nature of this population as well as modelling assumptions. In this study, we compared field-referenced boundaries and population counts from Slum Dwellers International in Lagos (Nigeria), Port Harcourt (Nigeria), and Nairobi (Kenya) with nine gridded population datasets to assess their statistical accuracy in slums. We found that all gridded population estimates vastly underestimated population in slums (RMSE: 4958 to 14,422, Bias: −2853 to −7638), with the most accurate dataset (HRSL) estimating just 39 per cent of slum residents. Using a modelled map of all slums in Lagos to compare gridded population datasets in terms of SDG 11.1.1 (percent of population living in deprived areas), all gridded population datasets estimated this indicator at just 1–3 per cent compared to 56 per cent using UN-Habitat’s approach. We outline steps that might improve that accuracy of each gridded population dataset in deprived urban areas. While gridded population estimates are not yet sufficiently accurate to estimate SDG 11.1.1, we are optimistic that some could be used in the future following updates to their modelling approaches.
    Keywords SDG11 ; urban ; deprivation ; informal settlement ; poverty ; mapping ; Geography. Anthropology. Recreation ; G ; Social Sciences ; H
    Language English
    Publishing date 2021-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  8. Article: Nanoparticles of Lignins and Saccharides from Fishery Wastes as Sustainable UV-Shielding, Antioxidant, and Antimicrobial Biofillers

    Capecchi, Eliana / Tomaino, Elisabetta / Piccinino, Davide / Kidibule, Peter Elias / Fernández-Lobato, Maria / Spinelli, Daniele / Pogni, Rebecca / Cabado, Ana Garcia / Lago, Jorge / Saladino, Raffaele

    Biomacromolecules. 2022 July 25, v. 23, no. 8

    2022  

    Abstract: Lignin nanoparticles containing saccharides from fishery wastes were prepared as sustainable biofillers for advanced materials. Organosolv lignin and Kraft lignin were used as polyphenol components in association with chitosan and chitooligosaccharides. ... ...

    Abstract Lignin nanoparticles containing saccharides from fishery wastes were prepared as sustainable biofillers for advanced materials. Organosolv lignin and Kraft lignin were used as polyphenol components in association with chitosan and chitooligosaccharides. The chemophysical and biological activities of lignin/saccharide nanoparticles, such as UV-shielding, antioxidant, and antimicrobial activities, were found to be dependent on both molecular weight and deacetylation degree of saccharides, with the best performance being obtained in the presence of low-molecular-weight and highly deacetylated chitooligosaccharides. In addition, chitooligosaccharides showed a synergistic antioxidant effect with lignins, associated with antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive).
    Keywords Escherichia coli ; Staphylococcus aureus ; antimicrobial properties ; antioxidant activity ; antioxidants ; chitooligosaccharides ; chitosan ; fisheries ; lignin ; molecular weight ; polyphenols
    Language English
    Dates of publication 2022-0725
    Size p. 3154-3164.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1526-4602
    DOI 10.1021/acs.biomac.2c00236
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  9. Article: Endo

    Kidibule, Peter Elias / Santos-Moriano, Paloma / Plou, Francisco Jose / Fernández-Lobato, María

    Biotechnology reports (Amsterdam, Netherlands)

    2020  Volume 27, Page(s) e00500

    Abstract: The biological activity of chitooligosaccharides (COS) has made them targets for industrial and medical sectors. In this work, ...

    Abstract The biological activity of chitooligosaccharides (COS) has made them targets for industrial and medical sectors. In this work,
    Language English
    Publishing date 2020-07-04
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 2801018-8
    ISSN 2215-017X
    ISSN 2215-017X
    DOI 10.1016/j.btre.2020.e00500
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  10. Article ; Online: Nanoparticles of Lignins and Saccharides from Fishery Wastes as Sustainable UV-Shielding, Antioxidant, and Antimicrobial Biofillers.

    Capecchi, Eliana / Tomaino, Elisabetta / Piccinino, Davide / Kidibule, Peter Elias / Fernández-Lobato, Maria / Spinelli, Daniele / Pogni, Rebecca / Cabado, Ana Garcia / Lago, Jorge / Saladino, Raffaele

    Biomacromolecules

    2022  Volume 23, Issue 8, Page(s) 3154–3164

    Abstract: Lignin nanoparticles containing saccharides from fishery wastes were prepared as sustainable biofillers for advanced materials. Organosolv lignin and Kraft lignin were used as polyphenol components in association with chitosan and chitooligosaccharides. ... ...

    Abstract Lignin nanoparticles containing saccharides from fishery wastes were prepared as sustainable biofillers for advanced materials. Organosolv lignin and Kraft lignin were used as polyphenol components in association with chitosan and chitooligosaccharides. The chemophysical and biological activities of lignin/saccharide nanoparticles, such as UV-shielding, antioxidant, and antimicrobial activities, were found to be dependent on both molecular weight and deacetylation degree of saccharides, with the best performance being obtained in the presence of low-molecular-weight and highly deacetylated chitooligosaccharides. In addition, chitooligosaccharides showed a synergistic antioxidant effect with lignins, associated with antimicrobial activity against
    MeSH term(s) Anti-Bacterial Agents ; Anti-Infective Agents/pharmacology ; Antioxidants/pharmacology ; Chitin ; Escherichia coli ; Fisheries ; Lignin/pharmacology ; Nanoparticles
    Chemical Substances Anti-Bacterial Agents ; Anti-Infective Agents ; Antioxidants ; Chitin (1398-61-4) ; Lignin (9005-53-2)
    Language English
    Publishing date 2022-07-25
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1526-4602
    ISSN (online) 1526-4602
    DOI 10.1021/acs.biomac.2c00236
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top