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Sample records for lyase electronic resource

  1. Purification of L-glutamate-dependent citrate lyase from Clostridium sphenoides and electron microscopic analysis of citrate lyase isolated from Rhodopseudomonas gelatinosa, Streptococcus diacetilactis and C. sphenoides.

    Science.gov (United States)

    Antranikian, G; Klinner, C; Kümmel, A; Schwanitz, D; Zimmermann, T; Mayer, F; Gottschalk, G

    1982-08-01

    Citrate lyase from Clostridium sphenoides was purified 72-fold with a yield of 11%. In contrast to citrate lyase from other sources the activity of this enzyme was strictly dependent on the presence of L-glutamate. The purified enzyme was only stable in the presence of 150 mM L-glutamate or 7 mM L-glutamate plus glycerol, sucrose or bovine serum albumin. Changes of the L-glutamate pool and of enzyme activity in growing cells of C. sphenoides indicated that citrate lyase activity in this organism was regulated by the intracellular L-glutamate concentration. Citrate lyase isolated from C. sphenoides, Rhodopseudomonas gelatinosa and Streptococcus diacetilactis was investigated by electron microscopy using the negative staining technique. Three different projections of enzyme molecules were observed: 'star' form, 'ring' form and 'triangle' form. In samples from R. gelatinosa and S. diacetilactis, star and ring forms occurred in a ratio of about 1:9. Using the enzyme from S. diacetilactis it was demonstrated that this ratio could be altered in favour of the star form by the addition of citrate or tricarballylate. The triangle form was observed in less than 1% of all evaluated molecules and may represent a transition form. In lyase samples from C. sphenoides there existed a correlation between enzyme activity and the proportion of stars and rings at varying concentrations of L-glutamate.

  2. Selection of Electronic Resources.

    Science.gov (United States)

    Weathers, Barbara

    1998-01-01

    Discusses the impact of electronic resources on collection development; selection of CD-ROMs, (platform, speed, video and sound, networking capability, installation and maintenance); selection of laser disks; and Internet evaluation (accuracy of content, authority, objectivity, currency, technical characteristics). Lists Web sites for evaluating…

  3. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  4. Electronic Resource Management and Design

    Science.gov (United States)

    Abrams, Kimberly R.

    2015-01-01

    We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

  5. Electronic Resource Management and Design

    Science.gov (United States)

    Abrams, Kimberly R.

    2015-01-01

    We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

  6. Managing electronic resources a LITA guide

    CERN Document Server

    Weir, Ryan O

    2012-01-01

    Informative, useful, current, Managing Electronic Resources: A LITA Guide shows how to successfully manage time, resources, and relationships with vendors and staff to ensure personal, professional, and institutional success.

  7. Electronic Resources Management Project Presentation 2012

    KAUST Repository

    Ramli, Rindra M.

    2012-11-05

    This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration is to consolidate all electronic resources into a single and centralized location. This would allow for better information sharing among library staff.

  8. Implementing CORAL: An Electronic Resource Management System

    Science.gov (United States)

    Whitfield, Sharon

    2011-01-01

    A 2010 electronic resource management survey conducted by Maria Collins of North Carolina State University and Jill E. Grogg of University of Alabama Libraries found that the top six electronic resources management priorities included workflow management, communications management, license management, statistics management, administrative…

  9. Implementing CORAL: An Electronic Resource Management System

    Science.gov (United States)

    Whitfield, Sharon

    2011-01-01

    A 2010 electronic resource management survey conducted by Maria Collins of North Carolina State University and Jill E. Grogg of University of Alabama Libraries found that the top six electronic resources management priorities included workflow management, communications management, license management, statistics management, administrative…

  10. Resource Letter: TE-1: Teaching electronics

    Science.gov (United States)

    Henry, Dennis C.

    2002-01-01

    This Resource Letter examines the evolution, roles, and content of courses in electronics in the undergraduate physics curriculum, and provides a guide to resources for faculty teaching such courses. It concludes with a brief section addressing problems of electromagnetic interference in electronic systems, and provides an introduction to the literature and practice of electromagnetic compatibility. I have included textbooks, reference books, articles, collections of laboratory experiments and projects, sources of equipment and parts, software packages, videos, and websites.

  11. CyanoLyase: a database of phycobilin lyase sequences, motifs and functions.

    Science.gov (United States)

    Bretaudeau, Anthony; Coste, François; Humily, Florian; Garczarek, Laurence; Le Corguillé, Gildas; Six, Christophe; Ratin, Morgane; Collin, Olivier; Schluchter, Wendy M; Partensky, Frédéric

    2013-01-01

    CyanoLyase (http://cyanolyase.genouest.org/) is a manually curated sequence and motif database of phycobilin lyases and related proteins. These enzymes catalyze the covalent ligation of chromophores (phycobilins) to specific binding sites of phycobiliproteins (PBPs). The latter constitute the building bricks of phycobilisomes, the major light-harvesting systems of cyanobacteria and red algae. Phycobilin lyases sequences are poorly annotated in public databases. Sequences included in CyanoLyase were retrieved from all available genomes of these organisms and a few others by similarity searches using biochemically characterized enzyme sequences and then classified into 3 clans and 32 families. Amino acid motifs were computed for each family using Protomata learner. CyanoLyase also includes BLAST and a novel pattern matching tool (Protomatch) that allow users to rapidly retrieve and annotate lyases from any new genome. In addition, it provides phylogenetic analyses of all phycobilin lyases families, describes their function, their presence/absence in all genomes of the database (phyletic profiles) and predicts the chromophorylation of PBPs in each strain. The site also includes a thorough bibliography about phycobilin lyases and genomes included in the database. This resource should be useful to scientists and companies interested in natural or artificial PBPs, which have a number of biotechnological applications, notably as fluorescent markers.

  12. Electronic Resources Management System: Recommendation Report 2017

    KAUST Repository

    Ramli, Rindra M.

    2017-05-01

    This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system as potential replacements namely: Proquest 360 Resource Manager, Ex Libris Alma and Open Source CORAL ERMS. After comparing and trialling the systems, it was decided to go for Proquest 360 Resource Manager.

  13. Library Training to Promote Electronic Resource Usage

    DEFF Research Database (Denmark)

    Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

    2017-01-01

    Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...

  14. Reviewing the Electronic Resources & Libraries Conference

    Science.gov (United States)

    Tijerina, Bonnie

    2008-01-01

    The third Electronic Resources & Libraries (ER&L) conference gathered at Georgia Institute of Technology's Global Learning and Conference Center in Atlanta, Georgia, March 18-21, 2008. Over 360 attendees, from six countries and from 80% of the United States, represented their libraries and organizations resulting in a diverse and…

  15. Making sense of the electronic resource marketplace: trends in health-related electronic resources.

    Science.gov (United States)

    Blansit, B D; Connor, E

    1999-07-01

    Changes in the practice of medicine and technological developments offer librarians unprecedented opportunities to select and organize electronic resources, use the Web to deliver content throughout the organization, and improve knowledge at the point of need. The confusing array of available products, access routes, and pricing plans makes it difficult to anticipate the needs of users, identify the top resources, budget effectively, make sound collection management decisions, and organize the resources effectively and seamlessly. The electronic resource marketplace requires much vigilance, considerable patience, and continuous evaluation. There are several strategies that librarians can employ to stay ahead of the electronic resource curve, including taking advantage of free trials from publishers; marketing free trials and involving users in evaluating new products; watching and testing products marketed to the clientele; agreeing to beta test new products and services; working with aggregators or republishers; joining vendor advisory boards; benchmarking institutional resources against five to eight competitors; and forming or joining a consortium for group negotiating and purchasing. This article provides a brief snapshot of leading biomedical resources; showcases several libraries that have excelled in identifying, acquiring, and organizing electronic resources; and discusses strategies and trends of potential interest to biomedical librarians, especially those working in hospital settings.

  16. Electronic resource management systems a workflow approach

    CERN Document Server

    Anderson, Elsa K

    2014-01-01

    To get to the bottom of a successful approach to Electronic Resource Management (ERM), Anderson interviewed staff at 11 institutions about their ERM implementations. Among her conclusions, presented in this issue of Library Technology Reports, is that grasping the intricacies of your workflow-analyzing each step to reveal the gaps and problems-at the beginning is crucial to selecting and implementing an ERM. Whether the system will be used to fill a gap, aggregate critical data, or replace a tedious manual process, the best solution for your library depends on factors such as your current soft

  17. Studies on pectin lyase

    NARCIS (Netherlands)

    Houdenhoven, van F.E.A.

    1975-01-01

    The pectin lyase activity in the commercial enzyme preparation Ultrazym originates from more then one type of enzyme; two of them, accounting for 95 % of the total activity, have been completely purified. As purity criteria specific activity, polyacrylamide disc gel electrophoresis and SDS

  18. Studies on pectin lyase

    NARCIS (Netherlands)

    Houdenhoven, van F.E.A.

    1975-01-01

    The pectin lyase activity in the commercial enzyme preparation Ultrazym originates from more then one type of enzyme; two of them, accounting for 95 % of the total activity, have been completely purified. As purity criteria specific activity, polyacrylamide disc gel electrophoresis and SDS electroph

  19. Electronic Resource Management System. Vernetzung von Lizenzinformationen

    Directory of Open Access Journals (Sweden)

    Michaela Selbach

    2014-12-01

    Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

  20. Utilization of electronic information resources by academic staff at ...

    African Journals Online (AJOL)

    Utilization of electronic information resources by academic staff at Makerere University. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... It examined the academic staff awareness of the resources available, the types ...

  1. Effectiveness Analysis of Electronic Resources at the Hacettepe University

    OpenAIRE

    2011-01-01

    It is important to collect and analyze the usage data of electronic databases and periodicals in order to make policies regarding the composition, improvement and more extensive utilization of electronic resources of libraries. The aim of this study is to investigate how efficiently the full text accessible electronic resources of Hacettepe University Libraries are used. For this purpose the usage data obtained from COUNTER Software regarding the electronic databases to which Hacettepe Univer...

  2. The Study of Analytical Model of Library Electronic Resources Usage-A Case of Medical Electronic Resources

    OpenAIRE

    Chung-Yen Yu; Jiann-Cherng Shieh

    2014-01-01

    With the advents of internet, the importance of electronic resources is growing. Due to the increasing expensiveness of electronic resources, university libraries normally received budgets from parent institutions annually. They necessarily applied effective and systematic methods for decision making in electronic resources purchase or re-subscription. However, there are some difficulties in practices: First of all, libraries are unable to receive user records; second, the COUNTER statistics ...

  3. The Role of the Acquisitions Librarian in Electronic Resources Management

    Science.gov (United States)

    Pomerantz, Sarah B.

    2010-01-01

    With the ongoing shift to electronic formats for library resources, acquisitions librarians, like the rest of the profession, must adapt to the rapidly changing landscape of electronic resources by keeping up with trends and mastering new skills related to digital publishing, technology, and licensing. The author sought to know what roles…

  4. Electronic resources preferred by pediatric hospitalists for clinical care.

    Science.gov (United States)

    Beck, Jimmy B; Tieder, Joel S

    2015-10-01

    There is little research on pediatric hospitalists' use of evidence-based resources. The aim of this study was to determine the electronic resources that pediatric hospitalists prefer. Using a web-based survey, the authors determined hospitalists' preferred electronic resources, as well as their attitudes toward lifelong learning, practice, and experience characteristics. One hundred sixteen hospitalists completed the survey. The most preferred resource for general information, patient handouts, and treatment was UpToDate. Online search engines were ranked second for general information and patient handouts. Pediatric hospitalists tend to utilize less rigorous electronic resources such as UpToDate and Google. These results can set a platform for discussing the quality of resources that pediatric hospitalists use.

  5. Cataloging and Indexing of Electronic Information Resources

    Science.gov (United States)

    2003-04-01

    digital library, but it facilitates the exchange of these objects among digital libraries . METS provides an XML DTD that can point to metadata in other...International Federation of Library Associations and Institutions (IFLA). (2002). Digital Libraries : Metadata Resources. Retrieved May 3, 2002 from the

  6. Spectroscopic studies on the active site of hydroperoxide lyase : the influence of detergents on its conformation

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.

    2001-01-01

    Expression of high quantities of alfalfa hydroperoxide lyase in Escherichia coli made it possible to study its active site and structure in more detail. Circular dichroism (CD) spectra showed that hydroperoxide lyase consists for about 75% of alpha-helices. Electron paramagnetic resonance (EPR) spec

  7. Adoption and use of electronic information resources by medical ...

    African Journals Online (AJOL)

    ... were analysed with descriptive Statistics(Simple percentage and frequency count). ... for doing assignment, Google search, for personal development, and getting ... major problems encountered when using electronic Information Resources.

  8. Euler European Libraries and Electronic Resources in Mathematical Sciences

    CERN Document Server

    The Euler Project. Karlsruhe

    The European Libraries and Electronic Resources (EULER) Project in Mathematical Sciences provides the EulerService site for searching out "mathematical resources such as books, pre-prints, web-pages, abstracts, proceedings, serials, technical reports preprints) and NetLab (for Internet resources), this outstanding engine is capable of simple, full, and refined searches. It also offers a browse option, which responds to entries in the author, keyword, and title fields. Further information about the Project is provided at the EULER homepage.

  9. Building an electronic resource collection a practical guide

    CERN Document Server

    Lee, Stuart D

    2004-01-01

    This practical book guides information professionals step-by-step through building and managing an electronic resource collection. It outlines the range of electronic products currently available in abstracting and indexing, bibliographic, and other services and then describes how to effectively select, evaluate and purchase them.

  10. Why and How to Measure the Use of Electronic Resources

    Directory of Open Access Journals (Sweden)

    Jean Bernon

    2008-11-01

    Full Text Available A complete overview of library activity implies a complete and reliable measurement of the use of both electronic resources and printed materials. This measurement is based on three sets of definitions: document types, use types and user types. There is a common model of definitions for printed materials, but a lot of questions and technical issues remain for electronic resources. In 2006 a French national working group studied these questions. It relied on the COUNTER standard, but found it insufficient and pointed out the need for local tools such as web markers and deep analysis of proxy logs. Within the French national consortium COUPERIN, a new working group is testing ERMS, SUSHI standards, Shibboleth authentication, along with COUNTER standards, to improve the counting of the electronic resources use. At this stage this counting is insufficient and its improvement will be a European challenge for the future.

  11. Access to electronic resources by visually impaired people

    Directory of Open Access Journals (Sweden)

    Jenny Craven

    2003-01-01

    Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

  12. The Study of Analytical Model of Library Electronic Resources Usage-A Case of Medical Electronic Resources

    Directory of Open Access Journals (Sweden)

    Chung-Yen Yu

    2014-10-01

    Full Text Available With the advents of internet, the importance of electronic resources is growing. Due to the increasing expensiveness of electronic resources, university libraries normally received budgets from parent institutions annually. They necessarily applied effective and systematic methods for decision making in electronic resources purchase or re-subscription. However, there are some difficulties in practices: First of all, libraries are unable to receive user records; second, the COUNTER statistics does not include details about users and their affiliation. As a result, one cannot conduct advanced user analysis based on the usage of users, institutions, and departments. To overcome the difficulties, this study presents a feasible model to analyze electronic resource usage effectively and flexibly. We set up a proxy server to collect actual usage raw data. By analyzing items in internet browsing records, associated with original library automatic system, this study aims at exploring how to use effective ways to analyze big data of website log data. We also propose the process of how original data to be transformed, cleared, integrated, and demonstrated. This study adopted a medical university library and its subscription of medical electronic resources as a case. Our data analysis includes (1 year of subscription,(2 title of journal, (3 affiliation, (4 subjects, and (5 specific journal requirements, etc. The findings of the study are contributed to obtain further understanding in policy making and user behavior analysis. The integrated data provides multiple applications in informatics research, information behavior, bibliomining, presenting diverse views and extended issues for further discussion.

  13. Practical guide to electronic resources in the humanities

    CERN Document Server

    Dubnjakovic, Ana

    2010-01-01

    From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

  14. Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

    Directory of Open Access Journals (Sweden)

    Sanna Torma

    2004-01-01

    Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

  15. Providing Access to Electronic Information Resources in Further Education

    Science.gov (United States)

    Banwell, Linda; Ray, Kathryn; Coulson, Graham; Urquhart, Christine; Lonsdale, Ray; Armstrong, Chris; Thomas, Rhian; Spink, Sin; Yeoman, Alison; Fenton, Roger; Rowley, Jennifer

    2004-01-01

    This article aims to provide a baseline for future studies on the provision and support for the use of digital or electronic information services (EIS) in further education. The analysis presented is based on a multi-level model of access, which encompasses access to and availability of information and communication technology (ICT) resources,…

  16. ANALYTICAL REVIEW OF ELECTRONIC RESOURCES FOR THE STUDY OF LATIN

    Directory of Open Access Journals (Sweden)

    Olena Yu. Balalaieva

    2014-04-01

    Full Text Available The article investigates the current state of development of e-learning content in the Latin language. It is noted that the introduction of ICT in the educational space has expanded the possibility of studying Latin, opened access to digital libraries resources, made it possible to use scientific and educational potential and teaching Latin best practices of world's leading universities. A review of foreign and Ukrainian information resources and electronic editions for the study of Latin is given. Much attention was paid to the didactic potential of local and online multimedia courses of Latin, electronic textbooks, workbooks of interactive tests and exercises, various dictionaries and software translators, databases and digital libraries. Based on analysis of the world market of educational services and products the main trends in the development of information resources and electronic books are examined. It was found that multimedia courses with interactive exercises or workbooks with interactive tests, online dictionaries and translators are the most widely represented and demanded. The noticeable lagging of Ukrainian education and computer linguistics in quantitative and qualitative measures in this industry is established. The obvious drawback of existing Ukrainian resources and electronic editions for the study of Latin is their noninteractive nature. The prospects of e-learning content in Latin in Ukraine are outlined.

  17. Electronic Commerce Resource Centers. An Industry--University Partnership.

    Science.gov (United States)

    Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

    1999-01-01

    Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

  18. Student Satisfaction with Electronic Library Resources at Wayne State University

    Science.gov (United States)

    Holley, Robert P.; Powell, Ronald R.

    2004-01-01

    This paper reports the results of a survey of student satisfaction with electronic library resources other than the online catalog at Wayne State University. Undertaken in Fall Term 2000 as a class project for a marketing course, a student team designed, administered, and analyzed a survey of a random sample of students. Almost 40% of the…

  19. Electronic Commerce Resource Centers. An Industry--University Partnership.

    Science.gov (United States)

    Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

    1999-01-01

    Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

  20. Technical Communicator: A New Model for the Electronic Resources Librarian?

    Science.gov (United States)

    Hulseberg, Anna

    2016-01-01

    This article explores whether technical communicator is a useful model for electronic resources (ER) librarians. The fields of ER librarianship and technical communication (TC) originated and continue to develop in relation to evolving technologies. A review of the literature reveals four common themes for ER librarianship and TC. While the…

  1. Providing Access to Electronic Information Resources in Further Education

    Science.gov (United States)

    Banwell, Linda; Ray, Kathryn; Coulson, Graham; Urquhart, Christine; Lonsdale, Ray; Armstrong, Chris; Thomas, Rhian; Spink, Sin; Yeoman, Alison; Fenton, Roger; Rowley, Jennifer

    2004-01-01

    This article aims to provide a baseline for future studies on the provision and support for the use of digital or electronic information services (EIS) in further education. The analysis presented is based on a multi-level model of access, which encompasses access to and availability of information and communication technology (ICT) resources,…

  2. Evaluating the appropriateness of electronic information resources for learning.

    Science.gov (United States)

    Saparova, Dinara; Nolan, Nathanial S

    2016-01-01

    Current US medical students have begun to rely on electronic information repositories-such as UpToDate, AccessMedicine, and Wikipedia-for their pre-clerkship medical education. However, it is unclear whether these resources are appropriate for this level of learning due to factors involving information quality, level of evidence, and the requisite knowledgebase. This study evaluated appropriateness of electronic information resources from a novel perspective: amount of mental effort learners invest in interactions with these resources and effects of the experienced mental effort on learning. Eighteen first-year medical students read about three unstudied diseases in the above-mentioned resources (a total of fifty-four observations). Their eye movement characteristics (i.e., fixation duration, fixation count, visit duration, and task-evoked pupillary response) were recorded and used as psychophysiological indicators of the experienced mental effort. Post reading, students' learning was assessed with multiple-choice tests. Eye metrics and test results constituted quantitative data analyzed according to the repeated Latin square design. Students' perceptions of interacting with the information resources were also collected. Participants' feedback during semi-structured interviews constituted qualitative data and was reviewed, transcribed, and open coded for emergent themes. Compared to AccessMedicine and Wikipedia, UpToDate was associated with significantly higher values of eye metrics, suggesting learners experienced higher mental effort. No statistically significant difference between the amount of mental effort and learning outcomes was found. More so, descriptive statistical analysis of the knowledge test scores suggested similar levels of learning regardless of the information resource used. Judging by the learning outcomes, all three information resources were found appropriate for learning. UpToDate, however, when used alone, may be less appropriate for first

  3. MODEL OF AN ELECTRONIC EDUCATIONAL RESOURCE OF NEW GENERATION

    Directory of Open Access Journals (Sweden)

    Anatoliy V. Loban

    2016-01-01

    Full Text Available The mathematical structure of the modular architecture of an electronic educational resource (EER of new generation, which allows to decompose the process of studying the subjects of the course at a hierarchically ordered set of data (knowledge and procedures for manipulating them, to determine the roles of participants of process of training of and technology the development and use of EOR in the study procrate.

  4. Evaluating increased resource use in fibromyalgia using electronic health records

    Directory of Open Access Journals (Sweden)

    Margolis JM

    2016-11-01

    Full Text Available Jay M Margolis,1 Elizabeth T Masters,2 Joseph C Cappelleri,3 David M Smith,1 Steven Faulkner4 1Truven Health Analytics, Life Sciences, Outcomes Research, Bethesda, MD, 2Pfizer Inc, Outcomes & Evidence, New York, NY, 3Pfizer Inc, Statistics, Groton, CT, 4Pfizer Inc, North American Medical Affairs, Medical Outcomes Specialists, St Louis, MO, USA Objective: The management of fibromyalgia (FM, a chronic musculoskeletal disease, remains challenging, and patients with FM are often characterized by high health care resource utilization. This study sought to explore potential drivers of all-cause health care resource utilization and other factors associated with high resource use, using a large electronic health records (EHR database to explore data from patients diagnosed with FM. Methods: This was a retrospective analysis of de-identified EHR data from the Humedica database. Adults (≥18 years with FM were identified based on ≥2 International Classification of Diseases, Ninth Revision codes for FM (729.1 ≥30 days apart between January 1, 2008 and December 31, 2012 and were required to have evidence of ≥12 months continuous care pre- and post-index; first FM diagnosis was the index event; 12-month pre- and post-index reporting periods. Multivariable analysis evaluated relationships between variables and resource utilization. Results: Patients were predominantly female (81.4%, Caucasian (87.7%, with a mean (standard deviation age of 54.4 (14.8 years. The highest health care resource utilization was observed for the categories of “medication orders” and “physician office visits,” with 12-month post-index means of 21.2 (21.5 drug orders/patient and 15.1 (18.1 office visits/patient; the latter accounted for 73.3% of all health care visits. Opioids were the most common prescription medication, 44.3% of all patients. The chance of high resource use was significantly increased (P<0.001 26% among African-Americans vs Caucasians and for patients

  5. Online Electronic Resources and Slovenian Bibliography: a Case Study

    Directory of Open Access Journals (Sweden)

    Daniela Škerget

    2014-09-01

    Full Text Available AbstractConsidering the fact that the number of publications available online only is growing, the question whether to include online electronic resources into the Slovenian bibliography, and if so, in which way, and what are the requirements for the inclusion, is raised. To answer these questions, the research on the growth of the Slovenian online scientific production in comparison with production in printed form was conducted in the case of original scientific articles. Results showed a rapid growth of the number of original scientific articles available online only, which indicates the necessity to form a separate Slovenian bibliography of online resources. The selection criteria for the Slovenian bibliography of online resources are also presented. This kind of bibliography would, along with the informational value, add to the historical value of intellectual production in a given time frame, enriched with a link to the resource preserved in another location (archive, repository, in case of unavailability of the resource on its original location.

  6. Journals, Data and Abstracts Make an Integrated Electronic Resource

    Science.gov (United States)

    Boyce, P.

    1996-12-01

    Astronomy now has an integrated, Web-based information resource for research papers, data and bibliographic information. The major scholarly research journals, a comprehensive abstract service and the astronomical data centers are now linked together to provide an information resource which is not available to most other scientific disciplines. As of January, 1997, the Astrophysical Journal joins the ApJ Letters on the Web. Astronomy and Astrophysics Supplements now has a page image version. Elsevier's electronic journal New Astronomy has recently made its appearance. Over forty percent of the new peer-reviewed, astronomical literature is now available electronically. The main Astronomy and Astrophysics journal, the Astronomical Journal and others will be available by 1998, at which point ninety percent of the literature will be available electronically, a figure not approached by any other scientific discipline. With so many different sources, one of the challenges has been to integrate the on-line, peer-reviewed literature into a resource which serves the astronomical community in a unified and coherent manner. Following the lead of the AAS, the major publishers have chosen to rely upon the NASA-supported Astrophysics Data System (ADS) and the astronomical data centers to provide the means by which the various separate journals can interoperate. The data centers and the ADS have developed unique identification codes for journal articles. By adopting the existing standard "bibcodes" and integrating them into their WWW links, each of the major astronomical journals are able to link to the abstracts of most of the referenced articles. Since the ADS also serves as an on-line repository for page images of the past twenty years of the major astronomical journals, the full text of many of the referenced articles are available, too. The articles in the ADS have recently been linked through their references, both forward and backward in time. With the "bibcode" providing

  7. Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

    Science.gov (United States)

    Shao, Fang

    The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

  8. Resources

    Science.gov (United States)

    ... resources Alzheimer's - resources Anorexia nervosa - resources Arthritis - resources Asthma and allergy - resources Autism - resources Blindness - resources BPH - resources Breastfeeding - resources Bulimia - resources Burns - resources Cancer - resources Cerebral ...

  9. Discipline, Availability of Electronic Resources and the Use of Finnish National Electronic Library-- FinELib

    Science.gov (United States)

    Törmä, Sanna; Vakkari, Pertti

    2004-01-01

    This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib), Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic…

  10. End-of-life resource recovery from emerging electronic products

    DEFF Research Database (Denmark)

    Parajuly, Keshav; Habib, Komal; Cimpan, Ciprian

    2016-01-01

    of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial......Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case...... at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best...

  11. Electronic Resources and Mission Creep: Reorganizing the Library for the Twenty-First Century

    Science.gov (United States)

    Stachokas, George

    2009-01-01

    The position of electronic resources librarian was created to serve as a specialist in the negotiation of license agreements for electronic resources, but mission creep has added more functions to the routine work of electronic resources such as cataloging, gathering information for collection development, and technical support. As electronic…

  12. Effects of Electronic Information Resources Skills Training for Lecturers on Pedagogical Practices and Research Productivity

    Science.gov (United States)

    Bhukuvhani, Crispen; Chiparausha, Blessing; Zuvalinyenga, Dorcas

    2012-01-01

    Lecturers use various electronic resources at different frequencies. The university library's information literacy skills workshops and seminars are the main sources of knowledge of accessing electronic resources. The use of electronic resources can be said to have positively affected lecturers' pedagogical practices and their work in general. The…

  13. Rhamnogalacturonan lyase reveals a unique three-domain modular structure for polysaccharide lyase family 4

    DEFF Research Database (Denmark)

    McDonough, Michael A.; Kadirvelraj, Renuka; Harris, Pernille

    2004-01-01

    Rhamnogalacturonan lyase (RG-lyase) specifically recognizes and cleaves alpha-1,4 glycosidic bonds between L-rhamnose and D-galacturonic acids in the backbone of rhamno galacturonan-I, a major component of the plant cell wall polysaccharide, pectin. The three-dimensional structure of RG-lyase fro...... structural homology to non-catalytic domains from other carbohydrate active enzymes.......Rhamnogalacturonan lyase (RG-lyase) specifically recognizes and cleaves alpha-1,4 glycosidic bonds between L-rhamnose and D-galacturonic acids in the backbone of rhamno galacturonan-I, a major component of the plant cell wall polysaccharide, pectin. The three-dimensional structure of RG-lyase from...... Aspergillus aculeatus has been determined to 1.5 Angstrom resolution representing the first known structure from polysaccharide lyase family 4 and of an enzyme with this catalytic specificity. The 508-amino acid polypeptide displays a unique arrangement of three distinct modular domains. Each domain shows...

  14. Electronic Document Management: A Human Resource Management Case Study

    Directory of Open Access Journals (Sweden)

    Thomas Groenewald

    2004-11-01

    Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

  15. Electronic Safety Resource Tools -- Supporting Hydrogen and Fuel Cell Commercialization

    Energy Technology Data Exchange (ETDEWEB)

    Barilo, Nick F.

    2014-09-29

    The Pacific Northwest National Laboratory (PNNL) Hydrogen Safety Program conducted a planning session in Los Angeles, CA on April 1, 2014 to consider what electronic safety tools would benefit the next phase of hydrogen and fuel cell commercialization. A diverse, 20-person team led by an experienced facilitator considered the question as it applied to the eight most relevant user groups. The results and subsequent evaluation activities revealed several possible resource tools that could greatly benefit users. The tool identified as having the greatest potential for impact is a hydrogen safety portal, which can be the central location for integrating and disseminating safety information (including most of the tools identified in this report). Such a tool can provide credible and reliable information from a trustworthy source. Other impactful tools identified include a codes and standards wizard to guide users through a series of questions relating to application and specific features of the requirements; a scenario-based virtual reality training for first responders; peer networking tools to bring users from focused groups together to discuss and collaborate on hydrogen safety issues; and a focused tool for training inspectors. Table ES.1 provides results of the planning session, including proposed new tools and changes to existing tools.

  16. Controlling user access to electronic resources without password

    Science.gov (United States)

    Smith, Fred Hewitt

    2015-06-16

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

  17. Impact of different alginate lyases on combined cellulase–lyase saccharification of brown seaweed

    DEFF Research Database (Denmark)

    Manns, Dirk Martin; Nyffenegger, Christian; Saake, B.

    2016-01-01

    Two bacterial polysaccharide lyase (PL) family 7 alginate lyases (EC 4.2.2.-) from Sphingomonas sp. (SALy) and Flavobacterium sp. (FALy), respectively, were selected for heterologous, monocomponent expression in Escherichia coli. The thermal stability, pH, and temperature reaction optima and subs...... solubilization of sulfated fucoidan, whereas most of the nitrogen was recovered in the residual seaweed solids....

  18. The Internet School of Medicine: use of electronic resources by medical trainees and the reliability of those resources.

    Science.gov (United States)

    Egle, Jonathan P; Smeenge, David M; Kassem, Kamal M; Mittal, Vijay K

    2015-01-01

    Electronic sources of medical information are plentiful, and numerous studies have demonstrated the use of the Internet by patients and the variable reliability of these sources. Studies have investigated neither the use of web-based resources by residents, nor the reliability of the information available on these websites. A web-based survey was distributed to surgical residents in Michigan and third- and fourth-year medical students at an American allopathic and osteopathic medical school and a Caribbean allopathic school regarding their preferred sources of medical information in various situations. A set of 254 queries simulating those faced by medical trainees on rounds, on a written examination, or during patient care was developed. The top 5 electronic resources cited by the trainees were evaluated for their ability to answer these questions accurately, using standard textbooks as the point of reference. The respondents reported a wide variety of overall preferred resources. Most of the 73 responding medical trainees favored textbooks or board review books for prolonged studying, but electronic resources are frequently used for quick studying, clinical decision-making questions, and medication queries. The most commonly used electronic resources were UpToDate, Google, Medscape, Wikipedia, and Epocrates. UpToDate and Epocrates had the highest percentage of correct answers (47%) and Wikipedia had the lowest (26%). Epocrates also had the highest percentage of wrong answers (30%), whereas Google had the lowest percentage (18%). All resources had a significant number of questions that they were unable to answer. Though hardcopy books have not been completely replaced by electronic resources, more than half of medical students and nearly half of residents prefer web-based sources of information. For quick questions and studying, both groups prefer Internet sources. However, the most commonly used electronic resources fail to answer clinical queries more than half

  19. Structural Insights Into The Bacterial Carbon-Phosphorus Lyase Machinery

    DEFF Research Database (Denmark)

    Brodersen, Ditlev Egeskov

    structural features. The complex contains at least two different active sites and suggest a revision of current models of carbon-phosphorus bond cleavage. Using electron microscopy, we map the binding site of an additional protein subunit, which may use ATP for driving conformational changes during...... the proteins encoded in the phn operon act in concert to catabolise phosphonate remain unknown. We have determined the crystal structure of a 240 kDa Escherichia coli carbon-phosphorus lyase core complex at 1.7 Å and show that it comprises a highly intertwined network of subunits with several unexpected...

  20. Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

    Science.gov (United States)

    Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

    2014-01-01

    This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

  1. Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

    Science.gov (United States)

    Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

    2014-01-01

    This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

  2. Electronic resource management practical perspectives in a new technical services model

    CERN Document Server

    Elguindi, Anne

    2012-01-01

    A significant shift is taking place in libraries, with the purchase of e-resources accounting for the bulk of materials spending. Electronic Resource Management makes the case that technical services workflows need to make a corresponding shift toward e-centric models and highlights the increasing variety of e-formats that are forcing new developments in the field.Six chapters cover key topics, including: technical services models, both past and emerging; staffing and workflow in electronic resource management; implementation and transformation of electronic resource management systems; the ro

  3. Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

    Science.gov (United States)

    Hulseberg, Anna; Monson, Sarah

    2009-01-01

    Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

  4. Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

    Science.gov (United States)

    Hulseberg, Anna; Monson, Sarah

    2009-01-01

    Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

  5. The Relevancy of Graduate Curriculum to Human Resource Professionals' Electronic Communication.

    Science.gov (United States)

    Hoell, Robert C.; Henry, Gordon O.

    2003-01-01

    Electronic communications of human resource professionals and the content of 23 university human resource management courses were categorized using the Human Resource Certification Institute's body of knowledge. Differences between proportion of topics discussed and topics covered in curricula suggest some topics are over- or undertaught.…

  6. 2015 Utilization of Electronic Information Resources in Ramat ...

    African Journals Online (AJOL)

    intensely powerful and has permeated all segments and ... Web (WWW) and the internet to make information more accessible. On the other ... access points on the campus and computer literacy is till .... resources are often faster to consult than.

  7. Remote Electronic Resources and the OPAC: Illustrated by the Unisa Library Experience.

    Science.gov (United States)

    Van der Merwe, Ina; Van Eeden, Welna; Hartzer, Sandra

    This paper describes the Unisa (University of South Africa) Library's experience with cataloging remote electronic resources, including electronic journals, electronic text files, online databases, digital images, Unisa campus Web sites, and mailing list discussions. The first section discusses the decision to add bibliographic references for…

  8. Isocitrate lyase localisation in Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Chaves, R S; Herrero, P; Ordiz, I; Angeles del Brio, M; Moreno, F

    1997-10-01

    The isocitrate lyase from Saccharomyces cerevisiae was only located in the cell cytoplasm. This protein was found not to be associated with cell organelles, even under growth conditions that induce peroxisome proliferation. This conclusion is supported by experiments carried out by damaging the protoplast plasma membrane with DEAE-dextran, by differential centrifugation of osmotically lysed protoplast and by using the green fluorescent protein (GFP) of Aequorea victoria as a reporter fusion tag to localise the subcellular compartment to which isocitrate lyase is targeted.

  9. Controlling user access to electronic resources without password

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Fred Hewitt

    2017-08-22

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

  10. An Evaluation of Electronic Product Design Education Using Hypermedia-Resourced Learning Environments

    Science.gov (United States)

    Page, Tom; Thorsteinsson, Gisli

    2006-01-01

    The work outlined here provides a comprehensive report and formative observations of the development and implementation of hypermedia resources for learning and teaching used in conjunction with a managed learning environment (MLE). These resources are used to enhance teaching and learning of an electronics module in product design at final year…

  11. A Study on Developing Evaluation Criteria for Electronic Resources in Evaluation Indicators of Libraries

    Science.gov (United States)

    Noh, Younghee

    2010-01-01

    This study aimed to improve the current state of electronic resource evaluation in libraries. While the use of Web DB, e-book, e-journal, and other e-resources such as CD-ROM, DVD, and micro materials is increasing in libraries, their use is not comprehensively factored into the general evaluation of libraries and may diminish the reliability of…

  12. Managing Selection for Electronic Resources: Kent State University Develops a New System to Automate Selection

    Science.gov (United States)

    Downey, Kay

    2012-01-01

    Kent State University has developed a centralized system that manages the communication and work related to the review and selection of commercially available electronic resources. It is an automated system that tracks the review process, provides selectors with price and trial information, and compiles reviewers' feedback about the resource. It…

  13. Where Do Electronic Books Fit in the College Research Arsenal of Resources?

    Science.gov (United States)

    Barbier, Patricia

    2007-01-01

    Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

  14. Where Do Electronic Books Fit in the College Research Arsenal of Resources?

    Science.gov (United States)

    Barbier, Patricia

    2007-01-01

    Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

  15. MULER: Building an Electronic Resource Management (ERM Solution at York University

    Directory of Open Access Journals (Sweden)

    Aaron August Lupton

    2012-01-01

    Full Text Available Many university libraries now utilize an Electronic Resource Management (ERM system to assist with operations related to electronic resources. An ERM is a relational database containing information such as suppliers, costs, holdings, and renewal dates for electronic resources, both at the database and title levels. While commercial ERM products are widely available, some institutions are custom building their own ERM in- house. This article describes how York University in Toronto, Canada, did just that by building a system called Managing University Library Electronic Resources (MULER. The article details the background and history of how electronic resources were managed pre-MULER; why a new ERM was needed; the planning process; the current and innovative functions of MULER, including integration of MULER data into York University Libraries search and discovery layer, Vufind; subject tagging in MULER; new functions to be added; and lessons learned from the project. Positive and negative implications of choosing an in-house project over paying for a commercial product are also discussed.

  16. Structural insights into the bacterial carbon - phosphorus lyase machinery

    DEFF Research Database (Denmark)

    Seweryn, Paulina; Van, Lan Bich; Kjeldgaard, Morten

    2015-01-01

    –phosphorus (C–P) bond. Despite its importance, the details of how this machinery catabolizes phosphonates remain unknown. Here we determine the crystal structure of the 240-kilodalton Escherichia coli C–P lyase core complex (PhnG–PhnH–PhnI–PhnJ; PhnGHIJ), and show that it is a two-fold symmetric hetero......-octamer comprising an intertwined network of subunits with unexpected self-homologies. It contains two potential active sites that probably couple phosphonate compounds to ATP and subsequently hydrolyse the C–P bond. We map the binding site of PhnK on the complex using electron microscopy, and show that it binds...... to a conserved insertion domain of PhnJ. Our results provide a structural basis for understanding microbial phosphonate breakdown....

  17. The National Site Licensing of Electronic Resources: An Institutional Perspective

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhu

    2011-06-01

    Full Text Available While academic libraries in most countries are struggling to negotiate with publishers and vendors individually or collaboratively via consortia, a few countries have experimented with a different model, national site licensing (NSL. Because NSL often involves government and large-scale collaboration, it has the potential to solve many problems in the complex licensing world. However, not many nations have adopted it. This study uses historical research approach and the comparative case study research method to explore the seemingly low level of adoption. The cases include the Canadian National Site Licensing Project (CNSLP, the United Kingdom’s National Electronic Site Licensing Initiative (NESLI, and the United States, which has not adopted NSL. The theoretical framework guiding the research design and data collection is W. Richard Scott’s institutional theory, which utilizes three supporting pillars—regulative, normative, and cultural-cognitive—to analyze institutional processes. In this study, the regulative pillar and the normative pillar of NSL adoption— an institutional construction and change—are examined. Data were collected from monographs, research articles, government documents, and relevant websites. Based on the analysis of these cases, a preliminary model is proposed for the adoption of NSL. The factors that support a country’s adoption of NSL include the need for new institutions, a centralized educational policy-making system and funding system, supportive political trends, and the tradition of cooperation. The factors that may prevent a country from adopting NSL include decentralized educational policy and funding, diversity and the large number of institutions, the concern for the “Big Deal,” and the concern for monopoly.

  18. Analytical Study of Usage of Electronic Information Resources at Pharmacopoeial Libraries in India

    Directory of Open Access Journals (Sweden)

    Sunil Tyagi

    2014-02-01

    Full Text Available The objective of this study is to know the rate and purpose of the use of e-resource by the scientists at pharmacopoeial libraries in India. Among other things, this study examined the preferences of the scientists toward printed books and journals, electronic information resources, and pattern of using e-resources. Non-probability sampling specially accidental and purposive technique was applied in the collection of primary data through administration of user questionnaire. The sample respondents chosen for the study consists of principle scientific officer, senior scientific officer, scientific officer, and scientific assistant of different division of the laboratories, namely, research and development, pharmaceutical chemistry, pharmacovigilance, pharmacology, pharmacogonosy, and microbiology. The findings of the study reveal the personal experiences and perceptions they have had on practice and research activity using e-resource. The major findings indicate that of the total anticipated participants, 78% indicated that they perceived the ability to use computer for electronic information resources. The data analysis shows that all the scientists belonging to the pharmacopoeial libraries used electronic information resources to address issues relating to drug indexes and compendia, monographs, drugs obtained through online databases, e-journals, and the Internet sources—especially polices by regulatory agencies, contacts, drug promotional literature, and standards.

  19. Connecting knowledge resources to the veterinary electronic health record: opportunities for learning at point of care.

    Science.gov (United States)

    Alpi, Kristine M; Burnett, Heidi A; Bryant, Sheila J; Anderson, Katherine M

    2011-01-01

    Electronic health records (EHRs) provide clinical learning opportunities through quick and contextual linkage of patient signalment, symptom, and diagnosis data with knowledge resources covering tests, drugs, conditions, procedures, and client instructions. This paper introduces the EHR standards for linkage and the partners-practitioners, content publishers, and software developers-necessary to leverage this possibility in veterinary medicine. The efforts of the American Animal Hospital Association (AAHA) Electronic Health Records Task Force to partner with veterinary practice management systems to improve the use of controlled vocabulary is a first step in the development of standards for sharing knowledge at the point of care. The Veterinary Medical Libraries Section (VMLS) of the Medical Library Association's Task Force on Connecting the Veterinary Health Record to Information Resources compiled a list of resources of potential use at point of care. Resource details were drawn from product Web sites and organized by a metric used to evaluate medical point-of-care resources. Additional information was gathered from questions sent by e-mail and follow-up interviews with two practitioners, a hospital network, two software developers, and three publishers. Veterinarians with electronic records use a variety of information resources that are not linked to their software. Systems lack the infrastructure to use the Infobutton standard that has been gaining popularity in human EHRs. While some veterinary knowledge resources are digital, publisher sites and responses do not indicate a Web-based linkage of veterinary resources with EHRs. In order to facilitate lifelong learning and evidence-based practice, veterinarians and educators of future practitioners must demonstrate to veterinary practice software developers and publishers a clinically-based need to connect knowledge resources to veterinary EHRs.

  20. Improving access to information – defining core electronic resources for research and wellbeing

    Directory of Open Access Journals (Sweden)

    Kristiina Hormia-Poutanen

    2007-11-01

    Full Text Available Research and innovation are listed as the key success factors for the future development of Finnish prosperity and the Finnish economy. The Finnish libraries have developed a scenario to support this vision. University, polytechnic and research institute libraries as well as public libraries have defined the core electronic resources necessary to improve access to information in Finland. The primary aim of this work has been to provide information and justification for central funding for electronic resources to support the national goals. The secondary aim is to help with the reallocation of existing central funds to better support access to information.

  1. Cloning and characterization of the first polysaccharide lyase family 6 oligoalginate lyase from marine Shewanella sp. Kz7.

    Science.gov (United States)

    Li, Shangyong; Wang, Linna; Han, Feng; Gong, Qianhong; Yu, Wengong

    2016-01-01

    Alginate, the most abundant carbohydrate in brown macroalgae, is widely used in the food and pharmaceutical industries. Recently, alginate has attracted increasing attention, as it may serve as an alternative biomass for the production of biofuel. The degradation of alginate into monomeric units is the prerequisite for bioethanol production. All known oligoalginate lyases belong to the polysaccharide lyase (PL) family 7, 14, 15 and 17, and most of them preferred to degrade the polyM blocks to yield 4-deoxy-l-erythro-5-hexoseulose uronic acid as the primary product. In this study, we cloned an oligoalginate lyase gene, oalS6, from Shewanella sp. Kz7 and expressed it in Escherichia coli. The PL family 6 oligoalginate lyase (OalS6) has no significant sequence similarity with other known oligoalginate lyases. OalS6 contains a chondroitinase-like domain and was assigned to the PL family 6. This lyase is an exo-type oligoalginate lyase and prefer to depolymerize polyG block into 2, 4, 5, 6-tetrahydroxytetrahydro-2H-pyran-2-carboxylic acid. All of these results indicate that OalS6 is a novel oligoalginate lyase that is structurally and functionally different from other known oligoalginate lyases. This finding provides new insights into the development of biofuel processing biotechnologies from seaweed.

  2. Elektronik Bilgi Kaynaklarının Seçimi / Selection of Electronic Information Resources

    Directory of Open Access Journals (Sweden)

    Pınar Al

    2003-04-01

    Full Text Available For many years, library users have used only from the printed media in order to get the information that they have needed. Today with the widespread use of the Web and the addition of electronic information resources to library collections, the use of information in the electronic environment as well as in printed media is started to be used. In time, such types of information resources as, electronic journals, electronic books, electronic encyclopedias, electronic dictionaries and electronic theses have been added to library collections. In this study, selection criteria that can be used for electronic information resources are discussed and suggestions are provided for libraries that try to select electronic information resources for their collections.

  3. Using Electronic Information Resources Centers by Faculty Members at University Education: Competencies, Needs and Challenges

    Science.gov (United States)

    Abouelenein, Yousri

    2017-01-01

    This study aimed at investigating the factual situation of electronic information resources centers to faculty members at university education. Competencies that faculty members should possess regarding this issue were determined. Also their needs for (scientific research skills and teaching) were assessed. In addition, problems that hinder their…

  4. Localising versus standardising electronic human resource management: complexities and tensions between HRM and IT departments

    NARCIS (Netherlands)

    Tate, Mary; Furtmueller, E.; Wilderom, C.P.M.

    2013-01-01

    In this paper, we provide an analysis of the complexities involved during global e-HRM (Electronic Human Resource Management) implementation. We present findings from a case study on the challenge of global integration versus local responsiveness of e-HRM systems. We take a local site lens, analysin

  5. Use of Electronic Information Resources among Research Scholars in the Islamia University of Bahawalpur, Pakistan

    Science.gov (United States)

    Amjad, Anam; Ahmed, Shamshad; Bin Naeem, Salman

    2013-01-01

    This study examined the use of electronic resources among academic scholars of The Islamia University of Bahawalpur (IUB), Punjab, Pakistan. A quantitative survey was found most convenient and useful for this study. The total population of the study was 169 research students in IUB. The response rate was 79% and 133 utilizable responses were coded…

  6. The Acquisition and Management of Electronic Resources: Can Use Justify Cost?

    Science.gov (United States)

    Koehn, Shona L.; Hawamdeh, Suliman

    2010-01-01

    As library collections increasingly become digital, libraries are faced with many challenges regarding the acquisition and management of electronic resources. Some of these challenges include copyright and fair use, the first-sale doctrine, licensing versus ownership, digital preservation, long-term archiving, and, most important, the issue of…

  7. Purification, stabilization and characterization of tomato fatty acid hydroperoxide lyase

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Suurmeijer, C.N.S.P.; Pérez-Gilabert, M.; Unen, D.-J. van; Hijden, H.T.W.M. van der; Veldink, G.A.

    2000-01-01

    Fatty acid hydroperoxide lyase (HPO-lyase) was purified 300-fold from tomatoes. The enzymatic activity appeared to be very unstable, but addition of Triton X100 and beta-mercaptoethanol to the buffer yielded an active enzyme that could be stored for several months at −80°C. The enzyme was inhibited

  8. Characterization of pectate lyase A from Aspergillus niger

    NARCIS (Netherlands)

    Benen, J.A.E.; Parenicova, L.; Kester, H.C.M.; Visser, J.

    2001-01-01

    The Aspergillus niger plyA gene encoding pectate lyase A (EC 4.2.99.3) was cloned from a chromosomal EMBL4 library using the Aspergillus nidulans pectate lyase encoding gene [Dean, R. A., and Timberlake, W. E. (1989) Plant Cell 1, 275-284] as a probe. The plyA gene was overexpressed using a promoter

  9. Cysteine S-conjugate β-lyases

    OpenAIRE

    Arthur J. L. Cooper; Krasnikov, Boris F.; Pinto, John T.; Bruschi, Sam A.

    2010-01-01

    Cysteine S-conjugate β-lyases are pyridoxal 5′-phosphate (PLP)-containing enzymes that catalyze the conversion of cysteine S-conjugates [RSCH2CH(NH3+)CO2−] and selenium Se-conjugates [RSeCH2CH(NH3+)CO2−] that contain a leaving group in the β position to pyruvate, ammonium and a sulfur-containing fragment (RSH) or selenium-containing fragment (RSeH), respectively. At least ten PLP enzymes catalyze β-elimination reactions with such cysteine S-conjugates. All are enzymes involved in amino acid m...

  10. Direct Spectrophotometric Assay for Benzaldehyde Lyase Activity

    Directory of Open Access Journals (Sweden)

    Dessy Natalia

    2011-01-01

    Full Text Available Benzaldehyde lyase from Pseudomonas fluorescens Biovar I. (BAL, EC 4.1.2.38 is a versatile catalyst for the organic synthesis of chiral α-hydroxy ketones. To allow fast assessment of enzyme activity, a direct spectrophotometric assay is desirable. Here, a new robust and easy-to-handle assay based on UV absorption is presented. The assay developed is based on the ligation of the α-hydroxy ketone (R-2,2′-furoin from 2-furaldehyde. A robust assay with direct monitoring of the product is facilitated with a convenient concentration working range minimising experimental associated with low concentrations.

  11. 电子资源的编目策略%Cataloging Strategies of Electronic Resources

    Institute of Scientific and Technical Information of China (English)

    王亚林

    2012-01-01

    Compared with traditional paper resources, electronic resources have following characteristics which determine different cataloging strategies from paper resources. These characteristics are huge quantity, updating rapidly, coexistence of a variety of manifestations. The source data of electronic resources is usually provided by the database agent. The cataloging of electronic resources is based on the Chapter IX of Anglo-American Cataloging Rules, Library of Congress Rule Interpretations and rules of Cooperative Online Serials. There are two major cataloging methods for electronic resources abroad, they are single record approach and separate record approach. Peking University Library chooses the latter method and batches cataloging automatically using the source data.%电子资源吲传统纸质资源相比,具有数量大、更新快、多种载体表现并行等特点,且大部分出版机构能够提供数据源数据。这些特点决定了.电子资源应采取与纸质文献不同的编目策略。电子资源编日的主要依据是《英美编日条例》的第9章、美国《国会图书馆条例解释》及全美期刊合作编目计划的规定。对于电子资源的编目,国外有单一记录编目法和分散记录编目法。北京大学图书馆采用后者,同时利用数据源数据批舒自动编目。

  12. Power resource management and low-power remote wireless RF electronics

    Science.gov (United States)

    Jannson, Tomasz; Forrester, Thomas; Degrood, Kevin; Lee, Kang; Gans, Eric; Walter, Kevin

    2009-05-01

    Battery power resource management becomes a critical issue in the case of self-powered remote wireless RF electronics, where the basic parameter is time of system operation before battery recharging or battery replacement. In such cases, very often related to physical protection against antitampering (AT), proper theoretical modeling of a battery driven power supply in the context of a given digital electronic system is of utmost importance. Such modeling should include various types of batteries (primary and secondary), various self-discharge processes in different temperatures, and even energy harvesting, the latter to supply power for long-term content, low-power electronic subsystems. In this paper we analyze simple modeling of resource power management, including variations of all of these parameters and energy harvesting.

  13. Identifying and evaluating electronic learning resources for use in adult-gerontology nurse practitioner education.

    Science.gov (United States)

    Thompson, Hilaire J; Belza, Basia; Baker, Margaret; Christianson, Phyllis; Doorenbos, Ardith; Nguyen, Huong

    2014-01-01

    Enhancing existing curricula to meet newly published adult-gerontology advanced practice registered nurse (APRN) competencies in an efficient manner presents a challenge to nurse educators. Incorporating shared, published electronic learning resources (ELRs) in existing or new courses may be appropriate in order to assist students in achieving competencies. The purposes of this project were to (a) identify relevant available ELR for use in enhancing geriatric APRN education and (b) to evaluate the educational utility of identified ELRs based on established criteria. A multilevel search strategy was used. Two independent team members reviewed identified ELR against established criteria to ensure utility. Only resources meeting all criteria were retained. Resources were found for each of the competency areas and included formats such as podcasts, Web casts, case studies, and teaching videos. In many cases, resources were identified using supplemental strategies and not through traditional search or search of existing geriatric repositories. Resources identified have been useful to advanced practice educators in improving lecture and seminar content in a particular topic area and providing students and preceptors with additional self-learning resources. Addressing sustainability within geriatric APRN education is critical for sharing of best practices among educators and for sustainability of teaching and related resources. © 2014.

  14. Library Electronic Resource Sharing Among Liberal Arts Colleges: ACS Palladian Alliance Project

    Directory of Open Access Journals (Sweden)

    Wenxian Zhang

    1997-03-01

    Full Text Available 無Effective electronic resource sharing is critical to library information services of the 1990s. Explosion of data and increased cost of information force libraries to work together, and technological advancements present the library service profession a platform for resource sharing. The Palladian Alliance Project of the Associated Colleges of the South is designed to provides ACS member institutions an effective means to enhance information access for their faculty and students, and achieve significant cost containment in the years to come.

  15. Availability, Level of Use and Constraints to Use of Electronic Resources by Law Lecturers in Public Universities in Nigeria

    Science.gov (United States)

    Amusa, Oyintola Isiaka; Atinmo, Morayo

    2016-01-01

    (Purpose) This study surveyed the level of availability, use and constraints to use of electronic resources among law lecturers in Nigeria. (Methodology) Five hundred and fifty-two law lecturers were surveyed and four hundred and forty-two responded. (Results) Data analysis revealed that the level of availability of electronic resources for the…

  16. Purification and characterization of a novel alginate lyase from the marine bacterium Cobetia sp. NAP1 isolated from brown algae.

    Science.gov (United States)

    Yagi, Hisashi; Fujise, Asako; Itabashi, Narumi; Ohshiro, Takashi

    2016-12-01

    The application of marine resources, instead of fossil fuels, for biomass production is important for building a sustainable society. Seaweed is valuable as a source of marine biomass for producing biofuels such as ethanol, and can be used in various fields. Alginate is an anionic polysaccharide that forms the main component of brown algae. Various alginate lyases (e.g. exo- and endo-types and oligoalginate lyase) are generally used to degrade alginate. We herein describe a novel alginate lyase, AlgC-PL7, which belongs to the polysaccharide lyase 7 family. AlgC-PL7 was isolated from the halophilic Gram-negative bacterium Cobetia sp. NAP1 collected from the brown algae Padina arborescens Holmes. The optimal temperature and pH for AlgC-PL7 activity were 45 °C and 8, respectively. Additionally, AlgC-PL7 was thermostable and salt-tolerant, exhibited broad substrate specificity, and degraded alginate into monosaccharides. Therefore, AlgC-PL7 is a promising enzyme for the production of biofuels.

  17. Potential resource and toxicity impacts from metals in waste electronic devices.

    Science.gov (United States)

    Woo, Seung H; Lee, Dae Sung; Lim, Seong-Rin

    2016-04-01

    As a result of the continuous release of new electronic devices, existing electronic devices are quickly made obsolete and rapidly become electronic waste (e-waste). Because e-waste contains a variety of metals, information about those metals with the potential for substantial environmental impact should be provided to manufacturers, recyclers, and disposers to proactively reduce this impact. This study assesses the resource and toxicity (i.e., cancer, noncancer, and ecotoxicity) potentials of various heavy metals commonly found in e-waste from laptop computers, liquid-crystal display (LCD) monitors, LCD TVs, plasma TVs, color cathode ray tube (CRT) TVs, and cell phones and then evaluates such potentials using life cycle impact-based methods. Resource potentials derive primarily from Cu, Sb, Ag, and Pb. Toxicity potentials derive primarily from Pb, Ni, and Hg for cancer toxicity; from Pb, Hg, Zn, and As for noncancer toxicity; and from Cu, Pb, Hg, and Zn for ecotoxicity. Therefore, managing these heavy metals should be a high priority in the design, recycling, and disposal stages of electronic devices.

  18. Model of e-learning with electronic educational resources of new generation

    Directory of Open Access Journals (Sweden)

    A. V. Loban

    2017-01-01

    Full Text Available Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with electronic educational resource of new generation is developed, conditionally decomposed into three basic components: the formalization model of the course in the form of the thesaurusclassifier (“Author of e-resource”, the model of learning as management (“Coordination. Consultation. Control”, the learning model with the thesaurus-classifier (“Student”. Model “Author of e-resource” allows the student to achieve completeness, high degree of didactic elaboration and structuring of the studied material in triples of variants: modules of education information, practical task and control tasks; the result of the student’s (author’s of e-resource activity is the thesaurus-classifier. Model of learning as management is based on the principle of personal orientation of learning in computer environment and determines the logic of interaction between the lecturer and the student when determining the triple of variants individually for each student; organization of a dialogue between the lecturer and the student for consulting purposes; personal control of the student’s success (report generation and iterative search for the concept of the class assignment in the thesaurus-classifier before acquiring the required level of training. Model “Student” makes it possible to concretize the learning tasks in relation to the personality of the student and to the training level achieved; the assumption of the lecturer about the level of training of a

  19. Biochemical, Kinetic, and Spectroscopic Characterization of Ruegeria pomeroyi DddW--A Mononuclear Iron-Dependent DMSP Lyase.

    Directory of Open Access Journals (Sweden)

    Adam E Brummett

    Full Text Available The osmolyte dimethylsulfoniopropionate (DMSP is a key nutrient in marine environments and its catabolism by bacteria through enzymes known as DMSP lyases generates dimethylsulfide (DMS, a gas of importance in climate regulation, the sulfur cycle, and signaling to higher organisms. Despite the environmental significance of DMSP lyases, little is known about how they function at the mechanistic level. In this study we biochemically characterize DddW, a DMSP lyase from the model roseobacter Ruegeria pomeroyi DSS-3. DddW is a 16.9 kDa enzyme that contains a C-terminal cupin domain and liberates acrylate, a proton, and DMS from the DMSP substrate. Our studies show that as-purified DddW is a metalloenzyme, like the DddQ and DddP DMSP lyases, but contains an iron cofactor. The metal cofactor is essential for DddW DMSP lyase activity since addition of the metal chelator EDTA abolishes its enzymatic activity, as do substitution mutations of key metal-binding residues in the cupin motif (His81, His83, Glu87, and His121. Measurements of metal binding affinity and catalytic activity indicate that Fe(II is most likely the preferred catalytic metal ion with a nanomolar binding affinity. Stoichiometry studies suggest DddW requires one Fe(II per monomer. Electronic absorption and electron paramagnetic resonance (EPR studies show an interaction between NO and Fe(II-DddW, with NO binding to the EPR silent Fe(II site giving rise to an EPR active species (g = 4.29, 3.95, 2.00. The change in the rhombicity of the EPR signal is observed in the presence of DMSP, indicating that substrate binds to the iron site without displacing bound NO. This work provides insight into the mechanism of DMSP cleavage catalyzed by DddW.

  20. [Use of internet and electronic resources among Spanish intensivist physicians. First national survey].

    Science.gov (United States)

    Gómez-Tello, V; Latour-Pérez, J; Añón Elizalde, J M; Palencia-Herrejón, E; Díaz-Alersi, R; De Lucas-García, N

    2006-01-01

    Estimate knowledge and use habits of different electronic resources in a sample of Spanish intensivists: Internet, E-mail, distribution lists, and use of portable electronic devices. Self-applied questionnaire. A 50-question questionnaire was distributed among Spanish intensivists through the hospital marketing delegates of a pharmaceutical company and of electronic forums. A total of 682 questionnaires were analyzed (participation: 74%). Ninety six percent of those surveyed used Internet individually: 67% admitted training gap. Internet was the second source of clinical consultations most used (61%), slightly behind consultation to colleagues (65%). The pages consulted most were bibliographic databases (65%) and electronic professional journals (63%), with limited use of Evidence Based Medicine pages (19%). Ninety percent of those surveyed used e-mail regularly in the practice of their profession, although 25% admitted that were not aware of its possibilities. The use of E-mail decreased significantly with increase in age. A total of 62% of the intensivists used distribution lists. Of the rest, 42% were not aware of its existence and 32% admitted they had insufficient training to handle them. Twenty percent of those surveyed had portable electronic devices and 64% considered it useful, basically due to its rapid consultation at bedside. Female gender was a negative predictive factor of its use (OR 0.35; 95% CI 0.2-0.63; p=0.0002). A large majority of the Spanish intensivists use Internet and E-mail. E-mail lists and use of portable devices are still underused resources. There are important gaps in training and infrequent use of essential pages. There are specific groups that require directed educational policies.

  1. Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

    Science.gov (United States)

    Friege, Henning

    2012-09-01

    For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

  2. Cloning and characterization of the first polysaccharide lyase family 6 oligoalginate lyase from marine Shewanella sp. Kz7

    OpenAIRE

    Li, Shangyong; Wang, LinNa; Han, Feng; Gong, Qianhong; Yu, Wengong

    2015-01-01

    Alginate, the most abundant carbohydrate in brown macroalgae, is widely used in the food and pharmaceutical industries. Recently, alginate has attracted increasing attention, as it may serve as an alternative biomass for the production of biofuel. The degradation of alginate into monomeric units is the prerequisite for bioethanol production. All known oligoalginate lyases belong to the polysaccharide lyase (PL) family 7, 14, 15 and 17, and most of them preferred to degrade the polyM blocks to...

  3. Aufwand und Nutzen des Electronic Resource Management Systems RMS an der UB Kassel

    Directory of Open Access Journals (Sweden)

    Tobias Pohlmann

    2016-03-01

    The university library of Kassel therefore uses SemperTool’s web-based electronic resource management system RMS. This paper presents the functionality of this system and makes an estimate of the expenditure of work necessary to enter all relevant information about licensed databases, e-book and e-journal packages with the corresponding individual resources. It also describes existing and projected tools for analysis and evaluation, which are decisive for the usefulness of such a system, and concludes with the satisfaction reached at the university library of Kassel. These experiences may help other libraries to decide whether or not to introduce RMS or a comparable system.

  4. ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

    Directory of Open Access Journals (Sweden)

    Maria D. Tukalo

    2013-09-01

    Full Text Available This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions to enhance the creative potential of students in a modern learning environment.

  5. Teachers' Link to Electronic Resources in the Library Media Center: A Local Study of Awareness, Knowledge, and Influence

    Science.gov (United States)

    Williams, Teresa D.; Grimble, Bonnie J.; Irwin, Marilyn

    2004-01-01

    High school students often use online databases and the Internet in the school library media center (SLMC) to complete teachers' assignments. This case study used a survey to assess teachers' awareness of electronic resources, and to determine whether their directions influence student use of these resources in the SLMC. Participants were teachers…

  6. Impact of Knowledge Resources Linked to an Electronic Health Record on Frequency of Unnecessary Tests and Treatments

    Science.gov (United States)

    Goodman, Kenneth; Grad, Roland; Pluye, Pierre; Nowacki, Amy; Hickner, John

    2012-01-01

    Introduction: Electronic knowledge resources have the potential to rapidly provide answers to clinicians' questions. We sought to determine clinicians' reasons for searching these resources, the rate of finding relevant information, and the perceived clinical impact of the information they retrieved. Methods: We asked general internists, family…

  7. Reducing Clinical Trial Monitoring Resource Allocation and Costs Through Remote Access to Electronic Medical Records

    Science.gov (United States)

    Uren, Shannon C.; Kirkman, Mitchell B.; Dalton, Brad S.; Zalcberg, John R.

    2013-01-01

    Purpose: With electronic medical records (eMRs), the option now exists for clinical trial monitors to perform source data verification (SDV) remotely. We report on a feasibility study of remote access to eMRs for SDV and the potential advantages of such a process in terms of resource allocation and cost. Methods: The Clinical Trials Unit at the Peter MacCallum Cancer Centre, in collaboration with Novartis Pharmaceuticals Australia, conducted a 6-month feasibility study of remote SDV. A Novartis monitor was granted dedicated software and restricted remote access to the eMR portal of the cancer center, thereby providing an avenue through which perform SDV. Results: Six monitoring visits were conducted during the study period, four of which were performed remotely. The ability to conduct two thirds of the monitoring visits remotely in this complex phase III study resulted in an overall cost saving to Novartis. Similarly, remote monitoring eased the strain on internal resources, particularly monitoring space and hospital computer terminal access, at the cancer center. Conclusion: Remote access to patient eMRs for SDV is feasible and is potentially an avenue through which resources can be more efficiently used. Although this feasibility study involved limited numbers, there is no limit to scaling these processes to any number of patients enrolled onto large clinical trials. PMID:23633977

  8. Enhancing RGI lyase thermostability by targeted single point mutations

    DEFF Research Database (Denmark)

    Silva, Inês R.; Larsen, Dorte Møller; Jers, Carsten

    2013-01-01

    experimental verification of the thermal stability of the designed mutants versus the original wild-type RGI lyase, several promising single point mutations were obtained, particularly in position Glu434 on the surface of the enzyme protein. The best mutant, Glu434Leu, produced a half-life of 31 min at 60 °C......, corresponding to a 1.6-fold improvement of the thermal stability compared to the original RGI lyase. Gly55Val was the second best mutation with a thermostability half-life increase of 27 min at 60 °C, and the best mutations following were Glu434Trp, Glu434Phe, and Glu434Tyr, respectively. The data verify......Rhamnogalacturonan I lyase (RGI lyase) (EC 4.2.2.-) catalyzes the cleavage of rhamnogalacturonan I in pectins by β-elimination. In this study the thermal stability of a RGI lyase (PL 11) originating from Bacillus licheniformis DSM 13/ATCC14580 was increased by a targeted protein engineering...

  9. Electronic theses and dissertations: a review of this valuable resource for nurse scholars worldwide.

    Science.gov (United States)

    Goodfellow, L M

    2009-06-01

    A worldwide repository of electronic theses and dissertations (ETDs) could provide worldwide access to the most up-to-date research generated by masters and doctoral students. Until that international repository is established, it is possible to access some of these valuable knowledge resources. ETDs provide a technologically advanced medium with endless multimedia capabilities that far exceed the print and bound copies of theses and dissertations housed traditionally in individual university libraries. CURRENT USE: A growing trend exists for universities worldwide to require graduate students to submit theses or dissertations as electronic documents. However, nurse scholars underutilize ETDs, as evidenced by perusing bibliographic citation lists in many of the research journals. ETDs can be searched for and retrieved through several digital resources such as the Networked Digital Library of Theses and Dissertations (http://www.ndltd.org), ProQuest Dissertations and Theses (http://www.umi.com), the Australasian Digital Theses Program (http://adt.caul.edu.au/) and through individual university web sites and online catalogues. An international repository of ETDs benefits the community of nurse scholars in many ways. The ability to access recent graduate students' research electronically from anywhere in the world is advantageous. For scholars residing in developing countries, access to these ETDs may prove to be even more valuable. In some cases, ETDs are not available for worldwide access and can only be accessed through the university library from which the student graduated. Public access to university library ETD collections is not always permitted. Nurse scholars from both developing and developed countries could benefit from ETDs.

  10. A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources.

    Science.gov (United States)

    Oguchi, Masahiro; Murakami, Shinsuke; Sakanakura, Hirofumi; Kida, Akiko; Kameya, Takashi

    2011-01-01

    End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection methods were suggested for equipment types that currently have no specific collection systems in Japan, particularly for video games, notebook computers, and mid-size ICT and audio/video equipment.

  11. From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

    KAUST Repository

    Ramli, Rindra M.

    2017-05-17

    An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables and challenges as well as lessons learnt by the Project Team.

  12. A novel, inducible, citral lyase purified from spores of Penicillium digitatum

    NARCIS (Netherlands)

    Wolken, W.A.M.; Loo, W.J.V. van; Tramper, J.; Werf, M.J. van der

    2002-01-01

    A novel lyase, combining hydratase and aldolase activity, that converts citral into methylheptenone and acetaldehyde, was purified from spores of Penicillium digitatum. Remarkably, citral lyase activity was induced 118-fold by incubating nongerminating spores with the substrate, citral. This cofacto

  13. A novel, inducible, citral lyase purified from spores of Penicillium digitatum

    NARCIS (Netherlands)

    Wolken, W.A.M.; Loo, W.J.V. van; Tramper, J.; Werf, M.J. van der

    2002-01-01

    A novel lyase, combining hydratase and aldolase activity, that converts citral into methylheptenone and acetaldehyde, was purified from spores of Penicillium digitatum. Remarkably, citral lyase activity was induced 118-fold by incubating nongerminating spores with the substrate, citral. This

  14. Phycobilin:cystein-84 biliprotein lyase, a near-universal lyase for cysteine-84-binding sites in cyanobacterial phycobiliproteins.

    Science.gov (United States)

    Zhao, Kai-Hong; Su, Ping; Tu, Jun-Ming; Wang, Xing; Liu, Hui; Plöscher, Matthias; Eichacker, Lutz; Yang, Bei; Zhou, Ming; Scheer, Hugo

    2007-09-04

    Phycobilisomes, the light-harvesting complexes of cyanobacteria and red algae, contain two to four types of chromophores that are attached covalently to seven or more members of a family of homologous proteins, each carrying one to four binding sites. Chromophore binding to apoproteins is catalyzed by lyases, of which only few have been characterized in detail. The situation is complicated by nonenzymatic background binding to some apoproteins. Using a modular multiplasmidic expression-reconstitution assay in Escherichia coli with low background binding, phycobilin:cystein-84 biliprotein lyase (CpeS1) from Anabaena PCC7120, has been characterized as a nearly universal lyase for the cysteine-84-binding site that is conserved in all biliproteins. It catalyzes covalent attachment of phycocyanobilin to all allophycocyanin subunits and to cysteine-84 in the beta-subunits of C-phycocyanin and phycoerythrocyanin. Together with the known lyases, it can thereby account for chromophore binding to all binding sites of the phycobiliproteins of Anabaena PCC7120. Moreover, it catalyzes the attachment of phycoerythrobilin to cysteine-84 of both subunits of C-phycoerythrin. The only exceptions not served by CpeS1 among the cysteine-84 sites are the alpha-subunits from phycocyanin and phycoerythrocyanin, which, by sequence analyses, have been defined as members of a subclass that is served by the more specialized E/F type lyases.

  15. Electronic tracking of human resource skills and knowledge, just in time training, manageable due diligence

    Energy Technology Data Exchange (ETDEWEB)

    Kolodziej, M.A. [Quick Test International Inc., (Canada). Canadian Technology Human Resource Board; Baker, O. [KeySpan Energy Canada, Calgary, AB (Canada)

    2001-06-01

    KeySpan Energy Canada is in the process of obtaining recognition of various occupational profiles including pipeline operators, inspectors, and field and plant operators from various certifying organizations. The process of allowing individuals to obtain certification is recognized by Canadian Technology Human Resources Board as a step towards national standards for technologists and technicians. Proven competency is a must for workers in todays oil industry in response to increasingly stringent government safety regulations, environmental concerns and high public scrutiny. Quick Test international Inc. has developed a management tool in collaboration with end users at KeySpan Energy Canada. It is an electronic, Internet based competency tool for tracking personal competencies and maintaining continued competency. Response to the tool has been favourable. 2 refs., 4 figs.

  16. [HYGIENIC REGULATION OF THE USE OF ELECTRONIC EDUCATIONAL RESOURCES IN THE MODERN SCHOOL].

    Science.gov (United States)

    Stepanova, M I; Aleksandrova, I E; Sazanyuk, Z I; Voronova, B Z; Lashneva, L P; Shumkova, T V; Berezina, N O

    2015-01-01

    We studied the effect of academic studies with the use a notebook computer and interactive whiteboard on the functional state of an organism of schoolchildren. Using a complex of hygienic and physiological methods of the study we established that regulation of the computer activity of students must take into account not only duration but its intensity either. Design features of a notebook computer were shown both to impede keeping the optimal working posture in primary school children and increase the risk offormation of disorders of vision and musculoskeletal system. There were established the activating influence of the interactive whiteboard on performance activities and favorable dynamics of indices of the functional state of the organism of students under keeping optimal density of the academic study and the duration of its use. There are determined safety regulations of the work of schoolchildren with electronic resources in the educational process.

  17. Medical Image Resource Center--making electronic teaching files from PACS.

    Science.gov (United States)

    Lim, C C Tchoyoson; Yang, Guo Liang; Nowinski, Wieslaw L; Hui, Francis

    2003-12-01

    A picture archive and communications system (PACS) is a rich source of images and data suitable for creating electronic teaching files (ETF). However, the potential for PACS to support nonclinical applications has not been fully realized: at present there is no mechanism for PACS to identify and store teaching files; neither is there a standardized method for sharing such teaching images. The Medical Image Resource Center (MIRC) is a new central image repository that defines standards for data exchange among different centers. We developed an ETF server that retrieves digital imaging and communication in medicine (DICOM) images from PACS, and enables users to create teaching files that conform to the new MIRC schema. We test-populated our ETF server with illustrative images from the clinical case load of the National Neuroscience Institute, Singapore. Together, PACS and MIRC have the potential to benefit radiology teaching and research.

  18. Electronic Human Resource Management (e-HRM of Hotel Business in Phuket

    Directory of Open Access Journals (Sweden)

    Kitimaporn Choochote

    2015-04-01

    Full Text Available This research aims to study the pattern of the electronic human resources management (e-HRM of the hotel business in Phuket. The study is conducted with the implementation of field data and in-depth interview of hotels’ HR managers. In consequence, the study reveals that the hotel business has applied the use of the e-HRM varying in job recruitment (15 percent, employee engagement (55 percent, organizational file structure (10 percent, idea and creativity exchanges (38 percent and assessment system (6 percent. However, considered as 100 percent, the hotel business has not prepared to apply the use of the e-HRM in salary system, learning and training program, welfare allocation and career development.

  19. Quantitation of heparosan with heparin lyase III and spectrophotometry.

    Science.gov (United States)

    Huang, Haichan; Zhao, Yingying; Lv, Shencong; Zhong, Weihong; Zhang, Fuming; Linhardt, Robert J

    2014-02-15

    Heparosan is Escherichia coli K5 capsule polysaccharide, which is the key precursor for preparing bioengineered heparin. A rapid and effective quantitative method for detecting heparosan is important in the large-scale production of heparosan. Heparin lyase III (Hep III) effectively catalyzes the heparosan depolymerization, forming unsaturated disaccharides that are measurable using a spectrophotometer at 232 nm. We report a new method for the quantitative detection of heparosan with heparin lyase III and spectrophotometry that is safer and more specific than the traditional carbazole assay. In an optimized detection system, heparosan at a minimum concentration of 0.60 g/L in fermentation broth can be detected.

  20. Using mobile electronic devices to deliver educational resources in developing countries.

    Science.gov (United States)

    Mazal, Jonathan Robert; Ludwig, Rebecca

    2015-01-01

    Developing countries have far fewer trained radiography professionals than developed countries, which exacerbates the limited access to imaging services. The lack of trained radiographers reflects, in part, limited availability of radiographer-specific educational resources. Historically, organizations that provided such resources in the developing world faced challenges related to the limited stock of current materials as well as expenses associated with shipping and delivery. Four mobile electronic devices (MEDs) were loaded with educational content (e-books, PDFs, and digital applications) spanning major radiography topics. The MEDs were distributed to 4 imaging departments in Ghana, India, Nepal, and Nigeria based on evidence of need for radiography-specific resources, as revealed by survey responses. A cost comparison of postal delivery vs digital delivery of educational content was performed. The effectiveness of delivering additional content via Wi-Fi transmission also was evaluated. Feedback was solicited on users' experience with the MEDs as a delivery tool for educational content. An initial average per e-book expense of $30.05, which included the cost of the device, was calculated for the MED delivery method compared with $15.56 for postal delivery of printed materials. The cost of the MED delivery method was reduced to an average of $10.05 for subsequent e-book deliveries. Additional content was successfully delivered via Wi-Fi transmission to all recipients during the 3-month follow-up period. Overall user feedback on the experience was positive, and ideas for enhancing the MED-based method were identified. Using MEDs to deliver radiography-specific educational content appears to be more cost effective than postal delivery of printed materials on a long-term basis. MEDs are more efficient for providing updates to educational materials. Customization of content to department needs, and using projector devices could enhance the usefulness of MEDs for

  1. Molecular characterization of a Penicillium chrysogenum exo-rhamnogalacturonan lyase that is structurally distinct from other polysaccharide lyase family proteins.

    Science.gov (United States)

    Iwai, Marin; Kawakami, Takuya; Ikemoto, Takeshi; Fujiwara, Daisuke; Takenaka, Shigeo; Nakazawa, Masami; Ueda, Mitsuhiro; Sakamoto, Tatsuji

    2015-10-01

    We previously described an endo-acting rhamnogalacturonan (RG) lyase, termed PcRGL4A, of Penicillium chrysogenum 31B. Here, we describe a second RG lyase, called PcRGLX. We determined the cDNA sequence of the Pcrglx gene, which encodes PcRGLX. Based on analyses using a BLAST search and a conserved domain search, PcRGLX was found to be structurally distinct from known RG lyases and might belong to a new polysaccharide lyase family together with uncharacterized fungal proteins of Nectria haematococca, Aspergillus oryzae, and Fusarium oxysporum. The Pcrglx cDNA gene product (rPcRGLX) expressed in Escherichia coli demonstrated specific activity against RG but not against homogalacturonan. Divalent cations were not essential for the enzymatic activity of rPcRGLX. rPcRGLX mainly released unsaturated galacturonosyl rhamnose (ΔGR) from RG backbones used as the substrate from the initial stage of the reaction, indicating that the enzyme can be classified as an exo-acting RG lyase (EC 4.2.2.24). This is the first report of an RG lyase with this mode of action in Eukaryota. rPcRGLX acted synergistically with PcRGL4A to degrade soybean RG and released ΔGR. This ΔGR was partially decorated with galactose (Gal) residues, indicating that rPcRGLX preferred oligomeric RGs to polymeric RGs, that the enzyme did not require Gal decoration of RG backbones for degradation, and that the enzyme bypassed the Gal side chains of RG backbones. These characteristics of rPcRGLX might be useful in the determination of complex structures of pectins.

  2. Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

    Science.gov (United States)

    Rios, Pedro; Stuart, Julie Ann; Grant, Ed

    2003-12-01

    Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

  3. SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

    Directory of Open Access Journals (Sweden)

    Sheri L Lewis

    Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

  4. Isolation and characterization of an Antarctic Flavobacterium strain with agarase and alginate lyase activities

    Directory of Open Access Journals (Sweden)

    Lavín Paris

    2016-09-01

    Full Text Available Several bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta, in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17ºC and maximum temperature (20°C of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C, agarose (50°C and alginate (30°C during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.

  5. Priming ammonia lyases and aminomutases for industrial and therapeutic applications

    NARCIS (Netherlands)

    Heberling, Matthew M.; Wu, Bian; Bartsch, Sebastian; Janssen, Dick B.

    2013-01-01

    Ammonia lyases (AL) and aminomutases (AM) are emerging in green synthetic routes to chiral amines and an AL is being explored as an enzyme therapeutic for treating phenylketonuria and cancer. Although the restricted substrate range of the wild-type enzymes limits their widespread application, the no

  6. Redesign of a Phenylalanine Aminomutase into a Phenylalanine Ammonia Lyase

    NARCIS (Netherlands)

    Bartsch, S.; Wybenga, G.G.; Jansen, M.; Heberling, M.M.; Wu, B.; Dijkstra, B.W.; Janssen, D.B.

    2013-01-01

    An aminomutase, naturally catalyzing the interconversion of (S)--phenylalanine and (R)--phenylalanine, was converted into an ammonia lyase catalyzing the nonoxidative deamination of phenylalanine to cinnamic acid by a rational single-point mutation. It could be shown by crystal structures and kineti

  7. Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

    Science.gov (United States)

    Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

    2015-01-01

    The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

  8. Utilization of Electronic Information Resources by Undergraduate Students of University of Ibadan: A Case Study of Social Sciences and Education

    Science.gov (United States)

    Owolabi, Sola; Idowu, Oluwafemi A.; Okocha, Foluke; Ogundare, Atinuke Omotayo

    2016-01-01

    The study evaluated utilization of electronic information resources by undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan. The study adopted a descriptive survey design with a study population of 1872 undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan, from which a…

  9. Human resource requirements for quality-assured electronic data capture of the tuberculosis case register

    Directory of Open Access Journals (Sweden)

    Hoa Nguyen B

    2012-01-01

    Full Text Available Abstract Background The tuberculosis case register is the data source for the reports submitted by basic management units to the national tuberculosis program. Our objective was to measure the data entry time required to complete and double-enter one record, and to estimate the time for the correction of errors in the captured information from tuberculosis case registers in Cambodia and Viet Nam. This should assist in quantifying the additional requirements in human resources for national programs moving towards electronic recording and reporting. Methods Data from a representative sample of tuberculosis case registers from Cambodia and Viet Nam were double-entered and discordances resolved by rechecking the original case register. Computer-generated data entry time recorded the time elapsed between opening of a new record and saving it to disk. Results The dataset comprised 22,732 double-entered records of 11,366 patients (37.1% from Cambodia and 62.9% from Viet Nam. The mean data entry times per record were 97.5 (95% CI: 96.2-98.8 and 66.2 (95% CI: 59.5-73.0 seconds with medians of 90 and 31 s respectively in Cambodia and in Viet Nam. The percentage of records with an error was 6.0% and 39.0% respectively in Cambodia and Viet Nam. Data entry time was inversely associated with error frequency. We estimate that approximately 118-person-hours were required to produce 1,000 validated records. Conclusions This study quantifies differences between two countries for data entry time for the tuberculosis case register and frequencies of data entry errors and suggests that higher data entry speed is partially offset by requiring revisiting more records for corrections.

  10. Isolation of Protoplasts from Undaria pinnatifida by Alginate Lyase Digestion

    Institute of Scientific and Technical Information of China (English)

    HU Xiaoke; JIANG Xiaolu; GUAN Huashi

    2003-01-01

    The aim of this study is to isolate protoplasts from Undaria pinnatifida. Protoplasts of the alga were isolated enzymatically by using alginate lyase, which was prepared by fermenting culture of a strain Vibrio sp. 510. Monofacterial method was applied for optimizing digestion condition. The optimum condition for protoplast preparation is enzymatic digestion at 28 ℃ for 2 h using alginate lyase at the concentration of 213.36 U (8 mL) every 0.5 g fresh thalline with NaCl 50 and at the shaking speed of 150 r min-1 during digestion. The protoplast yield can reach 2.62 + 0.09 million per 0.5 g fresh leave under the optimum condition. The enzyme activity is inhibited by Ca2+ and slightly enhanced by Fe2+ and Mn2+ at concentrations of 0.05, 0.08 and 0.10 molL-1.

  11. Use and Cost of Electronic Resources in Central Library of Ferdowsi University Based on E-metrics

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Davarpanah

    2012-07-01

    Full Text Available The purpose of this study was to investigate the usage of electronic journals in Ferdowsi University, Iran based on e-metrics. The paper also aimed to emphasize the analysis of cost-benefit and the correlation between the journal impact factors and the usage data. In this study experiences of Ferdowsi University library on licensing and usage of electronic resources was evaluated by providing a cost-benefit analysis based on the cost and usage statistics of electronic resources. Vendor-provided data were also compared with local usage data. The usage data were collected by tracking web-based access locally, and by collecting vender-provided usage data. The data sources were one-year of vendor-supplied e-resource usage data such as Ebsco, Elsevier, Proquest, Emerald, Oxford and Springer and local usage data collected from the Ferdowsi university web server. The study found that actual usage values differ for vendor-provided data and local usage data. Elsevier has got the highest usage degree in searches, sessions and downloads. Statistics also showed that a small number of journals satisfy significant amount of use while the majority of journals were used less frequent and some were never used at all. The users preferred the PDF rather than HTML format. The data in subject profile suggested that the provided e-resources were best suited to certain subjects. There was no correlation between IF and electronic journal use. Monitoring the usage of e-resources gained increasing importance for acquisition policy and budget decisions. The article provided information about local metrics for the six surveyed vendors/publishers, e.g. usage trends, requests per package, cost per use as related to the scientific specialty of the university.

  12. Refeeding syndrome in a young woman with argininosuccinate lyase deficiency

    Directory of Open Access Journals (Sweden)

    M. Stuy

    2015-09-01

    Full Text Available A severely chronically protein and calorie restricted young woman with argininosuccinate lyase deficiency developed transient refeeding syndrome (RFS and hyperammonemia after modest diet liberalization following initiation of glycerol phenylbutyrate (GPB. The patient required IV supportive care and supplementation with potassium, magnesium and calcium. She is now doing well on GPB and an appropriate maintenance diet. Susceptibility to RFS should be considered in chronically nutritionally restricted patients with metabolic disorders after liberalization of diet.

  13. Refeeding syndrome in a young woman with argininosuccinate lyase deficiency.

    Science.gov (United States)

    Stuy, M; Chen, G-F; Masonek, J M; Scharschmidt, B F

    2015-09-01

    A severely chronically protein and calorie restricted young woman with argininosuccinate lyase deficiency developed transient refeeding syndrome (RFS) and hyperammonemia after modest diet liberalization following initiation of glycerol phenylbutyrate (GPB). The patient required IV supportive care and supplementation with potassium, magnesium and calcium. She is now doing well on GPB and an appropriate maintenance diet. Susceptibility to RFS should be considered in chronically nutritionally restricted patients with metabolic disorders after liberalization of diet.

  14. Refeeding syndrome in a young woman with argininosuccinate lyase deficiency☆

    Science.gov (United States)

    Stuy, M.; Chen, G.-F.; Masonek, J.M.; Scharschmidt, B.F.

    2015-01-01

    A severely chronically protein and calorie restricted young woman with argininosuccinate lyase deficiency developed transient refeeding syndrome (RFS) and hyperammonemia after modest diet liberalization following initiation of glycerol phenylbutyrate (GPB). The patient required IV supportive care and supplementation with potassium, magnesium and calcium. She is now doing well on GPB and an appropriate maintenance diet. Susceptibility to RFS should be considered in chronically nutritionally restricted patients with metabolic disorders after liberalization of diet. PMID:26937403

  15. Bioscouring Knitted Cotton Fabric with an Experimental Pectate Lyase

    Institute of Scientific and Technical Information of China (English)

    D K Appiah; MAO Zhi-ping; L(U) Jia-hua

    2007-01-01

    An experimental pectate lyase enzyme was used toscour knitted cotton fabric and the emphasis was on pectinremoval. Using an enzyme dosage of 0.2 g/L at temperature55℃ and pH 6.35 for 30 rain, good scouring properties wereobtained. When appropriate concentrations of 1 - HydroxyEthylidene- 1, 1 - Diphosphonic Acid(HEDP) and CaCl2were added, the percentage pectin removal improvedsignificantly.

  16. Comparative characterization of three bacterial exo-type alginate lyases.

    Science.gov (United States)

    Hirayama, Makoto; Hashimoto, Wataru; Murata, Kousaku; Kawai, Shigeyuki

    2016-05-01

    Alginate, a major acidic polysaccharide in brown macroalgae, has attracted attention as a carbon source for production of ethanol and other chemical compounds. Alginate is monomerized by exo-type alginate lyase into an unsaturated uronate; thus, this enzyme is critical for the saccharification and utilization of alginate. Although several exo-type alginate lyases have been characterized independently, their activities were not assayed under the same conditions or using the same unit definition, making it difficult to compare enzymatic properties or to select the most suitable enzyme for saccharification of alginate. In this study, we characterized the three bacterial exo-type alginate lyases under the same conditions: A1-IV of Sphingomonas sp. strain A1, Atu3025 of Agrobacterium tumefaciens, and Alg17c of Saccharophagus degradans. A1-IV had the highest specific activity as well as the highest productivity of uronate, whereas Alg17c had the lowest activity and productivity. Only dialyzed Atu3025 and Alg17c were tolerant to freezing. Alg17c exhibited a remarkable halotolerance, which may be advantageous for monomerization of alginate from marine brown algae. Thus, each enzyme exhibited particular desirable and undesirable properties. Our results should facilitate further utilization of the promising polysaccharide alginate. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Inactivating effects of the lactoperoxidase system on bacterial lyases involved in oral malodour production.

    Science.gov (United States)

    Nakano, Manabu; Shin, Kouichirou; Wakabayashi, Hiroyuki; Yamauchi, Koji; Abe, Fumiaki; Hironaka, Shouji

    2015-10-01

    The main components of oral malodour have been identified as volatile sulfur compounds (VSCs), including hydrogen sulfide (H(2)S) and methyl mercaptan (CH(3)SH). The lactoperoxidase (LPO) system (consisting of LPO, glucose oxidase, glucose and thiocyanate) was previously shown to exhibit antimicrobial activities against some oral bacteria in vitro and suppressive effects on VSCs in mouth air in a clinical trial. Here, we examined the in vitro effects of the LPO system on the activities of the bacterial lyases involved in the production of VSCs by oral anaerobes. The exposure of crude bacterial extracts of Fusobacterium nucleatum and Porphyromonas gingivalis or purified methionine γ-lyase to the LPO system resulted in the inactivation of their lyase activities through l-cysteine and l-methionine, which was linked to the production of H(2)S and CH(3)SH, respectively. The exposure of living F. nucleatum and P. gingivalis cells to the LPO system resulted in the suppression of cell numbers and lyase activities. The inactivation of the crude bacterial extracts of F. nucleatum and purified methionine γ-lyase by the LPO system was partly recovered by the addition of DTT. Therefore, the LPO system may inactivate bacterial lyases including methionine γ-lyase by reacting with the free cysteine residues of lyases. These results suggested that the LPO system suppresses the production of VSCs not only through its antimicrobial effects, but also by its inactivating effects on the bacterial lyases of F. nucleatum and P. gingivalis.

  18. Use and User Perception of Electronic Information Resources: A Case Study of Siva Institute of Frontier Technology, India

    Directory of Open Access Journals (Sweden)

    Velmurugan Chandran

    2013-12-01

    Full Text Available The present study aims to explore the use and user perception of electronic resources in Siva Institute of Frontier Technology, India. A total number of 123 users were taken into account for the study through a questionnaire-based survey method. A well-structured questionnaire was designed and distributed to the selected 200 students and staff members. 123 copies of the questionnaires were returned dully filled in and the overall response rate was 61.50 percent. The questionnaire contained both open- and close-ended questions. The collected data were classified, analyzed, and tabulated by using simple statistical methods. This study covers the impact of electronic resources on students and faculty in their academic pursuit.

  19. How Human Resource Professionals Use Electronic Channels to Communicate CSR : A case study focused on Solvay's French industrial sites

    OpenAIRE

    Fournet, Clara; Pauly, Marissa

    2015-01-01

    Corporate Social Responsibility (CSR) has become a large concern for many companies with the rise of globalization. Oftentimes, companies are encouraged to communicate CSR externally, but not internally. This research focuses upon the internal communication of CSR, specifically how Human Resource (HR) professionals use electronic channels to communicate to employees. The scope of this research is focused solely upon HR professionals within Solvay’s French industrial sites, which produce chemi...

  20. Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

    Directory of Open Access Journals (Sweden)

    Soto Giselle

    2008-11-01

    Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

  1. Tracking the Flow of Resources in Electronic Waste - The Case of End-of-Life Computer Hard Disk Drives.

    Science.gov (United States)

    Habib, Komal; Parajuly, Keshav; Wenzel, Henrik

    2015-10-20

    Recovery of resources, in particular, metals, from waste flows is widely seen as a prioritized option to reduce their potential supply constraints in the future. The current waste electrical and electronic equipment (WEEE) treatment system is more focused on bulk metals, where the recycling rate of specialty metals, such as rare earths, is negligible compared to their increasing use in modern products, such as electronics. This study investigates the challenges in recovering these resources in the existing WEEE treatment system. It is illustrated by following the material flows of resources in a conventional WEEE treatment plant in Denmark. Computer hard disk drives (HDDs) containing neodymium-iron-boron (NdFeB) magnets were selected as the case product for this experiment. The resulting output fractions were tracked until their final treatment in order to estimate the recovery potential of rare earth elements (REEs) and other resources contained in HDDs. The results further show that out of the 244 kg of HDDs treated, 212 kg comprising mainly of aluminum and steel can be finally recovered from the metallurgic process. The results further demonstrate the complete loss of REEs in the existing shredding-based WEEE treatment processes. Dismantling and separate processing of NdFeB magnets from their end-use products can be a more preferred option over shredding. However, it remains a technological and logistic challenge for the existing system.

  2. The impact of electronic healthcare associated infection surveillance software on infection prevention resources: A systematic review of the literature.

    Science.gov (United States)

    Russo, Philip L; Shaban, Ramon Z; MacBeth, Deborough; Carter, Abigail; Mitchell, Brett G

    2017-09-08

    Surveillance of healthcare-associated infections is fundamental for infection prevention. The methods and practices for surveillance have evolved as technology becomes more advanced. The availability of electronic surveillance software (ESS) has increased, and yet adoption of ESS is slow. It is argued that ESS deliver savings through automation, particularly in terms of human resourcing and infection prevention (IP) staff time. This paper describes the findings of a systematic review on the impact of ESS on IP resources. A systematic search was conducted of electronic databases Medline and the Cumulative Index to Nursing and Allied Health Literature published between 1st January 2006 and 31(st) December 2016 with analysis using Newcastle-Ottawa Scale. 2832 articles were reviewed of which 16 studies met the inclusion criteria. IP resources were identified as time undertaken on surveillance. A reduction in IP staff time to undertake surveillance was demonstrated in 13 studies. The reduction proportion ranged from 12.5% - 98.4% (mean 73.9%). The remaining three did not allow for any estimation of the effect in terms of IP staff time. None of the studies demonstrated an increase in IP staff time. The results of this review demonstrate that adopting ESS yield considerable dividends in IP staff time relating to data collection and case ascertainment whilst maintaining high levels of sensitivity and specificity. This has the potential to enable reinvestment into other components of IP to maximise efficient use of scare IP resources. Copyright © 2017. Published by Elsevier Ltd.

  3. HELP (INFORMATION ELECTRONIC RESOURCE "CHRONICLE OF ONU: DATES, FACTS, EVENTS": HISTORY OF UNIVERSITY IN INFORMATION SPACE

    Directory of Open Access Journals (Sweden)

    А. М. Гавриленко

    2016-03-01

    Object of research is the help information resource "The chronicle of the Odessa national university of I. I. Mechnikov: dates, facts, events". The main objective of our article – to state the main methodological bases of creation of information resource. One of advantages of information resource is possibility of continuous updating and replenishment by new information. Main objective of creation of this information resource is systematization of material on stories of the Odessa national university of I. I. Mechnikov from the date of his basis to the present, ensuring interactive access to information on the main dates, the most significant events in life of university. The base of research are sources on the history of university, chronology of historical development, formation of infrastructure, cadres and scientific researches. In information resource the main stages of development, functioning and transformation of the Odessa University are analyzed, information on its divisions is collected. For creation of this information resource in Scientific library the method of work was developed, the main selection criteria of data are allocated. This information resource have practical value for all who is interested in history of university, historians, scientists-researchers of history of science and the city of Odessa.

  4. Effect of Access to an Electronic Medical Resource on Performance Characteristics of a Certification Examination: A Randomized Controlled Trial.

    Science.gov (United States)

    Lipner, Rebecca S; Brossman, Bradley G; Samonte, Kelli M; Durning, Steven J

    2017-09-05

    Electronic resources are increasingly used in medical practice. Their use during high-stakes certification examinations has been advocated by many experts, but whether doing so would affect the capacity to differentiate between high and low abilities is unknown. To determine the effect of electronic resources on examination performance characteristics. Randomized controlled trial. Medical certification program. 825 physicians initially certified by the American Board of Internal Medicine (ABIM) who passed the Internal Medicine Certification examination or sat for the Internal Medicine Maintenance of Certification (IM-MOC) examination in 2012 to 2015. Participants were randomly assigned to 1 of 4 conditions: closed book using typical or additional time, or open book (that is, UpToDate [Wolters Kluwer]) using typical or additional time. All participants took the same modified version of the IM-MOC examination. Primary outcomes included item difficulty (how easy or difficult the question was), item discrimination (how well the question differentiated between high and low abilities), and average question response time. Secondary outcomes included examination dimensionality (that is, the number of factors measured) and test-taking strategy. Item response theory was used to calculate question characteristics. Analysis of variance compared differences among conditions. Closed-book conditions took significantly less time than open-book conditions (mean, 79.2 seconds [95% CI, 78.5 to 79.9 seconds] vs. 110.3 seconds [CI, 109.2 to 111.4 seconds] per question). Mean discrimination was statistically significantly higher for open-book conditions (0.34 [CI, 0.32 to 0.35] vs. 0.39 [CI, 0.37 to 0.41] per question). A strong single dimension showed that the examination measured the same factor with or without the resource. Only 1 electronic resource was evaluated. Inclusion of an electronic resource with time constraints did not adversely affect test performance and did not change

  5. Understanding intention to use electronic information resources: A theoretical extension of the technology acceptance model (TAM).

    Science.gov (United States)

    Tao, Donghua

    2008-11-06

    This study extended the Technology Acceptance Model (TAM) by examining the roles of two aspects of e-resource characteristics, namely, information quality and system quality, in predicting public health students' intention to use e-resources for completing research paper assignments. Both focus groups and a questionnaire were used to collect data. Descriptive analysis, data screening, and Structural Equation Modeling (SEM) techniques were used for data analysis. The study found that perceived usefulness played a major role in determining students' intention to use e-resources. Perceived usefulness and perceived ease of use fully mediated the impact that information quality and system quality had on behavior intention. The research model enriches the existing technology acceptance literature by extending TAM. Representing two aspects of e-resource characteristics provides greater explanatory information for diagnosing problems of system design, development, and implementation.

  6. Building and Managing Electronic Resources in Digital Era in India with Special Reference to IUCAA and NIV, Pune: A Comparative Case Study

    Science.gov (United States)

    Sahu, H. K.; Singh, S. N.

    2015-04-01

    This paper discusses and presents a comparative case study of two libraries in Pune, India, Inter-University Centre for Astronomy and Astrophysics and Information Centre and Library of National Institute of Virology (Indian Council of Medical Research). It compares how both libraries have managed their e-resource collections, including acquisitions, subscriptions, and consortia arrangements, while also developing a collection of their own resources, including pre-prints and publications, video lectures, and other materials in an institutional repository. This study illustrates how difficult it is to manage electronic resources in a developing country like India, even though electronic resources are used more than print resources. Electronic resource management can be daunting, but with a systematic approach, various problems can be solved, and use of the materials will be enhanced.

  7. Print and Electronic Resources: Usage Statistics at Guru Gobind Singh Indraprastha University Library

    Science.gov (United States)

    Kapoor, Kanta

    2010-01-01

    Purpose: The purpose of this paper is to quantify the use of electronic journals in comparison with the print collections in the Guru Gobind Singh Indraprastha University Library. Design/methodology/approach: A detailed analysis was made of the use of lending services, the Xerox facility and usage of electronic journals such as Science Direct,…

  8. Print and Electronic Resources: Usage Statistics at Guru Gobind Singh Indraprastha University Library

    Science.gov (United States)

    Kapoor, Kanta

    2010-01-01

    Purpose: The purpose of this paper is to quantify the use of electronic journals in comparison with the print collections in the Guru Gobind Singh Indraprastha University Library. Design/methodology/approach: A detailed analysis was made of the use of lending services, the Xerox facility and usage of electronic journals such as Science Direct,…

  9. Structure and mechanism of the phycobiliprotein lyase CpcT.

    Science.gov (United States)

    Zhou, Wei; Ding, Wen-Long; Zeng, Xiao-Li; Dong, Liang-Liang; Zhao, Bin; Zhou, Ming; Scheer, Hugo; Zhao, Kai-Hong; Yang, Xiaojing

    2014-09-26

    Pigmentation of light-harvesting phycobiliproteins of cyanobacteria requires covalent attachment of open-chain tetrapyrroles, bilins, to the apoproteins. Thioether formation via addition of a cysteine residue to the 3-ethylidene substituent of bilins is mediated by lyases. T-type lyases are responsible for attachment to Cys-155 of phycobiliprotein β-subunits. We present crystal structures of CpcT (All5339) from Nostoc (Anabaena) sp. PCC 7120 and its complex with phycocyanobilin at 1.95 and 2.50 Å resolution, respectively. CpcT forms a dimer and adopts a calyx-shaped β-barrel fold. Although the overall structure of CpcT is largely retained upon chromophore binding, arginine residues at the opening of the binding pocket undergo major rotameric rearrangements anchoring the propionate groups of phycocyanobilin. Based on the structure and mutational analysis, a reaction mechanism is proposed that accounts for chromophore stabilization and regio- and stereospecificity of the addition reaction. At the dimer interface, a loop extending from one subunit partially shields the opening of the phycocyanobilin binding pocket in the other subunit. Deletion of the loop or disruptions of the dimer interface significantly reduce CpcT lyase activity, suggesting functional relevance of the dimer. Dimerization is further enhanced by chromophore binding. The chromophore is largely buried in the dimer, but in the monomer, the 3-ethylidene group is accessible for the apophycobiliprotein, preferentially from the chromophore α-side. Asp-163 and Tyr-65 at the β- and α-face near the E-configured ethylidene group, respectively, support the acid-catalyzed nucleophilic Michael addition of cysteine 155 of the apoprotein to an N-acylimmonium intermediate proposed by Grubmayr and Wagner (Grubmayr, K., and Wagner, U. G. (1988) Monatsh. Chem. 119, 965-983).

  10. Alfalfa contains substantial 9-hydroperoxide lyase activity and a 3Z:2E-enal isomerase

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.

    1999-01-01

    Fatty acid hydroperoxides formed by lipoxygenase can be cleaved by hydroperoxide lyase resulting in the formation of short-chain aldehydes and omega-oxo acids. Plant hydroperoxide lyases use 13- or 9-hydroperoxy linoleic and linolenic acid as substrates. Alfalfa (Medicago sativa L.) has been reporte

  11. Role of phosphoenolpyruvate in the NADP-isocitrate dehydrogenase and isocitrate lyase reaction in Escherichia coli.

    Science.gov (United States)

    Ogawa, Tadashi; Murakami, Keiko; Mori, Hirotada; Ishii, Nobuyoshi; Tomita, Masaru; Yoshin, Masataka

    2007-02-01

    Phosphoenolpyruvate inhibited Escherichia coli NADP-isocitrate dehydrogenase allosterically (Ki of 0.31 mM) and isocitrate lyase uncompetitively (Ki' of 0.893 mM). Phosphoenolpyruvate enhances the uncompetitive inhibition of isocitrate lyase by increasing isocitrate, which protects isocitrate dehydrogenase from the inhibition, and contributes to the control through the tricarboxylic acid cycle and glyoxylate shunt.

  12. Role of Phosphoenolpyruvate in the NADP-Isocitrate Dehydrogenase and Isocitrate Lyase Reaction in Escherichia coli▿

    OpenAIRE

    2006-01-01

    Phosphoenolpyruvate inhibited Escherichia coli NADP-isocitrate dehydrogenase allosterically (Ki of 0.31 mM) and isocitrate lyase uncompetitively (Ki′ of 0.893 mM). Phosphoenolpyruvate enhances the uncompetitive inhibition of isocitrate lyase by increasing isocitrate, which protects isocitrate dehydrogenase from the inhibition, and contributes to the control through the tricarboxylic acid cycle and glyoxylate shunt.

  13. Possible role of cysteine-S-conjugate β-lyase in species differences in cisplatin nephrotoxicity.

    Science.gov (United States)

    Katayama, Rieko; Nagata, Saori; Iida, Hiroko; Yamagishi, Norio; Yamashita, Tetsuro; Furuhama, Kazuhisa

    2011-09-01

    To better understand species differences in cisplatin nephrotoxicity, we focused on renal cysteine-S-conjugate β-lyase (C-S lyase), which may play a crucial role in the metabolism of platinum (Pt)-cysteine conjugates. Aminooxyacetic acid hemihydrochloride (AOAA), an inhibitor of C-S lyase, reduced renal injuries due to cisplatin in rats, suggesting involvement of C-S lyase. On day 5 following a bolus cisplatin injection, three species showed in vivo nephrotoxic potentials in the order of rats>mice=rabbits (the highest to lowest), based on body surface. The levels of renal Pt residue at the nephrotoxic dose were in order of rabbits>rats>mice. Meanwhile, the activity of endogenous (basal) mitochondrial aspartate aminotransferase (AST), one of the C-S lyases, in the renal cortex of naive animals was rats>mice=rabbits. In a qualitative Western blot analysis, expression of mitochondrial C-S lyase in the kidney was observed at approximately 37kDa in all five species used. In in vitro studies, the cytotoxicity of cisplatin was dependent on the expression level of C-S lyase mRNA in the respective renal cells. These results demonstrate that species differences in cisplatin nephrotoxicity are attributable to an interaction of renal Pt transition with C-S lyase activity.

  14. Alfalfa contains substantial 9-hydroperoxide lyase activity and a 3Z:2E-enal isomerase

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.

    1999-01-01

    Fatty acid hydroperoxides formed by lipoxygenase can be cleaved by hydroperoxide lyase resulting in the formation of short-chain aldehydes and omega-oxo acids. Plant hydroperoxide lyases use 13- or 9-hydroperoxy linoleic and linolenic acid as substrates. Alfalfa (Medicago sativa L.) has been

  15. Structure and Mechanism of PhnP, a Phosphodiesterase of the Carbon-Phosphorus Lyase Pathway

    DEFF Research Database (Denmark)

    He, Shu-Mei; Wathier, Matthew; Podzelinska, Kateryna;

    2011-01-01

    PhnP is a phosphodiesterase that plays an important role within the bacterial carbon-phosphorus lyase (CP-lyase) pathway by recycling a "dead-end" intermediate, 5-phospho-α-d-ribosyl 1,2-cyclic phosphate, that is formed during organophosphonate catabolism. As a member of the metallo-β-lactamase s...

  16. A novel gene encoding xanthan lyase of Paenibacillus alginolyticus strain XL-1

    NARCIS (Netherlands)

    Ruijssenaars, H.J.; Hartmans, S.; Verdoes, J.C.

    2000-01-01

    Xanthan-modifying enzymes are powerful tools in studying structure-function relationships of this polysaccharide. One of these modifying enzymes is xanthan lyase, which removes the terminal side chain residue of xanthan. In this paper, the cloning and sequencing of the first xanthan lyase-encoding g

  17. Alfalfa contains substantial 9-hydroperoxide lyase activity and a 3Z:2E-enal isomerase

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.

    1999-01-01

    Fatty acid hydroperoxides formed by lipoxygenase can be cleaved by hydroperoxide lyase resulting in the formation of short-chain aldehydes and omega-oxo acids. Plant hydroperoxide lyases use 13- or 9-hydroperoxy linoleic and linolenic acid as substrates. Alfalfa (Medicago sativa L.) has been reporte

  18. Intention to use and actual use of electronic information resources: further exploring Technology Acceptance Model (TAM).

    Science.gov (United States)

    Tao, Donghua

    2009-11-14

    Following up a previous study that examined public health students' intention to use e-resources for completing research paper assignments, the present study proposed two models to investigate whether or not public health students actually used the e-resources they intended to use and whether or not the determinants of intention to use predict actual use of e-resources. Focus groups and pre- and post-questionnaires were used to collect data. Descriptive analysis, data screening, and Structural Equation Modeling (SEM) techniques were used for data analysis. The study found that the determinants of intention-to-use significantly predict actual use behavior. Direct impact of perceived usefulness and indirect impact of perceived ease of use to both behavior intention and actual behavior indicated the importance of ease of use at the early stage of technology acceptance. Non-significant intention-behavior relationship prompted thoughts on the measurement of actual behavior and multidimensional characteristics of the intention construct.

  19. Hydroxynitrile Lyases: Biological Sources and Application as Biocatalysts

    Directory of Open Access Journals (Sweden)

    Herfried Griengl

    2004-01-01

    Full Text Available We review the state of the art regarding the application of hydroxynitrile lyases to obtain, enantioselectively, (R- and (S-cyanohydrins of aldehydes and ketones. Special emphasis is given to recent preparative applications and to research for extending the number of plants serving as sources for the enzyme. Depending on the plant family, the mechanism of the enzyme-catalysed reaction can be different. A novel area of research is the consideration of evolutionary aspects on the basis of structure comparisons.

  20. Alginate lyase: Review of major sources and classification, properties, structure-function analysis and applications

    Science.gov (United States)

    Zhu, Benwei; Yin, Heng

    2015-01-01

    Alginate lyases catalyze the degradation of alginate, a complex copolymer of α-L-guluronate and its C5 epimer β-D-mannuronate. The enzymes have been isolated from various kinds of organisms with different substrate specificities, including algae, marine mollusks, marine and terrestrial bacteria, and some viruses and fungi. With the progress of structural biology, many kinds of alginate lyases of different polysaccharide lyases families have been characterized by obtaining crystal structures, and the catalytic mechanism has also been elucidated. Combined with various studies, we summarized the source, classification and properties of the alginate lyases from different polysaccharide lyases families. The relationship between substrate specificity and protein sequence was also investigated. PMID:25831216

  1. MendelWeb: An Electronic Science/Math/History Resource for the WWW.

    Science.gov (United States)

    Blumberg, Roger B.

    This paper describes a hypermedia resource, called MendelWeb that integrates elementary biology, discrete mathematics, and the history of science. MendelWeb is constructed from Gregor Menders 1865 paper, "Experiments in Plant Hybridization". An English translation of Mendel's paper, which is considered to mark the birth of classical and…

  2. QR Codes as Finding Aides: Linking Electronic and Print Library Resources

    Science.gov (United States)

    Kane, Danielle; Schneidewind, Jeff

    2011-01-01

    As part of a focused, methodical, and evaluative approach to emerging technologies, QR codes are one of many new technologies being used by the UC Irvine Libraries. QR codes provide simple connections between print and virtual resources. In summer 2010, a small task force began to investigate how QR codes could be used to provide information and…

  3. Screening of Alginate Lyase-Producing Bacteria and Optimization of Media Compositions for Extracellular Alginate Lyase Production.

    Science.gov (United States)

    Tavafi, Hadis; Abdi-Ali, Ahya; Ghadam, Parinaz; Gharavi, Sara

    2017-01-01

    Alginate is a linear polysaccharide consisting of guluronate (polyG) and mannuronate (polyM) subunits. In the initial screening of alginate-degrading bacteria from soil, 10 isolates were able to grow on minimal medium containing alginate. The optimization of cell growth and alginate lyase (algL) production was carried out by the addition of 0.8% alginate and 0.2-0.3 M NaCl to the culture medium. Of 10 isolates, one was selected based on its fast growth rate on minimal 9 medium containing 0.4% sodium alginate. The selected bacterium, identified based on morphological and biochemical characteristics as well as 16S rDNA sequence data, was confirmed to be an isolate belonging to the genus Bacillus and designated as Bacillus sp. TAG8. Resuls: The results showed the ability of Bacillus sp. TAG8 to utilize alginate as a sole carbon source. Bacillus sp. TAG8 growth and algL production were augmented with an increase in sodium alginate concentration and also by the addition of 0.2-0.3 M NaCl. Molecular analysis of TAG8 algL gene showed 99% sequence identity with algL of Pseudomonas aeruginosa PAO1. algL produced by Bacillus sp. TAG8 cleaved both polyM and polyG blocks in alginate molecule as well as acetylated alginate residues, confirming the bifunctionality of the isolated lyase. The identification of novel algL genes from microbial communities constitutes a new approach for exploring lyases with specific activity against bacterial alginates and may thus contribute to the eradication of persistent biofilms from clinical samples.

  4. Screening of Alginate Lyase-Producing Bacteria and Optimization of Media Compositions for Extracellular Alginate Lyase Production

    Science.gov (United States)

    Tavafi, Hadis; Abdi- Ali, Ahya A; Ghadam, Parinaz; Gharavi, Sara

    2017-01-01

    Background: Alginate is a linear polysaccharide consisting of guluronate (polyG) and mannuronate (polyM) subunits. Methods: In the initial screening of alginate-degrading bacteria from soil, 10 isolates were able to grow on minimal medium containing alginate. The optimization of cell growth and alginate lyase (algL) production was carried out by the addition of 0.8% alginate and 0.2-0.3 M NaCl to the culture medium. Of 10 isolates, one was selected based on its fast growth rate on minimal 9 medium containing 0.4% sodium alginate. The selected bacterium, identified based on morphological and biochemical characteristics, as well as 16S rDNA sequence data, was confirmed to be an isolate belonging to the genus Bacillus and designated as Bacillus sp. TAG8. Results: The results showed the ability of Bacillus sp. TAG8 in utilizing alginate as a sole carbon source. Bacillus sp. TAG8 growth and algL production were augmented with an increase in sodium alginate concentration and also by the addition of 0.2-0.3 M NaCl. Molecular analysis of TAG8 algL gene showed 99% sequence identity with algL of Pseudomonas aeruginosa PAO1. The algL produced by Bacillus sp. TAG8 cleaved both polyM and polyG blocks in alginate molecule, as well as acetylated alginate residues, confirming the bifunctionality of the isolated lyase. Conclusion: The identification of novel algL genes from microbial communities constitutes a new approach for exploring lyases with specific activity against bacterial alginates and may thus contribute to the eradication of persistent biofilms from clinical samples. PMID:27432784

  5. Electronic resources at the University of Sharjah medical library: an investigation of students' information-seeking behavior.

    Science.gov (United States)

    Boumarafi, Behdja

    2010-10-01

    Electronic information is becoming prevalent worldwide, and its use is growing exponentially as more and more users are recognizing the potential that it offers in terms of access and delivery. However, with the introduction of new tools for e-information searching and retrieval, users have to readjust their information-seeking behavior to cope with the corresponding changes. The University of Sharjah library is steadily increasing its investment in e-resources to offer ubiquitous access to the growing body of literature in areas that interest the community it serves. This study reports the findings of a survey conducted to investigate the information-seeking behavior of medical students at the medical library. Results showed evidence of use of e-resources, but they did not explicitly establish that some of the major problems mentioned by participants did hinder the information searches of the respondents. An extensive literature review sets the background for the study.

  6. 图书馆电子信息资源利用效果评价研究%Study on Utilization Effect Evaluation of Library Electronic Information Resources

    Institute of Scientific and Technical Information of China (English)

    晋晓强; 贺培风; 何忠印

    2012-01-01

    This paper discusses utilization effect of electronic information resources combining with the characteristics of electronic information resources, makes evaluation system of library electronic information resource utilization effect from three aspects : the library, the users and the data providers, hoping for providing valuable reference for the efficient use of library electronic resources.%本文结合电子信息资源的特性对电子信息资源的利用进行初步探讨,从图书馆、用户和数据服务商三个角度构建图书馆电子信息资源利用效果的评价体系,希望能为图书馆电子信息资源的高效利用提供参考。

  7. An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

    KAUST Repository

    Ramli, Rindra M.

    2017-05-03

    An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

  8. Eavesdropping on Electronic Guidebooks: Observing Learning Resources in Shared Listening Environments.

    Science.gov (United States)

    Woodruff, Allison; Aoki, Paul M.; Grinter, Rebecca E.; Hurst, Amy; Szymanski, Margaret H.; Thornton, James D.

    This paper describes an electronic guidebook, "Sotto Voce," that enables visitors to share audio information by eavesdropping on each others guidebook activity. The first section discusses the design and implementation of the guidebook device, key aspects of its user interface, the design goals for the audio environment, the eavesdropping…

  9. Electronic Resources in a Next-Generation Catalog: The Case of WorldCat Local

    Science.gov (United States)

    Shadle, Steve

    2009-01-01

    In April 2007, the University of Washington Libraries debuted WorldCat Local (WCL), a localized version of the WorldCat database that interoperates with a library's integrated library system and fulfillment services to provide a single-search interface for a library's physical and electronic content. This brief will describe how WCL incorporates a…

  10. Equalizing Access to Electronic Networked Resources: A Model for Rural Libraries in the United States.

    Science.gov (United States)

    Senkevitch, Judith J.; Wolfram, Dietmar

    1994-01-01

    Provides an overview of the current state of networking technology in rural libraries and describes a model for educating rural librarians in accessing electronic networks. Topics discussed include information needs in rural libraries; telecommunications technology access in rural areas; and examples of services to enhance information access.…

  11. Preference and Use of Electronic Information and Resources by Blind/Visually Impaired in NCR Libraries in India

    Directory of Open Access Journals (Sweden)

    Shailendra Kumar

    2013-06-01

    Full Text Available This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

  12. Collaboration in electronic resource provision in university libraries: SHEDL, a Scottish case study

    OpenAIRE

    Kidd, T

    2009-01-01

    This case study examines the growth of collaboration among Scottish higher education institutions. Following a summary of the work of the Scottish Confederation of University and Research Libraries (SCURL), more detailed information is provided on collaboration in the fields of acquisition, licensing, selection, and purchasing. Some of the UK background is outlined, relating to NESLi2 in particular, in order to illuminate the options within Scotland. The origins of negotiations on electronic ...

  13. Characterization of a New Cold-Adapted and Salt-Activated Polysaccharide Lyase Family 7 Alginate Lyase from Pseudoalteromonas sp. SM0524

    Science.gov (United States)

    Chen, Xiu-Lan; Dong, Sheng; Xu, Fei; Dong, Fang; Li, Ping-Yi; Zhang, Xi-Ying; Zhou, Bai-Cheng; Zhang, Yu-Zhong; Xie, Bin-Bin

    2016-01-01

    Marine bacterial alginate lyases play a role in marine alginate degradation and carbon cycling. Although a large number of alginate lyases have been characterized, reports on alginate lyases with special characteristics are still rather less. Here, a gene alyPM encoding an alginate lyase of polysaccharide lyase family 7 (PL7) was cloned from marine Pseudoalteromonas sp. SM0524 and expressed in Escherichia coli. AlyPM shows 41% sequence identity to characterized alginate lyases, indicating that AlyPM is a new PL7 enzyme. The optimal pH for AlyPM activity was 8.5. AlyPM showed the highest activity at 30°C and remained 19% of the highest activity at 5°C. AlyPM was unstable at temperatures above 30°C and had a low Tm of 37°C. These data indicate that AlyPM is a cold-adapted enzyme. Moreover, AlyPM is a salt-activated enzyme. AlyPM activity in 0.5–1.2 M NaCl was sixfolds higher than that in 0 M NaCl, probably caused by a significant increase in substrate affinity, because the Km of AlyPM in 0.5 M NaCl decreased more than 20-folds than that in 0 M NaCl. AlyPM preferably degraded polymannuronate and mainly released dimers and trimers. These data indicate that AlyPM is a new PL7 endo-alginate lyase with special characteristics. PMID:27486451

  14. Internet and electronic resources for inflammatory bowel disease: a primer for providers and patients.

    Science.gov (United States)

    Fortinsky, Kyle J; Fournier, Marc R; Benchimol, Eric I

    2012-06-01

    Patients with inflammatory bowel disease (IBD) are increasingly turning to the Internet to research their condition and engage in discourse on their experiences. This has resulted in new dynamics in the relationship between providers and their patients, with misinformation and advertising potentially presenting barriers to the cooperative patient-provider partnership. This article addresses important issues of online IBD-related health information and social media activity, such as quality, reliability, objectivity, and privacy. We reviewed the medical literature on the quality of online information provided to IBD patients, and summarized the most commonly accessed Websites related to IBD. We also assessed the activity on popular social media sites (such as Facebook, Twitter, and YouTube), and evaluated currently available applications for use by IBD patients and providers on mobile phones and tablets. Through our review of the literature and currently available resources, we developed a list of recommended online resources to strengthen patient participation in their care by providing reliable, comprehensive educational material.

  15. Mesoporous phenylalanine ammonia lyase microspheres with improved stability through calcium carbonate templating.

    Science.gov (United States)

    Cui, Jiandong; Zhao, Yamin; Tan, Zhilei; Zhong, Cheng; Han, Peipei; Jia, Shiru

    2017-05-01

    Cross-linked enzyme aggregates (CLEAs) have recently emerged as a promising method for enzyme immobilization due to its simplicity and low cost. However, a lack of good size and morphological control over the as-prepared CLEAs has limited their practical applications in some cases. Here, monodisperse spherical CLEAs of phenylalanine ammonia lyase (PAL microspheres) were prepared based on CaCO3 microtemplates. The preparation procedure involves filling porous CaCO3 microtemplates with the protein by salt precipitation, glutaraldehyde crosslinking, and dissolution of the microtemplates. The formulation of CaCO3 templates with controlled size was studied in detail. Characterization of the prepared PAL microspheres was investigated. The results showed that the PAL microspheres with high immobilization efficiency (79%) exhibited excellent stability, including increased tolerance to proteolysis, low pH, and denaturants, and excellent mechanical properties. For example, free PAL almost lost all activity after they were incubated in the presence of trypsin for 2min, whereas PAL microspheres still retained 95% of their initial activity. Moreover, scanning electron microscope, transmission electron microscope, and N2 adsorption-desorption isotherms revealed that the resultant PAL microspheres possessed good monodispersity and mesoporous structure instead of the amorphous clusters of conventional CLEAs with few pores. Compared with conventional CLEAs, the monodisperse PAL microspheres with mesoporous make them more potentially useful for biomedical and biotechnological applications.

  16. PECTATE LYASE-LIKE10 is associated with pollen wall development in Brassica campestris.

    Science.gov (United States)

    Jiang, Jingjing; Yao, Lina; Yu, Youjian; Lv, Meiling; Miao, Ying; Cao, Jiashu

    2014-11-01

    PECTATE LYASE-LIKE10 (PLL10) was previously identified as one of the differentially expressed genes both in microspores during the late pollen developmental stages and in pistils during the fertilization process in Chinese cabbage (Brassica campestris ssp. chinensis). Here, antisense-RNA was used to study the functions of BcPLL10 in Chinese cabbage. Abnormal pollen was identified in the transgenic lines (bcpll10-4, -5, and -6). In fertilization experiments, fewer seeds were harvested when the antisense-RNA lines were used as pollen donor. In vivo and in vitro pollen germination assays less germinated pollen tubes were observed in bcpll10 lines. Scanning electron microscopy observation verified that the tryphine materials were over accumulated around the pollen surface and sticked them together in bcpll10. Moreover, transmission electron microscopy observation revealed that the internal endintine was overdeveloped and predominantly occupied the intine, and disturbed the normal proportional distribution of the two layers in the non-germinal furrow region; and no obvious demarcation existed between them in the germinal furrow region in the bcpll10 pollen. Collectively, this study presented a novel PLL gene that played an important role during the pollen wall development in B. campestris, which may also possess potential importance for male sterility usage in agriculture.

  17. Hits identified in library screening demonstrate selective CYP17A1 lyase inhibition.

    Science.gov (United States)

    Krug, Sebastian J; Hu, Qingzhong; Hartmann, Rolf W

    2013-03-01

    A screening of structurally different steroid hormone synthesis inhibitors was performed in order to find a starting point for the development of a new inhibitor of the bifunctional steroidogenic enzyme CYP17A1. Emphasis was placed on determination of selectivity between the two catalytic steps, namely 17α-hydroxylase and C(17,20)-lyase. For that purpose a new inhibition assay has been developed. Hits identified within this novel assay demonstrated selective inhibition of CYP17A1 lyase activity, and thus mark the basis for the development of selective C(17,20)-lyase inhibitors for the treatment of prostate cancer.

  18. A fluorescent substrate for carbon-phosphorus lyase: towards the pathway for organophosphonate metabolism in bacteria

    DEFF Research Database (Denmark)

    He, Shu-Mei; Lou, Yan; Hove-Jensen, Bjarne

    2009-01-01

    Many species of bacteria can use naturally occurring organophosphonates as a source of metabolic phosphate by cleaving the carbon-phosphorus bond with a multi-enzyme pathway collectively called carbon-phosphorus lyase (CP-lyase). Very little is known about the fate of organophosphonates entering...... this pathway. In order to detect metabolic intermediates we have synthesized a fluorescently labelled organophosphonate and show that this is a viable substrate for the CP-lyase pathway in Escherichia coli and that the expected product of CP-bond cleavage is formed. The in vivo competence of one potential...

  19. Structure of the ThDP-dependent enzyme benzaldehyde lyase refined to 1.65 Å resolution

    Energy Technology Data Exchange (ETDEWEB)

    Maraite, Andy; Schmidt, Thomas; Ansörge-Schumacher, Marion B. [Department of Biotechnology, Faculty of Natural Sciences, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Brzozowski, A. Marek; Grogan, Gideon, E-mail: grogan@ysbl.york.ac.uk [Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW (United Kingdom); Department of Biotechnology, Faculty of Natural Sciences, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany)

    2007-07-01

    The X-ray crystal structure of the ThDP-dependent enzyme benzaldehyde lyase has been refined to 1.65 Å. Benzaldehyde lyase (BAL; EC 4.1.2.38) is a thiamine diphosphate (ThDP) dependent enzyme that catalyses the enantioselective carboligation of two molecules of benzaldehyde to form (R)-benzoin. BAL has hence aroused interest for its potential in the industrial synthesis of optically active benzoins and derivatives. The structure of BAL was previously solved to a resolution of 2.6 Å using MAD experiments on a selenomethionine derivative [Mosbacher et al. (2005 ▶), FEBS J.272, 6067–6076]. In this communication of parallel studies, BAL was crystallized in an alternative space group (P2{sub 1}2{sub 1}2{sub 1}) and its structure refined to a resolution of 1.65 Å, allowing detailed observation of the water structure, active-site interactions with ThDP and also the electron density for the co-solvent 2-methyl-2,4-pentanediol (MPD) at hydrophobic patches of the enzyme surface.

  20. Thermodynamics of Enzyme-Catalyzed Reactions: Part 4. Lyases

    Science.gov (United States)

    Goldberg, Robert N.; Tewari, Yadu B.

    1995-09-01

    Equilibrium constants and enthalpy changes for reactions catalyzed by the lyase class of enzymes have been compiled. For each reaction the following information is given: the reference for the data; the reaction studied; the name of the enzyme used and its Enzyme Commission number; the method of measurement; the conditions of measurement (temperature, pH, ionic strength, and the buffer(s) and cofactor(s) used); the data and an evaluation of it; and, sometimes, commentary on the data and on any corrections which have been applied to it or any calculations for which the data have been used. The data from 106 references have been examined and evaluated. Chemical Abstract Service registry numbers are given for the substances involved in these various reactions. There is a cross reference between the substances and the Enzyme Commission numbers of the enzymes used to catalyze the reactions in which the substances participate.

  1. Tissue and method specificities of phenylalanine ammonia-lyase assay.

    Science.gov (United States)

    Kováčik, Jozef; Klejdus, Bořivoj

    2012-09-01

    A large number of studies have estimated phenylalanine ammonia-lyase (PAL) activity because it strongly reacts to various stimuli. Activity of this enzyme has been assayed mainly by means of spectrophotometry, but the precision of this method is poorly known. We compared assays of PAL activity using spectrophotometry and high performance liquid chromatography (HPLC) in two species (Matricaria chamomilla and Arabidopsis thaliana). Additionally, copper-exposed M. chamomilla plants and buffer with additive were also tested. Our data indicate that spectrophotometry both overestimates (leaves of M. chamomilla) and underestimates (leaves and roots of A. thaliana) PAL activity in comparison with HPLC, suggesting interference of UV-absorbing metabolites. HPLC also showed more accurate detection of cinnamic acid in Cu-exposed chamomile roots. Addition of dithiothreitol to the extraction buffer enhanced PAL activity but reduced proteins, indicating an artificial negative effect. A comparison of PAL activity in selected species is also provided.

  2. Structural Snapshots of Heparin Depolymerization by Heparin Lyase I

    Energy Technology Data Exchange (ETDEWEB)

    Han, Young-Hyun; Garron, Marie-Line; Kim, Hye-Yeon; Kim, Wan-Seok; Zhang, Zhenqing; Ryu, Kyeong-Seok; Shaya, David; Xiao, Zhongping; Cheong, Chaejoon; Kim, Yeong Shik; Linhardt, Robert J.; Jeon, Young Ho; Cygler, Miroslaw; (SNU); (Korea BSI); (McGill); (UST-Korea); (Rensselaer)

    2010-01-12

    Heparin lyase I (heparinase I) specifically depolymerizes heparin, cleaving the glycosidic linkage next to iduronic acid. Here, we show the crystal structures of heparinase I from Bacteroides thetaiotaomicron at various stages of the reaction with heparin oligosaccharides before and just after cleavage and product disaccharide. The heparinase I structure is comprised of a {beta}-jellyroll domain harboring a long and deep substrate binding groove and an unusual thumb-resembling extension. This thumb, decorated with many basic residues, is of particular importance in activity especially on short heparin oligosaccharides. Unexpected structural similarity of the active site to that of heparinase II with an ({alpha}/{alpha}){sub 6} fold is observed. Mutational studies and kinetic analysis of this enzyme provide insights into the catalytic mechanism, the substrate recognition, and processivity.

  3. Granulometric composition study of mineral resources using opto-electronic devices and Elsieve software system

    Directory of Open Access Journals (Sweden)

    Kaminski Stanislaw

    2016-01-01

    Full Text Available The use of mechanical sieves has a great impact on measurement results because occurrence of anisometric particles causes undercounting the average size. Such errors can be avoided by using opto-electronic measuring devices that enable measurement of particles from 10 μm up to a few dozen millimetres in size. The results of measurement of each particle size fraction are summed up proportionally to its weight with the use of Elsieve software system and for every type of material particle-size distribution can be obtained. The software allows further statistical interpretation of the results. Beam of infrared radiation identifies size of particles and counts them precisely. Every particle is represented by an electronic impulse proportional to its size. Measurement of particles in aqueous suspension that replaces the hydrometer method can be carried out by using the IPS L analyser (range from 0.2 to 600 μm. The IPS UA analyser (range from 0.5 to 2000 μm is designed for measurement in the air. An ultrasonic adapter enables performing measurements of moist and aggregated particles from 0.5 to 1000 μm. The construction and software system allow to determine second dimension of the particle, its shape coefficient and specific surface area. The AWK 3D analyser (range from 0.2 to 31.5 mm is devoted to measurement of various powdery materials with subsequent determination of particle shape. The AWK B analyser (range from 1 to 130 mm measures materials of thick granulation and shape of the grains. The presented method of measurement repeatedly accelerates and facilitates study of granulometric composition.

  4. 试论图书馆电子资源与纸本资源的协调发展%The coordinated development of library electronic resources and paper resources

    Institute of Scientific and Technical Information of China (English)

    冯雷

    2012-01-01

      纸本资源和电子资源属于公共图书馆文献资源中两个非常重要的资源类型,纸本资源和电子资源的协调发展在图书馆的可持续发展过程中起着非常重要的作用。本文对如何实现图书馆电子资源和纸本资源之间的协调发展进行了探讨,希望能够为图书馆文献资源的管理提供一些参考。%  The paper and electronic resources are two very important types of literature resources of public libraries, the coordinated development of the paper and electronic resources play a very important role in the sustainable development process of the library. This article discusses how to realize the coordinated development of library electronic resources and paper resources, hope to provide some reference for library literature resource management.

  5. Genetics Home Reference: 17 alpha-hydroxylase/17,20-lyase deficiency

    Science.gov (United States)

    ... hypertension), low levels of potassium in the blood (hypokalemia), and abnormal sexual development. The severity of the ... these salt-regulating hormones leads to hypertension and hypokalemia. Loss of 17,20-lyase activity impairs sex ...

  6. High cerebral guanidinoacetate and variable creatine concentrations in argininosuccinate synthetase and lyase deficiency : Implications for treatment?

    NARCIS (Netherlands)

    van Spronsen, F. J.; Reijngoud, D. J.; Verhoeven, N. M.; Soorani-Lunsing, R. J.; Jakobs, C.; Sijens, P. E.

    2006-01-01

    Cerebral creatine and guanidinoacetate and blood and urine metabolites were studied in four patients with argininosuccinate synthetase (ASS) or argininosuccinate lyase (ASL) deficiency receiving large doses of arginine. Urine and blood metabolites varied largely. Cerebral guanidinoacetate was

  7. Isocitrate lyase and the glyoxylate cycle. Progress report, February 15, 1989--February 15, 1990

    Energy Technology Data Exchange (ETDEWEB)

    McFadden, B.A.

    1990-12-31

    Active site modifications of isocitrate lyase (icl) from Escherichia coli are described. In addition directed mutagenesis of icl gene are detailed aimed at varying the charge yet conserving the structure of the enzymes active site.

  8. High cerebral guanidinoacetate and variable creatine concentrations in argininosuccinate synthetase and lyase deficiency : Implications for treatment?

    NARCIS (Netherlands)

    van Spronsen, F. J.; Reijngoud, D. J.; Verhoeven, N. M.; Soorani-Lunsing, R. J.; Jakobs, C.; Sijens, P. E.

    2006-01-01

    Cerebral creatine and guanidinoacetate and blood and urine metabolites were studied in four patients with argininosuccinate synthetase (ASS) or argininosuccinate lyase (ASL) deficiency receiving large doses of arginine. Urine and blood metabolites varied largely. Cerebral guanidinoacetate was increa

  9. On the Development of Electronic Resources and Paper Resources%关于电子资源与纸本资源协调发展的思考和建议

    Institute of Scientific and Technical Information of China (English)

    王军武

    2012-01-01

    In recent years, a large number of electronic resources was introduced to the libraries, which has become an im- portant component of library resource system. However, there are also a lot of hot debates about the following issues, such as how to build a traditional paper resources, how to deal with the relationship between paper resources and electronic resources, how to build a library resources development system, etc. These problems also confused many librarians who are building resources in the library. With the combination with the opinions from some experts, research scholars, the paper proposed some guiding principles to deal with the relationship between electronic resources and paper resources. Taking all the aspects into consideration, such as the concepts of the library, the funding of the resources, the policies and structure of the library, cooperative development, the paper also proposes some measures for the development of electronic resources and paper resources.%在复合图书馆环境下,如何协调发展电子资源与纸本资源是图书馆界专家、学者研究和探讨的热点问题,也是许多图书馆工作者在文献资源建设实践中十分困惑的问题。文章结合有关专家、学者的研究成果及图书馆的相关案例,概述了电子资源与纸本资源协调发展应遵循的指导性原则,并从馆藏理念、经费投入、馆藏政策、馆藏结构、合作发展、服务利用等几个方面提出了协调发展电子资源与纸本资源的若干举措。

  10. In vivo synthesis of histidine by a cloned histidine ammonia-lyase in Escherichia coli.

    OpenAIRE

    Fuchs, R L; Kane, J F

    1985-01-01

    Histidine ammonia-lyase catalyzes the first step in histidine catabolism, the deamination of histidine to urocanate and ammonia. In vitro experiments have shown that histidine ammonia-lyase also can catalyze the reverse (amination) reaction, histidine synthesis, relatively efficiently under extreme reaction conditions (4 M NH4OH, pH 10). An Escherichia coli hisB deletion strain was transformed with a pBR322 derivative plasmid (pCB101) containing the entire Klebsiella aerogenes histidine utili...

  11. Encapsulated Escherichia coli in alginate beads capable of secreting a heterologous pectin lyase

    Directory of Open Access Journals (Sweden)

    Trikka Fotini A

    2005-12-01

    Full Text Available Abstract Background Production of heterologous proteins in the E. coli periplasm, or into the extracellular fluid has many advantages; therefore naturally occurring signal peptides are selected for proteins translocation. The aim of this study was the production in high yields of a recombinant pectin lyase that is efficiently secreted and the encapsulation of transformed E. coli cells for pectin degradation in a biotechnological process. Results The nucleotide sequence of Bacillus subtilis α-amylase's signal peptide was fused to the N-terminal of an heterologously expressed pectin lyase in E. coli BL21 [DE3]. Thus pectin lyase secretion was achieved into the extracellular growth medium. E. coli cells harboring the recombinant plasmid heterologously express pectin lyase to around 22% of the total cellular proteins, as it was estimated by SDS-PAGE and image analysis. IPTG induces the heterologously expressed enzyme, which is initially distributed extracellularly (7 hour and later on at the periplasmic (9 hours or cytosolic fraction (20 hours. No pectin lyase activity was found in the membranes fraction and in the inclusion bodies. Encapsulation of the recombinant strains of E. coli in alginate or alginate/silica beads 1:5 showed that pectin lyase could degrade effectively its substrate, for at least ten operational cycles. Conclusion Secretion of an heterologously overexpressed pectin lyase in E. coli BL21 [DE3] was achieved in this study. For this purpose the signal peptide of α-amylase from B. subtilis was fused to the N-terminal domain of pectin lyase. Encapsulated E. coli BL21 [DE3] cells harboring pET29c/exPNL were used successfully for pectin degradation up to ten operational cycles indicating that under special conditions this might have biotechnological implementations.

  12. Alginate Lyase Exhibits Catalysis-Independent Biofilm Dispersion and Antibiotic Synergy

    OpenAIRE

    Lamppa, John W.; Karl E Griswold

    2013-01-01

    More than 2 decades of study support the hypothesis that alginate lyases are promising therapeutic candidates for treating mucoid Pseudomonas aeruginosa infections. In particular, the enzymes' ability to degrade alginate, a key component of mucoid biofilm matrix, has been the presumed mechanism by which they disrupt biofilms and enhance antibiotic efficacy. The systematic studies reported here show that, in an in vitro model, alginate lyase dispersion of P. aeruginosa biofilms and enzyme syne...

  13. Characterization of AlgMsp, an Alginate Lyase from Microbulbifer sp. 6532A

    OpenAIRE

    Swift, Steven M.; Hudgens, Jeffrey W.; Heselpoth, Ryan D.; Bales, Patrick M.; Daniel C. Nelson

    2014-01-01

    Alginate is a polysaccharide produced by certain seaweeds and bacteria that consists of mannuronic acid and guluronic acid residues. Seaweed alginate is used in food and industrial chemical processes, while the biosynthesis of bacterial alginate is associated with pathogenic Pseudomonas aeruginosa. Alginate lyases cleave this polysaccharide into short oligo-uronates and thus have the potential to be utilized for both industrial and medicinal applications. An alginate lyase gene, algMsp, from ...

  14. Cloning of a Putative Pectate Lyase Gene Expressed in the Subventral Esophageal Glands of Heterodera glycines.

    Science.gov (United States)

    De Boer, J M; Davis, E L; Hussey, R S; Popeijus, H; Smant, G; Baum, T J

    2002-03-01

    We report the cloning of a Heterodera glycines cDNA that has 72% identity at the amino acid level to a pectate lyase from Globodera rostochiensis. In situ hybridizations showed that the corresponding gene (Hg-pel-1) is expressed in the subventral esophageal gland cells of second-stage juveniles. The deduced amino acid sequence of the H. glycines cDNA shows homology to class III pectate lyases of bacterial and fungal origin.

  15. Characterization of AlgMsp, an alginate lyase from Microbulbifer sp. 6532A.

    Science.gov (United States)

    Swift, Steven M; Hudgens, Jeffrey W; Heselpoth, Ryan D; Bales, Patrick M; Nelson, Daniel C

    2014-01-01

    Alginate is a polysaccharide produced by certain seaweeds and bacteria that consists of mannuronic acid and guluronic acid residues. Seaweed alginate is used in food and industrial chemical processes, while the biosynthesis of bacterial alginate is associated with pathogenic Pseudomonas aeruginosa. Alginate lyases cleave this polysaccharide into short oligo-uronates and thus have the potential to be utilized for both industrial and medicinal applications. An alginate lyase gene, algMsp, from Microbulbifer sp. 6532A, was synthesized as an E.coli codon-optimized clone. The resulting 37 kDa recombinant protein, AlgMsp, was expressed, purified and characterized. The alginate lyase displayed highest activity at pH 8 and 0.2 M NaCl. Activity of the alginate lyase was greatest at 50°C; however the enzyme was not stable over time when incubated at 50°C. The alginate lyase was still highly active at 25°C and displayed little or no loss of activity after 24 hours at 25°C. The activity of AlgMsp was not dependent on the presence of divalent cations. Comparing activity of the lyase against polymannuronic acid and polyguluronic acid substrates showed a higher turnover rate for polymannuronic acid. However, AlgMSP exhibited greater catalytic efficiency with the polyguluronic acid substrate. Prolonged AlgMsp-mediated degradation of alginate produced dimer, trimer, tetramer, and pentamer oligo-uronates.

  16. Characterization of AlgMsp, an alginate lyase from Microbulbifer sp. 6532A.

    Directory of Open Access Journals (Sweden)

    Steven M Swift

    Full Text Available Alginate is a polysaccharide produced by certain seaweeds and bacteria that consists of mannuronic acid and guluronic acid residues. Seaweed alginate is used in food and industrial chemical processes, while the biosynthesis of bacterial alginate is associated with pathogenic Pseudomonas aeruginosa. Alginate lyases cleave this polysaccharide into short oligo-uronates and thus have the potential to be utilized for both industrial and medicinal applications. An alginate lyase gene, algMsp, from Microbulbifer sp. 6532A, was synthesized as an E.coli codon-optimized clone. The resulting 37 kDa recombinant protein, AlgMsp, was expressed, purified and characterized. The alginate lyase displayed highest activity at pH 8 and 0.2 M NaCl. Activity of the alginate lyase was greatest at 50°C; however the enzyme was not stable over time when incubated at 50°C. The alginate lyase was still highly active at 25°C and displayed little or no loss of activity after 24 hours at 25°C. The activity of AlgMsp was not dependent on the presence of divalent cations. Comparing activity of the lyase against polymannuronic acid and polyguluronic acid substrates showed a higher turnover rate for polymannuronic acid. However, AlgMSP exhibited greater catalytic efficiency with the polyguluronic acid substrate. Prolonged AlgMsp-mediated degradation of alginate produced dimer, trimer, tetramer, and pentamer oligo-uronates.

  17. Green Supply Chain Collaboration for Fashionable Consumer Electronics Products under Third-Party Power Intervention—A Resource Dependence Perspective

    Directory of Open Access Journals (Sweden)

    Jiuh-Biing Sheu

    2014-05-01

    Full Text Available Under third-party power intervention (TPPI, which increases uncertainty in task environments, complex channel power interplays and restructuring are indispensable among green supply chain members as they move toward sustainable collaborative relationships for increased viability and competitive advantage. From the resource dependence perspective, this work presents a novel conceptual model to investigate the influence of political and social power on channel power restructuring and induced green supply chain collaboration in brander-retailer bidirectional green supply chains of fashionable consumer electronics products (FCEPs. An FCEP refers to the consumer electronics product (e.g., personal computers, mobile phones, computer notebooks, and game consoles with the features of a well-known brand associated, a short product lifecycle, timely and fashionable design fit for market trends, and quick responsiveness to the variations of market demands. The proposed model is tested empirically using questionnaire data obtained from retailers in the FCEP brander-retailer distribution channels. Analytical results reveal that as an extension of political and social power, TPPI positively affects the reciprocal interdependence of dyadic members and reduces power asymmetry, thereby enhancing the collaborative relationship of dyadic members and leading to improved green supply chain performance. Therein, reciprocal interdependence underlying collaborative relationship is the key to reducing the external environmental uncertainties in the TPPI context.

  18. Mutational analysis of phenylalanine ammonia lyase to improve reactions rates for various substrates.

    Science.gov (United States)

    Bartsch, Sebastian; Bornscheuer, Uwe T

    2010-12-01

    Phenylalanine ammonia lyases (PAL) catalyze the reversible, non-reductive amination of trans-cinnamic acid to l-phenylalanine in the presence of high ammonia concentrations. Since neither cofactor recycling nor other additives are needed and by this asymmetric synthesis theoretical yields of 100% can be reached, it is an interesting reaction for industrial processes. In this study we demonstrate the superior properties of p-nitro-cinnamic acid (p-n-CA) in the amination reaction using the PAL from Petroselinum crispum (pcPAL). By focused-directed evolution, three mutants were identified showing increased reaction rates and decreased substrate inhibition. Together, the F137V mutant with p-n-CA showed a 15-fold increased reaction rate compared with the pcPAL WT with the natural cinnamic acid. The high reaction rates were also proven in preparative scale experiments. Activities towards other p-substituted cinnamic acids showing different electronic effects of the substituent were analyzed. Focused-directed evolution around the carboxylic acid- and amine-binding site always decreased PAL activity, due to a sensitive H-bond network.

  19. Electronic medical record data to identify variables associated with a fibromyalgia diagnosis: importance of health care resource utilization

    Directory of Open Access Journals (Sweden)

    Masters ET

    2015-03-01

    Full Text Available Elizabeth T Masters,1 Jack Mardekian,1 Birol Emir,1 Andrew Clair,1 Max Kuhn,2 Stuart L Silverman,31Pfizer, Inc., New York, NY, 2Pfizer, Inc., Groton, CT, 3Cedars-Sinai Medical Center, Los Angeles, CA, USABackground: Diagnosis of fibromyalgia (FM is often challenging. Identifying factors associated with an FM diagnosis may guide health care providers in implementing appropriate diagnostic and management strategies.Methods: This retrospective study used the de-identified Humedica electronic medical record (EMR database to identify variables associated with an FM diagnosis. Cases (n=4,296 were subjects ≥18 years old with ≥2 International Classification of Diseases, Ninth Revision (ICD-9 codes for FM (729.1 ≥30 days apart during 2012, associated with an integrated delivery network, with ≥1 encounter with a health care provider in 2011 and 2012. Controls without FM (no-FM; n=583,665 did not have the ICD-9 codes for FM. Demographic, clinical, and health care resource utilization variables were extracted from structured EMR data. Univariate analysis identified variables showing significant differences between the cohorts based on odds ratios (ORs.Results: Consistent with FM epidemiology, FM subjects were predominantly female (78.7% vs 64.5%; P<0.0001 and slightly older (mean age 53.3 vs 52.7 years; P=0.0318. Relative to the no-FM cohort, the FM cohort was characterized by a higher prevalence of nearly all evaluated comorbidities; the ORs suggested a higher likelihood of an FM diagnosis (P<0.0001, especially for musculoskeletal and neuropathic pain conditions (OR 3.1 for each condition. Variables potentially associated with an FM diagnosis included higher levels of use of specific health care resources including emergency-room visits, outpatient visits, hospitalizations, and medications. Units used per subject for emergency-room visits, outpatient visits, hospitalizations, and medications were also significantly higher in the FM cohort (P<0

  20. Survey on User Satisfaction of Electronic Resources in University Libraries%高校图书馆电子资源用户满意度调查

    Institute of Scientific and Technical Information of China (English)

    陈姚竹; 马东

    2011-01-01

    通过分析影响用户对图书馆电子资源利用的因素,以美国顾客满意度指数模型为基础,提出关于各个因素的测量指标,对高校图书馆电子资源用户满意度进行测量。%Through analyzing the influencing factors on utilizing library electronic resources, based on the model of American customer satisfaction index, the paper puts forward corresponding measurement indexes, and then measures the user satisfaction on electronic resources of university library

  1. Characterization of an Eukaryotic PL-7 Alginate Lyase in the Marine Red Alga Pyropia yezoensis.

    Science.gov (United States)

    Inoue, Akira; Mashino, Chieco; Uji, Toshiki; Saga, Naotsune; Mikami, Koji; Ojima, Takao

    2015-08-01

    Alginate lyases belonging to polysaccharide lyase family-7 (PL-7) are the most well studied on their structures and functions among whole alginate lyases. However, all characterized PL-7 alginate lyases are from prokaryotic bacteria cells. Here we report the first identification of eukaryotic PL-7 alginate lyase from marine red alga Pyropia yezoensis. The cDNA encoding an alginate lyase PyAly was cloned and was used for the construction of recombinant PyAly (rPyAly) expression system in Escherichia coli. Purified rPyAly was assayed to identify its enzymatic properties. Its expression pattern in P. yessoensis was also investigated. PyAly is likely a secreted protein consisting of an N-terminal signal peptide of 25 residues and a catalytic domain of 216 residues. The amino-acid sequence of the catalytic domain showed 19-29% identities to those of bacterial characterized alginate lyases classified into family PL-7. Recombinant PyAly protein, rPyAly, which was produced with E. coli BL21(DE3) by cold-inducible expression system, drastically decreased the viscosity of alginate solution in the early stage of reaction. The most preferable substrate for rPyAly was the poly(M) of alginate with an optimal temperature and pH at 35(o)C and 8.0, respectively. After reaction, unsaturated tri- and tetra-saccharides were produced from poly(M) as major end products. These enzymatic properties indicated that PyAly is an endolytic alginate lyase belonging to PL-7. Moreover, we found that the PyAly gene is split into 4 exons with 3 introns. PyAly was also specifically expressed in the gametophytic haplopid stage. This study demonstrates that PyAly in marine red alga P. yezoensis is a novel PL-7 alginate lyase with an endolytic manner. PyAly is a gametophyte-specifically expressed protein and its structural gene is composed of four exons and three introns. Thus, PyAly is the first enzymatically characterized eukaryotic PL-7 alginate lyase.

  2. Design of thermostable rhamnogalacturonan lyase mutants from Bacillus licheniformis by combination of targeted single point mutations

    DEFF Research Database (Denmark)

    da Silva, Ines Isabel Cardoso Rodrigues; Jers, Carsten; Otten, Harm

    2014-01-01

    Rhamnogalacturonan I lyases (RGI lyases) (EC 4.2.2.-) catalyze cleavage of α-1,4 bonds between rhamnose and galacturonic acid in the backbone of pectins by β-elimination. In the present study, targeted improvement of the thermostability of a PL family 11 RGI lyase from Bacillus licheniformis (DSM......, were obtained due to additive stabilizing effects of single amino acid mutations (E434L, G55V, and G326E) compared to the wild type. The crystal structure of the B. licheniformis wild-type RGI lyase was also determined; the structural analysis corroborated that especially mutation of charged amino...

  3. Optimization of culturing condition and medium composition for the production of alginate lyase by a marine Vibrio sp. YKW-34

    Science.gov (United States)

    Fu, Xiaoting; Lin, Hong; Kim, Sang Moo

    2008-02-01

    Carbohydrases secreted by marine Vibrio sp. YKW-34 with strong Laminaria cell wall degrading ability were screened, and among them alginate lyase was found to be dominant. The effects of medium composition and culturing condition on the production of alginate lyase by marine Vibrio sp. YKW-34 in flask were investigated in this study. In the culture medium of marine broth, no alginate lyase was produced. The activity of the alginate lyase, after being induced, reached 5 UmL-1. The best inoculum volume and inoculum age were 10% and 12 h, respectively. The optimal temperature for alginate lyase production was 25°C. The fermentation medium was composed of 0.5% of Laminaria powder and 0.2% of KNO3 with an initial acidity of pH 8.0. Alginate could induce alginate lyase production but not as efficiently as Laminaria powder did. The addition of fucoidan, cellulose and glucose had negative effect on the alginate lyase production. Other kinds of nitrogen sources, such as yeast extract, beef extract and peptone, had positive effect on the growth of the microorganism and negative effect on alginate lyase production. In addition, the time course of alginate lyase production under the optimized condition was described. The optimal harvest time was 48 h.

  4. Optimization of Culturing Condition and Medium Composition for the Production of Alginate Lyase by a Marine Vibrio sp. YKW-34

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Carbohydrases secreted by marine Vibrio sp. YKW-34 with strong Laminaria cell wall degrading ability were screened,and among them alginate lyase was found to be dominant. The effects of medium composition and culturing condition on the production of alginate lyase by marine Vibrio sp. YKW-34 in flask were investigated in this study. In the culture medium of marine broth, no alginate lyase was produced. The activity of the alginate lyase, after being induced, reached 5 UmL-1. The best inoculum volume and inoculum age were 10% and 12 h, respectively. The optimal temperature for alginate lyase production was 25℃. The fermentation medium was composed of 0.5% of Laminaria powder and 0.2% of KNO3 with an initial acidity of pH 8.0. Alginate could induce alginate lyase production but not as efficiently as Laminaria powder did. The addition of fucoidan, cellulose and glucose had negative effect on the alginate lyase production. Other kinds of nitrogen sources, such as yeast extract, beef extract and peptone, had positive effect on the growth of the microorganism and negative effect on alginate lyase production. In addition, the time course of alginate lyase production under the optimized condition was described. The optimal harvest time was 48 h.

  5. Bioactivation of cysteine conjugates of 1-nitropyrene oxides by cysteine conjugate beta-lyase purified from Peptostreptococcus magnus.

    OpenAIRE

    Kataoka, K; Kinouchi, T; Akimoto, S; Ohnishi, Y

    1995-01-01

    To determine the role of cysteine conjugate beta-lyase (beta-lyase) in the metabolism of mutagenic nitropolycyclic aromatic hydrocarbons, we determined the effect of beta-lyase on the mutagenicities and DNA binding of cysteine conjugates of 4,5-epoxy-4,5-dihydro-1-nitropyrene (1-NP 4,5-oxide) and 9,10-epoxy-9,10-dihydro-1-nitropyrene (1-NP 9,10-oxide), which are detoxified metabolites of the mutagenic compound 1-nitropyrene. We purified beta-lyase from Peptostreptococcus magnus GAI0663, since...

  6. Production and Purification of a Novel Xanthan Lyase from a Xanthan-Degrading Microbacterium sp. Strain XT11

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2014-01-01

    Full Text Available A xanthan lyase was produced and purified from the culture supernatant of an excellent xanthan-modifying strain Microbacterium sp. XT11. Xanthan lyase was induced by xanthan but was inhibited by its structural monomer glucose. Its production by strain XT11 is much higher than that by all other reported strains. The purified xanthan lyase has a molecular mass of 110 kDa and a specific activity of 28.2 U/mg that was much higher than that of both Paenibacillus and Bacillus lyases. It was specific on the pyruvated mannosyl residue in the intact xanthan molecule, but about 50% lyase activity remained when xanthan was partially depyruvated. Xanthan lyase was optimally active at pH 6.0–6.5 and 40°C and alkali-tolerant at a high pH value of 11.0. The metal ions including K+, Ca2+, Na+, Mg2+, Mn2+, and Li+ strongly stimulated xanthan lyase activity but ions Zn2+ and Cu2+ were its inhibitor. Xanthan lyase should be a novel enzyme different from the other xanthan lyases ever reported.

  7. Development of an electronic medical record based alert for risk of HIV treatment failure in a low-resource setting.

    Directory of Open Access Journals (Sweden)

    Nancy Puttkammer

    Full Text Available BACKGROUND: The adoption of electronic medical record systems in resource-limited settings can help clinicians monitor patients' adherence to HIV antiretroviral therapy (ART and identify patients at risk of future ART failure, allowing resources to be targeted to those most at risk. METHODS: Among adult patients enrolled on ART from 2005-2013 at two large, public-sector hospitals in Haiti, ART failure was assessed after 6-12 months on treatment, based on the World Health Organization's immunologic and clinical criteria. We identified models for predicting ART failure based on ART adherence measures and other patient characteristics. We assessed performance of candidate models using area under the receiver operating curve, and validated results using a randomly-split data sample. The selected prediction model was used to generate a risk score, and its ability to differentiate ART failure risk over a 42-month follow-up period was tested using stratified Kaplan Meier survival curves. RESULTS: Among 923 patients with CD4 results available during the period 6-12 months after ART initiation, 196 (21.2% met ART failure criteria. The pharmacy-based proportion of days covered (PDC measure performed best among five possible ART adherence measures at predicting ART failure. Average PDC during the first 6 months on ART was 79.0% among cases of ART failure and 88.6% among cases of non-failure (p<0.01. When additional information including sex, baseline CD4, and duration of enrollment in HIV care prior to ART initiation were added to PDC, the risk score differentiated between those who did and did not meet failure criteria over 42 months following ART initiation. CONCLUSIONS: Pharmacy data are most useful for new ART adherence alerts within iSanté. Such alerts offer potential to help clinicians identify patients at high risk of ART failure so that they can be targeted with adherence support interventions, before ART failure occurs.

  8. ATP citrate lyase inhibitors as novel cancer therapeutic agents.

    Science.gov (United States)

    Zu, Xu-Yu; Zhang, Qing-Hai; Liu, Jiang-Hua; Cao, Ren-Xian; Zhong, Jing; Yi, Guang-Hui; Quan, Zhi-Hua; Pizzorno, Giuseppe

    2012-05-01

    ATP citrate lyase (ACL or ACLY) is an extra-mitochondrial enzyme widely distributed in various human and animal tissues. ACL links glucose and lipid metabolism by catalyzing the formation of acetyl-CoA and oxaloacetate from citrate produced by glycolysis in the presence of ATP and CoA. ACL is aberrantly expressed in many immortalized cells and tumors, such as breast, liver, colon, lung and prostate cancers, and is correlated reversely with tumor stage and differentiation, serving as a negative prognostic marker. ACL is an upstream enzyme of the long chain fatty acid synthesis, providing acetyl-CoA as an essential component of the fatty acid synthesis. Therefore, ACL is a key enzyme of cellular lipogenesis and potent target for cancer therapy. As a hypolipidemic strategy of metabolic syndrome and cancer treatment, many small chemicals targeting ACL have been designed and developed. This review article provides an update for the research and development of ACL inhibitors with a focus on their patent status, offering a new insight into their potential application.

  9. Cystathionine γ-lyase deficiency mediates neurodegeneration in Huntington's disease.

    Science.gov (United States)

    Paul, Bindu D; Sbodio, Juan I; Xu, Risheng; Vandiver, M Scott; Cha, Jiyoung Y; Snowman, Adele M; Snyder, Solomon H

    2014-05-01

    Huntington's disease is an autosomal dominant disease associated with a mutation in the gene encoding huntingtin (Htt) leading to expanded polyglutamine repeats of mutant Htt (mHtt) that elicit oxidative stress, neurotoxicity, and motor and behavioural changes. Huntington's disease is characterized by highly selective and profound damage to the corpus striatum, which regulates motor function. Striatal selectivity of Huntington's disease may reflect the striatally selective small G protein Rhes binding to mHtt and enhancing its neurotoxicity. Specific molecular mechanisms by which mHtt elicits neurodegeneration have been hard to determine. Here we show a major depletion of cystathionine γ-lyase (CSE), the biosynthetic enzyme for cysteine, in Huntington's disease tissues, which may mediate Huntington's disease pathophysiology. The defect occurs at the transcriptional level and seems to reflect influences of mHtt on specificity protein 1, a transcriptional activator for CSE. Consistent with the notion of loss of CSE as a pathogenic mechanism, supplementation with cysteine reverses abnormalities in cultures of Huntington's disease tissues and in intact mouse models of Huntington's disease, suggesting therapeutic potential.

  10. Phenylalanine ammonia-lyase through evolution: A bioinformatic approach

    Directory of Open Access Journals (Sweden)

    Shiva Hemmati

    2015-03-01

    Full Text Available Phenylalanine ammonia-lyase (PAL is the first entry enzyme of the phenylpropanoid pathway that converts phenylalanine to cinnamic acid which is the precursor of various secondary metabolites. PAL is recently formulated for phenylketonuric patients in pegylated forms; therefore, screening a PAL with the highest affinity to the substrate is of a great importance. PAL exists in all higher plants and some fungi and few bacteria. Ancestors of land plants have been adopted by evolving metabolic pathways. A multi-gene family encodes PAL by gene duplication events in most plants. In this study, the taxonomic distribution and phylogeny of pal gene found in land plants, fungi and bacteria have been analyzed. It seems that the ancestor of plants acquired a pal gene via horizontal gene transfer in symbioses with bacteria and fungi. Gymnosperms have kept a diverse set of pal genes that arose from gene duplication events. In angiosperms, after the divergence of dicotyledons from monocots, pal genes were duplicated many times. The close paralogues of pal genes in some species indicate expansion of gene families after the divergence in plant pal gene evolution. Interestingly, some of the plant pals clustered by species in a way that pals within one species are more closely related to each other than to homologs in the other species which indicates this duplication event occurred more recently.

  11. Genomic Characterization of Phenylalanine Ammonia Lyase Gene in Buckwheat.

    Directory of Open Access Journals (Sweden)

    Karthikeyan Thiyagarajan

    Full Text Available Phenylalanine Ammonia Lyase (PAL gene which plays a key role in bio-synthesis of medicinally important compounds, Rutin/quercetin was sequence characterized for its efficient genomics application. These compounds possessing anti-diabetic and anti-cancer properties and are predominantly produced by Fagopyrum spp. In the present study, PAL gene was sequenced from three Fagopyrum spp. (F. tataricum, F. esculentum and F. dibotrys and showed the presence of three SNPs and four insertion/deletions at intra and inter specific level. Among them, the potential SNP (position 949th bp G>C with Parsimony Informative Site was selected and successfully utilised to individuate the zygosity/allelic variation of 16 F. tataricum varieties. Insertion mutations were identified in coding region, which resulted the change of a stretch of 39 amino acids on the putative protein. Our Study revealed that autogamous species (F. tataricum has lower frequency of observed SNPs as compared to allogamous species (F. dibotrys and F. esculentum. The identified SNPs in F. tataricum didn't result to amino acid change, while in other two species it caused both conservative and non-conservative variations. Consistent pattern of SNPs across the species revealed their phylogenetic importance. We found two groups of F. tataricum and one of them was closely related with F. dibotrys. Sequence characterization information of PAL gene reported in present investigation can be utilized in genetic improvement of buckwheat in reference to its medicinal value.

  12. The BRIGHTEN Program: Implementation and Evaluation of a Program to Bridge Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking

    Science.gov (United States)

    Emery, Erin E.; Lapidos, Stan; Eisenstein, Amy R.; Ivan, Iulia I.; Golden, Robyn L.

    2012-01-01

    Purpose: To demonstrate the feasibility of the BRIGHTEN Program (Bridging Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking), an interdisciplinary team intervention for assessing and treating older adults for depression in outpatient primary and specialty medical clinics. The BRIGHTEN team collaborates "virtually"…

  13. The module of methodical support in system of electronic educational resources as the innovative element of the modern maintenance of formation

    Directory of Open Access Journals (Sweden)

    Ольга Николаевна Крылова

    2009-06-01

    Full Text Available The article introduces some results of research, which were devoted to evaluation of tearches' mobility to introduce innovations in the contents of education. The author considers innovative potential of modules of the methodical support for system of electronic educational resources.

  14. Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

    Science.gov (United States)

    Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

    2013-01-01

    In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

  15. The BRIGHTEN Program: Implementation and Evaluation of a Program to Bridge Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking

    Science.gov (United States)

    Emery, Erin E.; Lapidos, Stan; Eisenstein, Amy R.; Ivan, Iulia I.; Golden, Robyn L.

    2012-01-01

    Purpose: To demonstrate the feasibility of the BRIGHTEN Program (Bridging Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking), an interdisciplinary team intervention for assessing and treating older adults for depression in outpatient primary and specialty medical clinics. The BRIGHTEN team collaborates "virtually"…

  16. Electronic Information Resources (EIR Adoption in Private University Libraries: The Moderating Effect of Productivity and Relative Advantage on Perceived Usefulness

    Directory of Open Access Journals (Sweden)

    Izuagbe, Roland

    2016-03-01

    Full Text Available The study tested a hybrid model with constructs drawn from the Technology Acceptance Model (TAM and Diffusion of Innovation (DOI theory in order to examine the moderating effect of productivity and relative advantage (RA on perceived usefulness (PU vis-à-vis electronic information resources (EIR adoption in private university libraries in Ogun and Osun States of Nigeria. The descriptive research design was adopted in the study. The population consisted of 61 (55.0% librarians and 50 (45.0% library officers (totaling 116—100% in Babcock University, Bells University, Covenant University, Bowen University, Oduduwa University, and Redeemer's University. Purposive sampling procedure was adopted after which total enumeration was used since the total population is small. The questionnaire was used for data collection. Of the 116 copies of the questionnaire administered, 111 (95.7% were found usable. The instrument was structured based on a 4-point Likert agreement scale of Strongly Agree, Agree, Disagree, and Strongly Disagree. Data were analyzed using descriptive statistics like tables of frequency counts and percentage. The findings revealed that productivity and relative advantage are significant moderators of perceived usefulness of EIR adoption in private university libraries in Ogun and Osun States, Nigeria.

  17. Altered Fermentative Metabolism in Chlamydomonas reinhardtii Mutants Lacking Pyruvate Formate Lyase and Both Pyruvate Formate Lyase and Alcohol Dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Catalanotti, C.; Dubini, A.; Subramanian, V.; Yang, W. Q.; Magneschi, L.; Mus, F.; Seibert, M.; Posewitz, M. C.; Grossman, A. R.

    2012-02-01

    Chlamydomonas reinhardtii, a unicellular green alga, often experiences hypoxic/anoxic soil conditions that activate fermentation metabolism. We isolated three Chlamydomonas mutants disrupted for the pyruvate formate lyase (PFL1) gene; the encoded PFL1 protein catalyzes a major fermentative pathway in wild-type Chlamydomonas cells. When the pfl1 mutants were subjected to dark fermentative conditions, they displayed an increased flux of pyruvate to lactate, elevated pyruvate decarboxylation, ethanol accumulation, diminished pyruvate oxidation by pyruvate ferredoxin oxidoreductase, and lowered H2 production. The pfl1-1 mutant also accumulated high intracellular levels of lactate, succinate, alanine, malate, and fumarate. To further probe the system, we generated a double mutant (pfl1-1 adh1) that is unable to synthesize both formate and ethanol. This strain, like the pfl1 mutants, secreted lactate, but it also exhibited a significant increase in the levels of extracellular glycerol, acetate, and intracellular reduced sugars and a decrease in dark, fermentative H2 production. Whereas wild-type Chlamydomonas fermentation primarily produces formate and ethanol, the double mutant reroutes glycolytic carbon to lactate and glycerol. Although the metabolic adjustments observed in the mutants facilitate NADH reoxidation and sustained glycolysis under dark, anoxic conditions, the observed changes could not have been predicted given our current knowledge of the regulation of fermentation metabolism.

  18. Probing the structure of glucan lyases – the lytic members of GH31 - by sequence analysis, circular dichroism and proteolysis

    DEFF Research Database (Denmark)

    Ernst, Heidi; Lo Leggio, Leila; Yu, Shukun

    2005-01-01

    Glucan lyase (GL) is a polysaccharide lyase with unique characteristics. It is involved in an alternative pathway for the degradation of alpha-glucans, the anhydrofructose pathway. Sequence similarity suggests that this lytic enzyme belongs to glycoside hydrolase family 31, for which until very r...

  19. The bifunctional role of LiuE from Pseudomonas aeruginosa, displays additionally HIHG-CoA lyase enzymatic activity.

    Science.gov (United States)

    Chávez-Avilés, Mauricio; Díaz-Pérez, Alma Laura; Campos-García, Jesús

    2010-04-01

    Pseudomonas aeruginosa is able to utilize leucine/isovalerate and acyclic terpenes as sole carbon sources. Key enzymes which play an important role in these catabolic pathways are 3-hydroxy-3-methylglutaryl-coenzyme A (CoA) lyase (EC 4.1.3.4; HMG-CoA lyase) and the 3-hydroxy-3-isohexenylglutaryl-CoA lyase (EC 4.1.2.26; HIHG-CoA lyase), respectively. HMG-CoA lyase is encoded by the liuE gene while the gene for HIHG-CoA lyase remains unidentified. A mutant in the liuE gene was unable to utilize both leucine/isovalerate and acyclic terpenes indicates an involvement of liuE in both catabolic pathways (Chávez-Avilés et al. 2009, FEMS Microbiol Lett 296:117-123). The LiuE protein was purified as a His-tagged recombinant protein and in addition to show HMG-CoA lyase activity (Chávez-Avilés et al. 2009, FEMS Microbiol Lett 296:117-123), also displays HIHG-CoA lyase activity, indicating a bifunctional role in both the leucine/isovalerate and acyclic terpenes catabolic pathways.

  20. Identification of amino acid residues critical for catalysis and stability in Aspergillus niger family 1 pectin lyase A

    NARCIS (Netherlands)

    Sanchez-Torres, P.; Visser, J.; Benen, J.A.E.

    2003-01-01

    Site-directed-mutagenesis studies were performed on family 1 pectin lyase A (PL1A) from Aspergillus niger to gain insight into the reaction mechanism for the pectin lyase-catalysed beta-elimination cleavage of methylesterified polygalacturonic acid and to stabilize the enzyme at slightly basic pH. O

  1. Probing the structure of glucan lyases – the lytic members of GH31 - by sequence analysis, circular dichroism and proteolysis

    DEFF Research Database (Denmark)

    Ernst, Heidi; Lo Leggio, Leila; Yu, Shukun

    2005-01-01

    Glucan lyase (GL) is a polysaccharide lyase with unique characteristics. It is involved in an alternative pathway for the degradation of alpha-glucans, the anhydrofructose pathway. Sequence similarity suggests that this lytic enzyme belongs to glycoside hydrolase family 31, for which until very r...

  2. Identification of amino acid residues critical for catalysis and stability in Aspergillus niger family 1 pectin lyase A

    NARCIS (Netherlands)

    Sanchez-Torres, P.; Visser, J.; Benen, J.A.E.

    2003-01-01

    Site-directed-mutagenesis studies were performed on family 1 pectin lyase A (PL1A) from Aspergillus niger to gain insight into the reaction mechanism for the pectin lyase-catalysed beta-elimination cleavage of methylesterified polygalacturonic acid and to stabilize the enzyme at slightly basic pH.

  3. Alginate lyases from alginate-degrading Vibrio splendidus 12B01 are endolytic.

    Science.gov (United States)

    Badur, Ahmet H; Jagtap, Sujit Sadashiv; Yalamanchili, Geethika; Lee, Jung-Kul; Zhao, Huimin; Rao, Christopher V

    2015-03-01

    Alginate lyases are enzymes that degrade alginate through β-elimination of the glycosidic bond into smaller oligomers. We investigated the alginate lyases from Vibrio splendidus 12B01, a marine bacterioplankton species that can grow on alginate as its sole carbon source. We identified, purified, and characterized four polysaccharide lyase family 7 alginates lyases, AlyA, AlyB, AlyD, and AlyE, from V. splendidus 12B01. The four lyases were found to have optimal activity between pH 7.5 and 8.5 and at 20 to 25°C, consistent with their use in a marine environment. AlyA, AlyB, AlyD, and AlyE were found to exhibit a turnover number (kcat) for alginate of 0.60 ± 0.02 s(-1), 3.7 ± 0.3 s(-1), 4.5 ± 0.5 s(-1), and 7.1 ± 0.2 s(-1), respectively. The Km values of AlyA, AlyB, AlyD, and AlyE toward alginate were 36 ± 7 μM, 22 ± 5 μM, 60 ± 2 μM, and 123 ± 6 μM, respectively. AlyA and AlyB were found principally to cleave the β-1,4 bonds between β-d-mannuronate and α-l-guluronate and subunits; AlyD and AlyE were found to principally cleave the α-1,4 bonds involving α-l-guluronate subunits. The four alginate lyases degrade alginate into longer chains of oligomers.

  4. Gene deletion strategy to examine the involvement of the two chondroitin lyases in Flavobacterium columnare virulence.

    Science.gov (United States)

    Li, Nan; Qin, Ting; Zhang, Xiao Lin; Huang, Bei; Liu, Zhi Xin; Xie, Hai Xia; Zhang, Jin; McBride, Mark J; Nie, Pin

    2015-11-01

    Flavobacterium columnare is an important bacterial pathogen of freshwater fish that causes high mortality of infected fish and heavy economic losses in aquaculture. The pathogenesis of this bacterium is poorly understood, in part due to the lack of efficient methods for genetic manipulation. In this study, a gene deletion strategy was developed and used to determine the relationship between the production of chondroitin lyases and virulence. The F. johnsoniae ompA promoter (PompA) was fused to sacB to construct a counterselectable marker for F. columnare. F. columnare carrying PompA-sacB failed to grow on media containing 10% sucrose. A suicide vector carrying PompA-sacB was constructed, and a gene deletion strategy was developed. Using this approach, the chondroitin lyase-encoding genes, cslA and cslB, were deleted. The ΔcslA and ΔcslB mutants were both partially deficient in digestion of chondroitin sulfate A, whereas a double mutant (ΔcslA ΔcslB) was completely deficient in chondroitin lyase activity. Cells of F. columnare wild-type strain G4 and of the chondroitin lyase-deficient ΔcslA ΔcslB mutant exhibited similar levels of virulence toward grass carp in single-strain infections. Coinfections, however, revealed a competitive advantage for the wild type over the chondroitin lyase mutant. The results indicate that chondroitin lyases are not essential virulence factors of F. columnare but may contribute to the ability of the pathogen to compete and cause disease in natural infections. The gene deletion method developed in this study may be employed to investigate the virulence factors of this bacterium and may have wide application in many other members of the phylum Bacteroidetes.

  5. Alginate Lyases from Alginate-Degrading Vibrio splendidus 12B01 Are Endolytic

    Science.gov (United States)

    Badur, Ahmet H.; Jagtap, Sujit Sadashiv; Yalamanchili, Geethika; Lee, Jung-Kul; Zhao, Huimin

    2015-01-01

    Alginate lyases are enzymes that degrade alginate through β-elimination of the glycosidic bond into smaller oligomers. We investigated the alginate lyases from Vibrio splendidus 12B01, a marine bacterioplankton species that can grow on alginate as its sole carbon source. We identified, purified, and characterized four polysaccharide lyase family 7 alginates lyases, AlyA, AlyB, AlyD, and AlyE, from V. splendidus 12B01. The four lyases were found to have optimal activity between pH 7.5 and 8.5 and at 20 to 25°C, consistent with their use in a marine environment. AlyA, AlyB, AlyD, and AlyE were found to exhibit a turnover number (kcat) for alginate of 0.60 ± 0.02 s−1, 3.7 ± 0.3 s−1, 4.5 ± 0.5 s−1, and 7.1 ± 0.2 s−1, respectively. The Km values of AlyA, AlyB, AlyD, and AlyE toward alginate were 36 ± 7 μM, 22 ± 5 μM, 60 ± 2 μM, and 123 ± 6 μM, respectively. AlyA and AlyB were found principally to cleave the β-1,4 bonds between β-d-mannuronate and α-l-guluronate and subunits; AlyD and AlyE were found to principally cleave the α-1,4 bonds involving α-l-guluronate subunits. The four alginate lyases degrade alginate into longer chains of oligomers. PMID:25556193

  6. Mechanism of Hg-C Protonolysis in the Organomercurial Lyase MerB

    Energy Technology Data Exchange (ETDEWEB)

    Parks, Jerry M [ORNL; Guo, Hong [ORNL; Liang, Liyuan [ORNL; Miller, Susan M [ORNL; Summers, Anne O [ORNL; Smith, Jeremy C [ORNL

    2009-01-01

    Demethylation is a key reaction in global mercury cycling. The bacterial organomercurial lyase, MerB, catalyzes the demethylation of a wide range of organomercurials via Hg-C protonolysis. Two strictly conserved cysteine residues in the active site are required for catalysis, but the source of the catalytic proton and the detailed reaction mechanism have not been determined. Here, the two major proposed reaction mechanisms of MerB are investigated and compared using hybrid density functional theory calculations. A model of the active site was constructed from an X-ray crystal structure of the Hg(II)-bound MerB product complex. Stationary point structures and energies characterized for the Hg-C protonolysis of methylmercury rule out the direct protonation mechanism in which a cysteine residue delivers the catalytic proton directly to the organic leaving group. Instead, the calculations support a two-step mechanism in which Cys96 or Cys159 first donates a proton to Asp99, enabling coordination of two thiolates with R-Hg(II). At the rate-limiting transition state, Asp99 protonates the nascent carbanion in a trigonal planar, bis thiol-ligated R-Hg(II) species to cleave the Hg-C bond and release the hydrocarbon product. Reactions with two other substrates, vinylmercury and cis-2-butenyl-2-mercury, were also modeled, and the computed activation barriers for all three organomercurial substrates reproduce the trend in the experimentally observed enzymatic reaction rates. Analysis of atomic charges in the rate-limiting transition state structure using Natural Population Analysis shows that MerB lowers the activation free energy in the Hg-C protonolysis reaction by redistributing electron density into the leaving group and away from the catalytic proton.

  7. SGPL1 (sphingosine phosphate lyase 1) modulates neuronal autophagy via phosphatidylethanolamine production.

    Science.gov (United States)

    Mitroi, Daniel N; Karunakaran, Indulekha; Gräler, Markus; Saba, Julie D; Ehninger, Dan; Ledesma, María Dolores; van Echten-Deckert, Gerhild

    2017-05-04

    Macroautophagy/autophagy defects have been identified as critical factors underlying the pathogenesis of neurodegenerative diseases. The roles of the bioactive signaling lipid sphingosine-1-phosphate (S1P) and its catabolic enzyme SGPL1/SPL (sphingosine phosphate lyase 1) in autophagy are increasingly recognized. Here we provide in vitro and in vivo evidence for a previously unidentified route through which SGPL1 modulates autophagy in neurons. SGPL1 cleaves S1P into ethanolamine phosphate, which is directed toward the synthesis of phosphatidylethanolamine (PE) that anchors LC3-I to phagophore membranes in the form of LC3-II. In the brains of SGPL1(fl/fl/Nes) mice with developmental neural specific SGPL1 ablation, we observed significantly reduced PE levels. Accordingly, alterations in basal and stimulated autophagy involving decreased conversion of LC3-I to LC3-II and increased BECN1/Beclin-1 and SQSTM1/p62 levels were apparent. Alterations were also noticed in downstream events of the autophagic-lysosomal pathway such as increased levels of lysosomal markers and aggregate-prone proteins such as APP (amyloid β [A4] precursor protein) and SNCA/α-synuclein. In vivo profound deficits in cognitive skills were observed. Genetic and pharmacological inhibition of SGPL1 in cultured neurons promoted these alterations, whereas addition of PE was sufficient to restore LC3-I to LC3-II conversion, and control levels of SQSTM1, APP and SNCA. Electron and immunofluorescence microscopy showed accumulation of unclosed phagophore-like structures, reduction of autolysosomes and altered distribution of LC3 in SGPL1(fl/fl/Nes) brains. Experiments using EGFP-mRFP-LC3 provided further support for blockage of the autophagic flux at initiation stages upon SGPL1 deficiency due to PE paucity. These results emphasize a formerly overlooked direct role of SGPL1 in neuronal autophagy and assume significance in the context that autophagy modulators hold an enormous therapeutic potential in the

  8. Inhibition of N-acetylneuraminate lyase by N-acetyl-4-oxo-D-neuraminic acid.

    Science.gov (United States)

    Gross, H J; Brossmer, R

    1988-05-09

    We show that the 4-oxo analogue of N-acetyl-D-neuraminic acid strongly inhibits N-acetylneuraminate lyase (NeuAc aldolase, EC 4.1.3.3) from Clostridum perfringens (Ki = 0.025 mM) and Escherichia coli (Ki = 0.15 mM). In each case the inhibition was competitive. N-Acetyl-D-neuraminic acid; N-Acetylneuraminate lyase; N-Acetyl-D-neuraminic acid analog; 5-Acetamido-3,5-dideoxy-beta-D-manno-non-2,4-diulosonic acid; 2-Deoxy-2,3-didehydro-N-acetyl-4-oxo-neuraminic acid; Competitive inhibitor.

  9. Structural Determinants Responsible for Substrate Recognition and Mode of Action in Family 11 Polysaccharide Lyases*

    OpenAIRE

    Ochiai, Akihito; Itoh, Takafumi; Mikami, Bunzo; Hashimoto, Wataru; Murata, Kousaku

    2009-01-01

    A saprophytic Bacillus subtilis secretes two types of rhamnogalacturonan (RG) lyases, endotype YesW and exotype YesX, which are responsible for an initial cleavage of the RG type I (RG-I) region of plant cell wall pectin. Polysaccharide lyase family 11 YesW and YesX with a significant sequence identity (67.8%) cleave glycoside bonds between rhamnose and galacturonic acid residues in RG-I through a β-elimination reaction. Here we show the structural determinants for sub...

  10. Purification and Characterization of Alginate Lyase from Marine Vibrio sp. YWA

    Institute of Scientific and Technical Information of China (English)

    Yuan-Hong WANG; Guang-Li YU; Xin-Min WANG; Zhi-Hua LV; Xia ZHAO; Zhi-Hong WU; Wei-Shang JI

    2006-01-01

    Extracellular alginate lyase secreted by marine Vibrio sp. YWA, isolated from decayed Laminaria japonica, was purified by a combination of ammonium sulfate precipitation and diethylaminoethyl that the molecular mass of alginate lyase was approximately 62.5 kDa, with an optimal pH and temperature at pH 7.0 and 25 ℃C, respectively. Km was e enzyme was enhanced by EDTA and Zn2+, but inhibited by Ba2+.The substrates specificity analysis shows that it was specific for hydrolyzing poly-β-D-1,4-mannuronate in alginate

  11. A rapid, sensitive, simple plate assay for detection of microbial alginate lyase activity.

    Science.gov (United States)

    Sawant, Shailesh S; Salunke, Bipinchandra K; Kim, Beom Soo

    2015-09-01

    Screening of microorganisms capable of producing alginate lyase enzyme is commonly carried out by investigating their abilities to grow on alginate-containing solid media plates and occurrence of a clearance zone after flooding the plates with agents such as 10% (w/v) cetyl pyridinium chloride (CPC), which can form complexes with alginate. Although the CPC method is good, advantageous, and routinely used, the agar in the media interferes with the action of CPC, which makes judgment about clearance zones very difficult. In addition, this method takes a minimum of 30 min to obtain the zone of hydrolysis after flooding and the hydrolyzed area is not sharply discernible. An improved plate assay is reported herein for the detection of extracellular alginate lyase production by microorganisms. In this method, alginate-containing agar plates are flooded with Gram's iodine instead of CPC. Gram's iodine forms a bluish black complex with alginate but not with hydrolyzed alginate, giving sharp, distinct zones around the alginate lyase producing microbial colonies within 2-3 min. Gram's iodine method was found to be more effective than the CPC method in terms of visualization and measurement of zone size. The alginate-lyase-activity area indicated using the Gram's iodine method was found to be larger than that indicated by the CPC method. Both methods (CPC and Gram's iodine) showed the largest alginate lyase activity area for Saccharophagus degradans (ATCC 43961) followed by Microbulbifer mangrovi (KCTC 23483), Bacillus cereus (KF801505) and Paracoccus sp. LL1 (KP288668) grown on minimal sea salt medium. The rate of growth and metabolite production in alginate-containing minimal sea salt liquid medium, followed trends similar to that of the zone activity areas for the four bacteria under study. These results suggested that the assay developed in this study of Gram's iodine could be useful to predict the potential of microorganisms to produce alginate lyase. The method also

  12. A Study on the Model for Resources Matching of Electronic Bartering%电子易货资源匹配模型研究

    Institute of Scientific and Technical Information of China (English)

    吴剑云; 张嵩

    2012-01-01

    By exchanging idle goods and services, electronic bartering can help enterprises solve dull sale problems, shortage of funds, overstocks and other problems without sufficient cash. Relying on the Internet and the e-commerce platform, electronic bartering removes the traditional bartering limitations, greatly expands the trading object and range, improves the transaction efficiency, and provides additional channels for economic development. How to promote more successful barters among multiple barterers? A key factor is the matching of barter resources. Focusing on the automatic matching of resources in the electronic barter, this paper proposes a network model to help maximize resources matching and provide recommendation information for barter participants, thereby raising the transaction rate and making the barter market prosperous.According to the type and quantity of barter resources, barter market can be divided into two types. In the first type, the supply and demand of the barter market is related to the same type of resources and each barterer owns only one type of resource. In the second type, the supply and demand of the barter market is linked to many types of resources and each barterer owns multiple resources to be exchanged. The first case has been resolved in the relevant document by using the graph theory to solve digraph circuits. This paper is interested in studying the second type of barter. Suppose the barter market has m barterers and n resources. Each barterer owns diverse types of barter resources, and is interested in other types of resources. The barterer a will provide other barterers his own resources only if he gets the resources he needs from the barterer b. Note that each of the bartered resource is regarded as having equal value to any other resources. The main objective is to maximize the number of resources that are bartered.Next, this paper proposes a math model of automatic resources matching by systematically analyzing resource

  13. Kinetic characterization of the human O-phosphoethanolamine phospho-lyase reveals unconventional features of this specialized pyridoxal phosphate-dependent lyase.

    Science.gov (United States)

    Schiroli, Davide; Ronda, Luca; Peracchi, Alessio

    2015-01-01

    Human O-phosphoethanolamine (PEA) phospho-lyase is a pyridoxal 5'-phosphate (PLP) dependent enzyme that catalyzes the degradation of PEA to acetaldehyde, phosphate and ammonia. Physiologically, the enzyme is involved in phospholipid metabolism and is expressed mainly in the brain, where its expression becomes dysregulated in the course of neuropsychiatric diseases. Mechanistically, PEA phospho-lyase shows a remarkable substrate selectivity, strongly discriminating against other amino compounds structurally similar to PEA. Herein, we studied the enzyme under steady-state and pre-steady-state conditions, analyzing its kinetic features and getting insights into the factors that contribute to its specificity. The pH dependence of the catalytic parameters and the pattern of inhibition by the product phosphate and by other anionic compounds suggest that the active site of PEA phospho-lyase is optimized to bind dianionic groups and that this is a prime determinant of the enzyme specificity towards PEA. Single- and multiple-wavelength stopped-flow studies show that upon reaction with PEA the main absorption band of PLP (λmax  = 412 nm) rapidly blue-shifts to ~ 400 nm. Further experiments suggest that the newly formed and rather stable 400-nm species most probably represents a Michaelis (noncovalent) complex of PEA with the enzyme. Accumulation of such an early intermediate during turnover is unusual for PLP-dependent enzymes and appears counterproductive for absolute catalytic performance, but it can contribute to optimize substrate specificity. PEA phospho-lyase may hence represent a case of selectivity-efficiency tradeoff. In turn, the strict specificity of the enzyme seems important to prevent inactivation by other amines, structurally resembling PEA, that occur in the brain. © 2014 FEBS.

  14. Reduced phenylalanine ammonia-lyase and tyrosine ammonia-lyase activities and lignin synthesis in wheat grown under low pressure sodium lamps

    Science.gov (United States)

    Guerra, D.; Anderson, A. J.; Salisbury, F. B.

    1985-01-01

    Wheat (Triticum aestivum L. cv Fremont) grown in hydroponic culture under 24-hour continuous irradiation at 560 to 580 micromoles per square meter per second from either metalhalide (MH), high pressure sodium (HPS), or low pressure sodium (LPS) lamps reached maturity in 70 days. Grain yields were similar under all three lamps, although LPS-grown plants lodged at maturity. Phenylalanine ammonia-lyase (PAL) and a tyrosine ammonia lyase (TAL) with lesser activity were detected in all extracts of leaf, inflorescence, and stem. Ammonia-lyase activities increased with age of the plant, and plants grown under the LPS lamp displayed PAL and TAL activities lower than wheat cultured under MH and HPS radiation. Greenhouse solar-grown wheat had the highest PAL and TAL activities. Lignin content of LPS-grown wheat was also significantly reduced from that of plants grown under MH or HPS lamps or in the greenhouse, showing a correlation with the reduced PAL and TAL activities. Ratios of far red-absorbing phytochrome to total phytochrome were similar for all three lamps, but the data do not yet warrant a conclusion about specific wavelengths missing from the LPS lamps that might have induced PAL and TAL activities in plants under the other lamps.

  15. The Use and Maintenance of University Library Electronic Resources%浅议大学图书馆电子资源的利用与维护

    Institute of Scientific and Technical Information of China (English)

    马鹏飞; 熊豫玲

    2011-01-01

    随着科学技术的飞速发展,高新信息技术的广泛应用,大学图书馆的工作内容和方法也面临新的挑战,为了使用户更好的利用大学图书馆的电子资源,提高电子资源利用率,实现大学图书馆数字化,本文主要从电子资源的利用和维护方面进行探讨。%With the rapid development of science and technology,the extensive application of high-tech information technology, University of content and methods of library work is also facing new challenges in order to make better use of university library users to electronic resources,improve the utilization of electronic resources to achieve the University Library digital,paper, from the use of electronic resources and maintenance were discussed.

  16. Activity and Enantioselectivity of the Hydroxynitrile Lyase MeHNL in Dry Organic Solvents

    NARCIS (Netherlands)

    Hanefeld, U.; Paravidino, M.; Sorgedrager, M.; Orru, R.V.A.

    2010-01-01

    Water concentration affects both the enantioselectivity and activity of enzymes in dry organic media. Its influence has been investigated using the hydrocyanation of benzaldehyde catalyzed by hydroxynitrile lyase cross-linked enzyme aggregate (MeHNL-CLEA) as a model reaction. The enzyme displayed hi

  17. Volatile sulphur compounds-forming abilities of lactic acid bacteria: C-S lyase activities.

    Science.gov (United States)

    Bustos, Irene; Martínez-Bartolomé, Miguel A; Achemchem, Fouad; Peláez, Carmen; Requena, Teresa; Martínez-Cuesta, M Carmen

    2011-08-01

    Volatile sulphur compounds (VSCs) are of prime importance in the overall aroma of cheese and make a significant contribution to their typical flavours. Thus, the control of VSCs formation offers considerable potential for industrial applications. Here, lactic acid bacteria (LAB) from different ecological origins were screened for their abilities to produce VSCs from L-methionine. From the data presented, VSC-forming abilities were shown to be strain-specific and were correlated with the C-S lyase enzymatic activities determined using different approaches. High VSCs formation were detected for those strains that were also shown to possess high thiol-producing abilities (determined either by agar plate or spectrophotometry assays). Moreover, differences in C-S lyase activities were shown to correspond with the enzymatic potential of the strains as determined by in situ gel visualization. Therefore, the assessment of the C-S lyase enzymatic potential, by means of either of these techniques, could be used as a valuable approach for the selection of LAB strains with high VSC-producing abilities thus, representing an effective way to enhance cheese sulphur aroma compounds synthesis. In this regard, this study highlights the flavour forming potential of the Streptococcus thermophilus STY-31, that therefore could be used as a starter culture in cheese manufacture. Furthermore, although C-S lyases are involved in both biosynthetic and catabolic pathways, an association between methionine and cysteine auxotrophy of the selected strains and their VSCs-producing abilities could not be found.

  18. Biochemical and structural characterization of a novel bacterial manganese-dependent hydroxynitrile lyase.

    NARCIS (Netherlands)

    Hajnal, I.; Lyskowski, A.; Hanefeld, U.; Gruber, K.; Schwab, H.; Steiner, K.

    2013-01-01

    Hydroxynitrile lyases (HNLs), which catalyse the decomposition of cyanohydrins, are found mainly in plants. In vitro, they are able to catalyse the synthesis of enantiopure cyanohydrins, which are versatile building blocks in the chemical industry. Recently, HNLs have also been discovered in bacteri

  19. Metabolism of β-valine via a CoA-dependent ammonia lyase pathway

    NARCIS (Netherlands)

    Otzen, Marleen; Crismaru, Ciprian G.; Postema, Christiaan P.; Wijma, Hein J.; Heberling, Matthew M.; Szymanski, Wiktor; de Wildeman, Stefaan; Janssen, Dick B.

    2015-01-01

    Pseudomonas species strain SBV1 can rapidly grow on medium containing β-valine as a sole nitrogen source. The tertiary amine feature of β-valine prevents direct deamination reactions catalyzed by aminotransferases, amino acid dehydrogenases, and amino acid oxidases. However, lyase- or aminomutase-me

  20. Purification and characterization of alginate lyase from locally isolated marine Pseudomonas stutzeri MSEA04.

    Science.gov (United States)

    Beltagy, Ehab A; El-Borai, Aliaa; Lewiz, Marina; ElAssar, Samy A

    2016-09-01

    An alginate lyase with high specific enzyme activity was purified from Pseudomonas stutzeri MSEA04, isolated from marine brown algae. The alginate lyase was purified by precipitation with ammonium sulphate, acetone and ethanol individually. 70% ethanol fraction showed maximum specific activity (133.3 U/mg). This fraction was re-purified by anion exchange chromatography DEAE- Cellulose A-52. The loaded protein was separated into 3 peaks. The second protein peak was the major one which contained 48.2% of the total protein recovered and 79.4% of the total recovered activity. The collected fractions of this peak were subjected to further purification by re-chromatography on Sephadex G-100. Alginate lyase activity was fractionated in the Sephadex column into one major peak, and the specific activity of this fraction reached 116 U/mg. The optimal substrate concentration, pH and temperature for alginate lyase activity were 8 mg/ml, pH 7.5 and 37 °C, respectively. While, Km and Vmax values were 1.07 mg alginate/ ml and 128.2 U/mg protein, respectively. The enzyme was partially stable below 50 °C, and the activity of the enzyme was strongly enhanced by K(+), and strongly inhibited by Ba(+2), Cd(+2), Fe(+2) and Zn(+2). The purified enzyme yielded a single band on SDS-PAGE with molecular weight (40.0 kDa).

  1. The roles of active site residues in the catalytic mechanism of methylaspartate ammonia-lyase

    NARCIS (Netherlands)

    Raj, Hans; Poelarends, Gerrit J

    2013-01-01

    Methylaspartate ammonia-lyase (MAL; EC 4.3.1.2) catalyzes the reversible addition of ammonia to mesaconate to yield l-threo-(2S,3S)-3-methylaspartate and l-erythro-(2S,3R)-3-methylaspartate as products. In the proposed minimal mechanism for MAL of Clostridium tetanomorphum, Lys-331 acts as the (S)-s

  2. Alteration of the Diastereoselectivity of 3-Methylaspartate Ammonia Lyase by Using Structure-Based Mutagenesis

    NARCIS (Netherlands)

    Raj, Hans; Weiner, Barbara; Puthan Veetil, Vinod; Reis, Carlos R.; Quax, Wim J.; Janssen, Dick B.; Feringa, Ben L.; Poelarends, Gerrit J.

    2009-01-01

    3-Methylaspartate ammonia-lyase (MAL) catalyzes the reversible amination of mesaconate to give both (2S,3S)-3-methylaspartic acid and (2S,3R)-3-methylaspartic acid as products. The deamination mechanism of MAL is likely to involve general base catalysis, in which a catalytic base abstracts the C3 pr

  3. Crystal structure and characterization of a novel L-serine ammonia-lyase from Rhizomucor miehei.

    Science.gov (United States)

    Qin, Zhen; Yan, Qiaojuan; Ma, Qingjun; Jiang, Zhengqiang

    2015-10-23

    L-serine ammonia-lyase, as a member of the β-family of pyridoxal-5'-phosphate (PLP) dependent enzymes, catalyzes the conversion of L-serine (L-threonine) to pyruvate (α-ketobutyrate) and ammonia. The crystal structure of L-serine ammonia-lyase from Rhizomucor miehei (RmSDH) was solved at 1.76 Å resolution by X-ray diffraction method. The overall structure of RmSDH had the characteristic β-family PLP dependent enzyme fold. It consisted of two distinct domains, both of which show the typical open twisted α/β structure. A PLP cofactor was located in the crevice between the two domains, which was attached to Lys52 by a Schiff-base linkage. Unique residue substitutions (Gly78, Pro79, Ser146, Ser147 and Thr312) were discovered at the catalytic site of RmSDH by comparison of structures of RmSDH and other reported eukaryotic L-serine ammonia-lyases. Optimal pH and temperature of the purified RmSDH were 7.5 and 40 °C, respectively. It was stable in the pH range of 7.0-9.0 and at temperatures below 40 °C. This is the first crystal structure of a fungal L-serine ammonia-lyase. It will be useful to study the catalytic mechanism of β-elimination enzymes and will provide a basis for further enzyme engineering.

  4. Overexpression of the plg1 gene encoding pectin lyase in Penicillium griseoroseum.

    Science.gov (United States)

    Cardoso, Patrícia Gomes; Ribeiro, João Batista; Teixeira, Janaina Aparecida; de Queiroz, Marisa Vieira; de Araújo, Elza Fernandes

    2008-03-01

    The pectin lyase (PL) is an industrially important enzyme since it is used for maceration and clarification in the process of fruit juice production in food industries. In order to increase the yields of pectin lyase we cloned the plg1 (pectin lyase 1) from Penicillium griseoroseum gene under the control of the strong constitutive promoter of the glyceraldehyde-3-phosphate dehydrogenase gene (gpdA) and the terminator region of the tryptophan synthetase (trpC) gene from Aspergillus nidulans (plasmid pAN52-Plg1) and transformed this construct into the P. griseoroseum strain PG63. One of the pAN52-Plg1 multi-copy transformants (strain 105) grown in culture medium containing glucose or sugar cane juice showed PL activities of 4,804 or 5,202 U ml(-1) respectively, which represented 57- and 132-fold increases. In addition, the apparent specific activity of PL produced by this strain was much higher than the one observed for a commercial pectinase preparation. Evaluation of the extracellular proteins in the culture supernatant of strain 105 by SDS-PAGE showed the presence of a clear and strong band of approximately 40 kDa that probably corresponds to PL. The enzyme yields reported here demonstrate that the system we developed is able to express pectin lyase at levels comparable to, or exceeding, previously reported data.

  5. Activity and Enantioselectivity of the Hydroxynitrile Lyase MeHNL in Dry Organic Solvents

    NARCIS (Netherlands)

    Hanefeld, U.; Paravidino, M.; Sorgedrager, M.; Orru, R.V.A.

    2010-01-01

    Water concentration affects both the enantioselectivity and activity of enzymes in dry organic media. Its influence has been investigated using the hydrocyanation of benzaldehyde catalyzed by hydroxynitrile lyase cross-linked enzyme aggregate (MeHNL-CLEA) as a model reaction. The enzyme displayed

  6. Characterization of the N-linked glycosylation site of recombinant pectate lyase

    NARCIS (Netherlands)

    Colangelo, J.; Licon, V.; Benen, J.A.E.; Visser, J.; Bergmann, C.; Orlando, R.

    1999-01-01

    Recombinant pectate lyase from Aspergillus niger was overexpressed in Aspergillus nidulans. The two recombinant proteins produced differed in molecular mass by 1200 Da, which suggested that the larger molecular weight protein was glycosylated. The deduced amino acid sequence was searched for potenti

  7. Sugar- and nitrogen-dependent regulation of an Amanita muscaria phenylalanine ammonium lyase gene.

    Science.gov (United States)

    Nehls, U; Ecke, M; Hampp, R

    1999-03-01

    The cDNA of a key enzyme of secondary metabolism, phenylalanine ammonium lyase, was identified for an ectomycorrhizal fungus by differential screening of a mycorrhizal library. The gene was highly expressed in hyphae grown at low external monosaccharide concentrations, but its expression was 30-fold reduced at elevated concentrations. Gene repression was regulated by hexokinase.

  8. Production of Alginate Oligosaccharides (AOS as Prebiotic Ingredients through by Alginate lyase enzyme

    Directory of Open Access Journals (Sweden)

    Fahriza Sri Afni

    2017-04-01

    Full Text Available Prebiotics is indigestible foods that can not be digested but can stimulate the growth and activity of bacteria in the digestive tract effecting human health. Alginate oligosaccharides (AOS can be used as a source of prebiotic. That compounds can be produced enzymatically by cutting long chain alginates using alginate lyase. The aim of this study was to produce alginate lyase enzyme then producing Alginate oligosaccharides (AOS as a prebiotic ingredients. The alginate lyase enzyme can be produced from Bacillus megaterium bacteria using a discontinuous fermentor. The enzyme was  optimum temperature of 45°C and an optimum pH of 7.0. Alginate oligosaccharides production was performed with the addition of different enzyme concentrations 25, 50, 75, and 100 U. The result of the addition of enzyme (25, 50,75 U showed that the value of polymerization degrees (DP were between 4-5. However, the addition of enzyme (100 U was in the range of  DP 3-4. Bacterial probiotic growth test results of Bifidobacteria and Lactobacillus showed that 1% added AOS media were able to increase the growth of probiotic bacteria compared to themedia without addition of AOS. The addition Alginate lyase activity of 50 U in AOS production is the best treatment of both probiotic bacteria.

  9. Activity and Enantioselectivity of the Hydroxynitrile Lyase MeHNL in Dry Organic Solvents

    NARCIS (Netherlands)

    Hanefeld, U.; Paravidino, M.; Sorgedrager, M.; Orru, R.V.A.

    2010-01-01

    Water concentration affects both the enantioselectivity and activity of enzymes in dry organic media. Its influence has been investigated using the hydrocyanation of benzaldehyde catalyzed by hydroxynitrile lyase cross-linked enzyme aggregate (MeHNL-CLEA) as a model reaction. The enzyme displayed hi

  10. Hematopoietic sphingosine 1-phosphate lyase deficiency decreases atherosclerotic lesion development in LDL-receptor deficient mice.

    Directory of Open Access Journals (Sweden)

    Martine Bot

    Full Text Available AIMS: Altered sphingosine 1-phosphate (S1P homeostasis and signaling is implicated in various inflammatory diseases including atherosclerosis. As S1P levels are tightly controlled by S1P lyase, we investigated the impact of hematopoietic S1P lyase (Sgpl1(-/- deficiency on leukocyte subsets relevant to atherosclerosis. METHODS AND RESULTS: LDL receptor deficient mice that were transplanted with Sgpl1(-/- bone marrow showed disrupted S1P gradients translating into lymphopenia and abrogated lymphocyte mitogenic and cytokine response as compared to controls. Remarkably however, Sgpl1(-/- chimeras displayed mild monocytosis, due to impeded stromal retention and myelopoiesis, and plasma cytokine and macrophage expression patterns, that were largely compatible with classical macrophage activation. Collectively these two phenotypic features of Sgpl1 deficiency culminated in diminished atherogenic response. CONCLUSIONS: Here we not only firmly establish the critical role of hematopoietic S1P lyase in controlling S1P levels and T cell trafficking in blood and lymphoid tissue, but also identify leukocyte Sgpl1 as critical factor in monocyte macrophage differentiation and function. Its, partly counterbalancing, pro- and anti-inflammatory activity spectrum imply that intervention in S1P lyase function in inflammatory disorders such as atherosclerosis should be considered with caution.

  11. Structural basis for the entrance into the phenylpropanoid metabolism catalyzed by phenylalanine ammonia-lyase.

    Science.gov (United States)

    Ritter, Holger; Schulz, Georg E

    2004-12-01

    Because of its key role in secondary phenylpropanoid metabolism, Phe ammonia-lyase is one of the most extensively studied plant enzymes. To provide a basis for detailed structure-function studies, the enzyme from parsley (Petroselinum crispum) was crystallized, and the structure was elucidated at 1.7-A resolution. It contains the unusual electrophilic 4-methylidene-imidazole-5-one group, which is derived from a tripeptide segment in two autocatalytic dehydration reactions. The enzyme resembles His ammonia-lyase from the general His degradation pathway but contains 207 additional residues, mainly in an N-terminal extension rigidifying a domain interface and in an inserted alpha-helical domain restricting the access to the active center. Presumably, Phe ammonia-lyase developed from His ammonia-lyase when fungi and plants diverged from the other kingdoms. A pathway of the catalyzed reaction is proposed in agreement with established biochemical data. The inactivation of the enzyme by a nucleophile is described in detail.

  12. Diversity of RuBisCO and ATP citrate lyase genes in soda lake sediments

    NARCIS (Netherlands)

    Kovaleva, O.L.; Tourova, T.P.; Muyzer, G.; Kolganova, T.V.; Sorokin, D.Y.

    2011-01-01

    Sediments from six soda lakes of the Kulunda Steppe (Altai, Russia) and from hypersaline alkaline lakes of Wadi Natrun (Egypt) were analyzed for the presence of cbb and aclB genes encoding key enzymes Ci assimilation (RuBisCO in Calvin-Benson and ATP citrate lyase in rTCA cycles, respectively). The

  13. Structural (betaalpha)8 TIM barrel model of 3-hydroxy-3-methylglutaryl-coenzyme A lyase.

    Science.gov (United States)

    Casals, Núria; Gómez-Puertas, Paulino; Pié, Juan; Mir, Cecilia; Roca, Ramón; Puisac, Beatriz; Aledo, Rosa; Clotet, Josep; Menao, Sebastián; Serra, Dolors; Asins, Guillermina; Till, Jacqueline; Elias-Jones, Alun C; Cresto, Juan C; Chamoles, Nestor A; Abdenur, Jose E; Mayatepek, Ertan; Besley, Guy; Valencia, Alfonso; Hegardt, Fausto G

    2003-08-01

    This study describes three novel homozygous missense mutations (S75R, S201Y, and D204N) in the 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) lyase gene, which caused 3-hydroxy-3-methylglutaric aciduria in patients from Germany, England, and Argentina. Expression studies in Escherichia coli show that S75R and S201Y substitutions completely abolished the HMG-CoA lyase activity, whereas D204N reduced catalytic efficiency to 6.6% of the wild type. We also propose a three-dimensional model for human HMG-CoA lyase containing a (betaalpha)8 (TIM) barrel structure. The model is supported by the similarity with analogous TIM barrel structures of functionally related proteins, by the localization of catalytic amino acids at the active site, and by the coincidence between the shape of the substrate (HMG-CoA) and the predicted inner cavity. The three novel mutations explain the lack of HMG-CoA lyase activity on the basis of the proposed structure: in S75R and S201Y because the new amino acid residues occlude the substrate cavity, and in D204N because the mutation alters the electrochemical environment of the active site. We also report the localization of all missense mutations reported to date and show that these mutations are located in the beta-sheets around the substrate cavity.

  14. Cloning and characterization of a novel oligoalginate lyase from a newly isolated bacterium Sphingomonas sp. MJ-3.

    Science.gov (United States)

    Park, Hwan Hee; Kam, Natania; Lee, Eun Yeol; Kim, Hee Sook

    2012-04-01

    A bacterium possessing alginate-degrading activity was isolated from marine brown seaweed soup liquefied by salted and fermented anchovy. The isolated strain was designated as Sphingomonas sp. MJ-3 based on the analyses of 16S ribosomal DNA sequences, 16S-23S internal transcribed spacer region sequences, biochemical characteristics, and cellular fatty acid composition. A novel alginate lyase gene was cloned from genomic DNA library and then expressed in Escherichia coli. When the deduced amino acid sequence was compared with the sequences on the databases, interestingly, the cloned gene product was predicted to consist of AlgL (alginate lyase L)-like and heparinase-like protein domain. The MJ-3 alginate lyase gene shared below 27.0% sequence identity with exolytic alginate lyase of Sphingomonas sp. A1. The optimal pH and temperature for the recombinant MJ-3 alginate lyase were 6.5 and 50°C, respectively. The final degradation products of alginate oligosaccharides were analyzed by electrospray ionization mass spectrometry and proved to be alginate monosaccharides. Based on the results, the recombinant alginate lyase from Sphingomonas sp. MJ-3 is regarded as an oligoalginate lyase that can degrade oligoalginate and alginate into alginate monosaccharides.

  15. Barriers to electronic access and delivery of educational information in resource constrained public schools: a case of Greater Tubatse Municipality

    CSIR Research Space (South Africa)

    Pholotho, T

    2016-05-01

    Full Text Available Information and Communication Technologies (ICTs) are capable of expanding access to quality education, educational resources and provide teachers with new skills. Nevertheless, a majority of rural public schools have limited ICTs, mainly due...

  16. Electronic Grey Literature in Accelerator Science and Its Allied Subjects : Selected Web Resources for Scientists and Engineers

    CERN Document Server

    Rajendiran, P

    2006-01-01

    Grey literature Web resources in the field of accelerator science and its allied subjects are collected for the scientists and engineers of RRCAT (Raja Ramanna Centre for Advanced Technology). For definition purposes the different types of grey literature are described. The Web resources collected and compiled in this article (with an overview and link for each) specifically focus on technical reports, preprints or e-prints, which meet the main information needs of RRCAT users.

  17. Pectate lyase pollen allergens: sensitization profiles and cross-reactivity pattern.

    Directory of Open Access Journals (Sweden)

    Ulrike Pichler

    Full Text Available Pollen released by allergenic members of the botanically unrelated families of Asteraceae and Cupressaceae represent potent elicitors of respiratory allergies in regions where these plants are present. As main allergen sources the Asteraceae species ragweed and mugwort, as well as the Cupressaceae species, cypress, mountain cedar, and Japanese cedar have been identified. The major allergens of all species belong to the pectate lyase enzyme family. Thus, we thought to investigate cross-reactivity pattern as well as sensitization capacities of pectate lyase pollen allergens in cohorts from distinct geographic regions.The clinically relevant pectate lyase pollen allergens Amb a 1, Art v 6, Cup a 1, Jun a 1, and Cry j 1 were purified from aqueous pollen extracts, and patients' sensitization pattern of cohorts from Austria, Canada, Italy, and Japan were determined by IgE ELISA and cross-inhibition experiments. Moreover, we performed microarray experiments and established a mouse model of sensitization.In ELISA and ELISA inhibition experiments specific sensitization pattern were discovered for each geographic region, which reflected the natural allergen exposure of the patients. We found significant cross-reactivity within Asteraceae and Cupressaceae pectate lyase pollen allergens, which was however limited between the orders. Animal experiments showed that immunization with Asteraceae allergens mainly induced antibodies reactive within the order, the same was observed for the Cupressaceae allergens. Cross-reactivity between orders was minimal. Moreover, Amb a 1, Art v 6, and Cry j 1 showed in general higher immunogenicity.We could cluster pectate lyase allergens in four categories, Amb a 1, Art v 6, Cup a 1/Jun a 1, and Cry j 1, respectively, at which each category has the potential to sensitize predisposed individuals. The sensitization pattern of different cohorts correlated with pollen exposure, which should be considered for future allergy

  18. Crystal structure and characterization of a novel L-serine ammonia-lyase from Rhizomucor miehei

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhen [College of Food Science and Nutritional Engineering, Beijing Advanced Innovation Center of Food Nutrition and Human Health, China Agricultural University, Beijing 100083 (China); Yan, Qiaojuan [College of Engineering, China Agricultural University, Beijing 100083 (China); Ma, Qingjun [Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Jiang, Zhengqiang, E-mail: zhqjiang@cau.edu.cn [College of Food Science and Nutritional Engineering, Beijing Advanced Innovation Center of Food Nutrition and Human Health, China Agricultural University, Beijing 100083 (China)

    2015-10-23

    L-serine ammonia-lyase, as a member of the β-family of pyridoxal-5′-phosphate (PLP) dependent enzymes, catalyzes the conversion of L-serine (L-threonine) to pyruvate (α-ketobutyrate) and ammonia. The crystal structure of L-serine ammonia-lyase from Rhizomucor miehei (RmSDH) was solved at 1.76 Å resolution by X-ray diffraction method. The overall structure of RmSDH had the characteristic β-family PLP dependent enzyme fold. It consisted of two distinct domains, both of which show the typical open twisted α/β structure. A PLP cofactor was located in the crevice between the two domains, which was attached to Lys52 by a Schiff-base linkage. Unique residue substitutions (Gly78, Pro79, Ser146, Ser147 and Thr312) were discovered at the catalytic site of RmSDH by comparison of structures of RmSDH and other reported eukaryotic L-serine ammonia-lyases. Optimal pH and temperature of the purified RmSDH were 7.5 and 40 °C, respectively. It was stable in the pH range of 7.0–9.0 and at temperatures below 40 °C. This is the first crystal structure of a fungal L-serine ammonia-lyase. It will be useful to study the catalytic mechanism of β-elimination enzymes and will provide a basis for further enzyme engineering. - Highlights: • The crystal structure of a fungal L-serine ammonia-lyase (RmSDH) was solved. • Five unique residue substitutions are found at the catalytic site of RmSDH. • RmSDH was expressed in Pichia. pastoris and biochemically characterized. • RmSDH has potential application in splitting D/L-serine.

  19. Purification, characterization and induction of L-phenylalanine ammonia-lyase in Phaseolus vulgaris.

    Science.gov (United States)

    da Cunha, A

    1988-12-01

    The enzyme L-phenylalanine ammonia-lyase was purified from leaves of Phaseolus vulgaris by Sephacryl S-200 gel filtration and Sepharose-4-B--succinyl-aminoethyl-L-phenylalanine affinity chromatography. L-Phenylalanine ammonia-lyase was specifically eluted from the affinity matrix with its substrate L-phenylalanine at 20-25 degrees C. The purified enzyme was shown to be homogeneous by gel electrophoresis both in presence and absence of SDS. Its Mr, determined by gel filtration and non-denaturing gel electrophoresis, was 320,000 +/- 9000 and 330,000 +/- 4000 respectively. After SDS electrophoresis only one band of Mr 83,000 +/- 4000 was detected, indicating that the enzyme is an oligomer containing four subunits. The pH optimum of enzyme activity was 8.8-9.2. Ampholyte isoelectrofocusing in polyacrylamide demonstrated the presence of a single charged species at pH 4.2. The homogeneous enzyme catalyzed the deamination of L-phenylalanine to trans-cinnamate but did not catalyze the transamination of L-phenylalanine to L-phenylpyruvate. The enzyme showed Km 1.25 mM for L-phenylalanine. Antibodies to homogeneous L-phenylalanine ammonia-lyase recognised specific epitopes on L-phenylalanine aminotransferase as demonstrated by immunoaffinity purification and immunoblotting. The induction of L-phenylalanine ammonia-lyase activity during phaseollin biosynthesis in the Phaseolus vulgaris--Colletotrichum lindemuthianum interaction was regulated by an increase in enzyme concentration resulting from an increase in de novo synthesis of L-phenylalanine ammonia-lyase protein.

  20. Electrochemical sensing platform amplified with a nanobiocomposite of L-phenylalanine ammonia-lyase enzyme for the detection of capsaicin.

    Science.gov (United States)

    Sabela, Myalowenkosi I; Mpanza, Thabani; Kanchi, Suvardhan; Sharma, Deepali; Bisetty, Krishna

    2016-09-15

    The present study involves the development of a sensitive electrochemical biosensor for the determination of capsaicin extracted from chilli fruits, based on a novel signal amplification strategy using enzyme technology. For the first time, platinum electrode modified with multiwalled carbon nanotubes where phenylalanine ammonia-lyase enzyme was immobilized using nafion was characterized by attenuated total reflectance infrared spectroscopy, transmittance electron microscopy and thermo-gravimetric analysis supported by computational methods. Cyclic and differential pulse voltammetry measurements were performed to better understand the redox mechanism of capsaicin. The performance of the developed electrochemical biosensor was tested using spiked samples with recoveries ranging from 98.9 to 99.6%. The comparison of the results obtained from bare and modified platinum electrodes revealed the sensitivity of the developed biosensor, having a detection limit (S/N=3) of 0.1863µgmL(-1) and electron transfer rate constant (ks) of 3.02s(-1). Furthermore, adsorption and ligand-enzyme docking studies were carried out to better understand the redox mechanisms supported by density functional theory calculations. These results revealed that capsaicin forms hydrogen bonds with GLU355, GLU541, GLU586, ARG and other amino acids of the hydrophobic channel of the binding sites thereby facilitating the redox reaction for the detection of capsaicin.

  1. The strawberry (Fragariaxananassa) fruit-specific rhamnogalacturonate lyase 1 (FaRGLyase1) gene encodes an enzyme involved in the degradation of cell-wall middle lamellae.

    Science.gov (United States)

    Molina-Hidalgo, Francisco J; Franco, Antonio R; Villatoro, Carmen; Medina-Puche, Laura; Mercado, José A; Hidalgo, Miguel A; Monfort, Amparo; Caballero, José Luis; Muñoz-Blanco, Juan; Blanco-Portales, Rosario

    2013-04-01

    Pectins are essential components of primary plant cell walls and middle lamellae, and are related to the consistency of the fruit and its textural changes during ripening. In fact, strawberries become soft as the middle lamellae of cortical parenchyma cells are extensively degraded during ripening, leading to the observed short post-harvest shelf life. Using a custom-made oligonucleotide-based strawberry microarray platform, a putative rhamnogalacturonate lyase gene (FaRGlyase1) was identified. Bioinformatic analysis of the FaRGlyase1 sequence allowed the identification of a conserved rhamnogalacturonate lyase domain, which was also present in other putative RGlyase sequences deposited in the databases. Expression of FaRGlyase1 occurred mainly in the receptacle, concurrently with ripening, and it was positively regulated by abscisic acid and negatively by auxins. FaRGLyase1 gene expression was transiently silenced by injecting live Agrobacterium cells harbouring RNA interference constructs into fruit receptacles. Light and electron microscopy analyses of these transiently silenced fruits revealed that this gene is involved in the degradation of pectins present in the middle lamella region between parenchymatic cells. In addition, genetic linkage association analyses in a strawberry-segregating population showed that FaRGLyase1 is linked to a quantitative trait loci linkage group related to fruit hardness and firmness. The results showed that FaRGlyase1 could play an important role in the fruit ripening-related softening process that reduces strawberry firmness and post-harvest life.

  2. 电子资源许可使用的发展与创新%The Development and Innovation of the Use of the Electronic Resource License

    Institute of Scientific and Technical Information of China (English)

    王军

    2012-01-01

      电子资源许可使用在我国发展时间较短,在其建立过程中还存在许可定价、购买模式、馆际互借以及电子资源的长期保存许可方式等难题。电子资源许可使用的发展与创新,需要根据用户需求制定发展战略,建立图书馆的读者监督管理制度和数字化资源服务制度,规范文献编目制度等,以提高电子信息资源与图书馆信息资源的使用效果和广泛的使用需求%  It's been a short time since the use of electronic resource licenses has developed in China; in addition, many problems ap-pear in the establishment process in terms of license pricing, purchase pattern, inter-library loan and long-term preservation ways of electronic resources. In order to develop and innovate the use of the license, libraries should develop strategies in accordance with the users' needs, establish a reader supervision system and a digital resource service system, and normalize the document cataloging sys-tem to enhance the utilization effect and meet the extensive demand for electronic and library information resources.

  3. Cysteine Conjugate β-Lyase Activity of Rat Erythrocytes and Formation of β-Lyase-Derived Globin Monoadducts and Cross-Links after in Vitro Exposure of Erythrocytes to S-(1,2-Dichlorovinyl)-L-cysteine

    OpenAIRE

    Barshteyn, Nella; Elfarra, Adnan A.

    2009-01-01

    S-(1,2-Dichlorovinyl)-L-cysteine (DCVC), a mutagenic and nephrotoxic metabolite of trichloroethylene can be bioactivated to reactive metabolites, S-(1,2-dichlorovinyl)-L-cysteine sulfoxide (DCVCS) or chlorothioketene and/or 2-chlorothionoacetyl chloride, by cysteine conjugate S-oxidase (S-oxidase) and cysteine conjugate β-lyase (β-lyase), respectively. Previously, we characterized reactivity of DCVCS with Hb upon incubation of erythrocytes with DCVCS and provided evidence for formation of dis...

  4. Structural and Functional Studies on Salmonella Typhimurium Ethanolamine Ammonia-Lyase

    Science.gov (United States)

    Bovell, Adonis

    Ethanolamine ammonia-lyase (EAL), a coenzyme-B12 (AdoCbl) dependent bacterial enzyme, catalyzes the deamination of select amino-alcohols by using a radical mechanism. Extensive high-resolution spectroscopic determinations of reactant intermediate-state structures and detailed kinetic and thermodynamic studies have been conducted for the Salmonella typhimurium enzyme. A statistically robust homology model for the full [(EutB-EutC) 2]3 oligomer of S. typhimurium EAL is constructed from the Escherichia coli crystal structure. This structure establishes a platform for detailed, microscopic interpretation of the molecular mechanism of EAL catalysis. The model is used to describe the hierarchy of EutB and EutC subunit interactions in the native oligomer and to guide a genetic and biochemical approach to the long-standing challenge of functional oligomer reconstitution from isolated subunits. The model is used to direct site-directed mutagenesis of EAL, leading to the creation of the EutB-F258W mutant, whose fluorescence is sensitive to the binding of AdoCbl. The AdoCbl-EAL dissociation constant is determined to be 1.2 microM, which places limits on the timescale of cofactor exchange kinetics. A series of cysteine-replaced mutants of EAL was created, and progress was made towards the goal of a mutant EAL for site-directed spin labeling studies. The primary cysteine attachment site in wild-type EAL for the 4-maleimido-TEMPO spin label was identified as EutC-C37. The localization of spin labels on EAL enables the interpretation of electron paramagnetic resonance (EPR) studies that probe distal effects on protein structure caused by cofactor binding. Previously determined rate constants for decay of the cryotrapped substrate radical, and kcat values at ambient temperature, for 1H- and 2H-labelled substrate, are united in a single model that describes the sequential radical rearrangement and hydrogen atom transfer steps, from 190 to 295 K. The model indicates that hydrogen

  5. Mechanistic studies of the spore photoproduct lyase via a single cysteine mutation.

    Science.gov (United States)

    Yang, Linlin; Lin, Gengjie; Nelson, Renae S; Jian, Yajun; Telser, Joshua; Li, Lei

    2012-09-11

    5-Thyminyl-5,6-dihydrothymine (also called spore photoproduct or SP) is the exclusive DNA photodamage product in bacterial endospores. It is repaired by a radical SAM (S-adenosylmethionine) enzyme, the spore photoproduct lyase (SPL), at the bacterial early germination phase. Our previous studies proved that SPL utilizes the 5'-dA• generated by the SAM cleavage reaction to abstract the H(6proR) atom to initiate the SP repair process. The resulting thymine allylic radical was suggested to take an H atom from an unknown protein source, most likely cysteine 141. Here we show that C141 can be readily alkylated in the native SPL by an iodoacetamide treatment, suggesting that it is accessible to the TpT radical. SP repair by the SPL C141A mutant yields TpTSO(2)(-) and TpT simultaneously from the very beginning of the reaction; no lag phase is observed for TpTSO(2)(-) formation. Should any other protein residue serve as the H donor, its presence would result in TpT being the major product at least for the first enzyme turnover. These observations provide strong evidence to support C141 as the direct H atom donor. Moreover, because of the lack of this intrinsic H donor, the C141A mutant produces TpT via an unprecedented thymine cation radical reduction (proton-coupled electron transfer) process, contrasting to the H atom transfer mechanism in the wild-type (WT) SPL reaction. The C141A mutant repairs SP at a rate that is ~3-fold slower than that of the WT enzyme. Formation of TpTSO(2)(-) and TpT exhibits a V(max) deuterium kinetic isotope effect (KIE) of 1.7 ± 0.2, which is smaller than the (D)V(max) KIE of 2.8 ± 0.3 determined for the WT SPL reaction. These findings suggest that removing the intrinsic H atom donor disturbs the rate-limiting process during enzyme catalysis. As expected, the prereduced C141A mutant supports only ~0.4 turnover, which is in sharp contrast to the >5 turnovers exhibited by the WT SPL reaction, suggesting that the enzyme catalytic cycle (SAM

  6. Mechanistic studies of the radical SAM enzyme spore photoproduct lyase (SPL).

    Science.gov (United States)

    Li, Lei

    2012-11-01

    Spore photoproduct lyase (SPL) repairs a special thymine dimer 5-thyminyl-5,6-dihydrothymine, which is commonly called spore photoproduct or SP at the bacterial early germination phase. SP is the exclusive DNA photo-damage product in bacterial endospores; its generation and swift repair by SPL are responsible for the spores' extremely high UV resistance. The early in vivo studies suggested that SPL utilizes a direct reversal strategy to repair the SP in the absence of light. The research in the past decade further established SPL as a radical SAM enzyme, which utilizes a tri-cysteine CXXXCXXC motif to harbor a [4Fe-4S] cluster. At the 1+ oxidation state, the cluster provides an electron to the S-adenosylmethionine (SAM), which binds to the cluster in a bidentate manner as the fourth and fifth ligands, to reductively cleave the CS bond associated with the sulfonium ion in SAM, generating a reactive 5'-deoxyadenosyl (5'-dA) radical. This 5'-dA radical abstracts the proR hydrogen atom from the C6 carbon of SP to initiate the repair process; the resulting SP radical subsequently fragments to generate a putative thymine methyl radical, which accepts a back-donated H atom to yield the repaired TpT. SAM is suggested to be regenerated at the end of each catalytic cycle; and only a catalytic amount of SAM is needed in the SPL reaction. The H atom source for the back donation step is suggested to be a cysteine residue (C141 in Bacillus subtilis SPL), and the H-atom transfer reaction leaves a thiyl radical behind on the protein. This thiyl radical thus must participate in the SAM regeneration process; however how the thiyl radical abstracts an H atom from the 5'-dA to regenerate SAM is unknown. This paper reviews and discusses the history and the latest progress in the mechanistic elucidation of SPL. Despite some recent breakthroughs, more questions are raised in the mechanistic understanding of this intriguing DNA repair enzyme. This article is part of a Special Issue

  7. Structural And Biochemical Characterization of the Therapeutic A. Variabilis Phenylalanine Ammonia Lyase

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L.; Gamez, A.; Archer, H.; Abola, E.E.; Sarkissian, C.N.; Fitzpatrick, P.; Wendt, D.; Zhang, Y.; Vellard, M.; Bliesath, J.; Bell, S.; Lemont, J.; Scriver, C.R.; Stevens, R.C.

    2009-05-26

    We have recently observed promising success in a mouse model for treating the metabolic disorder phenylketonuria with phenylalanine ammonia lyase (PAL) from Rhodosporidium toruloides and Anabaena variabilis. Both molecules, however, required further optimization in order to overcome problems with protease susceptibility, thermal stability, and aggregation. Previously, we optimized PAL from R. toruloides, and in this case we reduced aggregation of the A. variabilis PAL by mutating two surface cysteine residues (C503 and C565) to serines. Additionally, we report the structural and biochemical characterization of the A. variabilis PAL C503S/C565S double mutant and carefully compare this molecule with the R. toruloides engineered PAL molecule. Unlike previously published PAL structures, significant electron density is observed for the two active-site loops in the A. variabilis C503S/C565S double mutant, yielding a complete view of the active site. Docking studies and N-hydroxysuccinimide-biotin binding studies support a proposed mechanism in which the amino group of the phenylalanine substrate is attacked directly by the 4-methylidene-imidazole-5-one prosthetic group. We propose a helix-to-loop conformational switch in the helices flanking the inner active-site loop that regulates accessibility of the active site. Differences in loop stability among PAL homologs may explain the observed variation in enzyme efficiency, despite the highly conserved structure of the active site. A. variabilis C503S/C565S PAL is shown to be both more thermally stable and more resistant to proteolytic cleavage than R. toruloides PAL. Additional increases in thermal stability and protease resistance upon ligand binding may be due to enhanced interactions among the residues of the active site, possibly locking the active-site structure in place and stabilizing the tetramer. Examination of the A. variabilis C503S/C565S PAL structure, combined with analysis of its physical properties, provides

  8. SGPL1 (sphingosine phosphate lyase 1) modulates neuronal autophagy via phosphatidylethanolamine production

    Science.gov (United States)

    Mitroi, Daniel N.; Karunakaran, Indulekha; Gräler, Markus; Saba, Julie D.; Ehninger, Dan; Ledesma, María Dolores; van Echten-Deckert, Gerhild

    2017-01-01

    ABSTRACT Macroautophagy/autophagy defects have been identified as critical factors underlying the pathogenesis of neurodegenerative diseases. The roles of the bioactive signaling lipid sphingosine-1-phosphate (S1P) and its catabolic enzyme SGPL1/SPL (sphingosine phosphate lyase 1) in autophagy are increasingly recognized. Here we provide in vitro and in vivo evidence for a previously unidentified route through which SGPL1 modulates autophagy in neurons. SGPL1 cleaves S1P into ethanolamine phosphate, which is directed toward the synthesis of phosphatidylethanolamine (PE) that anchors LC3-I to phagophore membranes in the form of LC3-II. In the brains of SGPL1fl/fl/Nes mice with developmental neural specific SGPL1 ablation, we observed significantly reduced PE levels. Accordingly, alterations in basal and stimulated autophagy involving decreased conversion of LC3-I to LC3-II and increased BECN1/Beclin-1 and SQSTM1/p62 levels were apparent. Alterations were also noticed in downstream events of the autophagic-lysosomal pathway such as increased levels of lysosomal markers and aggregate-prone proteins such as APP (amyloid β [A4] precursor protein) and SNCA/α-synuclein. In vivo profound deficits in cognitive skills were observed. Genetic and pharmacological inhibition of SGPL1 in cultured neurons promoted these alterations, whereas addition of PE was sufficient to restore LC3-I to LC3-II conversion, and control levels of SQSTM1, APP and SNCA. Electron and immunofluorescence microscopy showed accumulation of unclosed phagophore-like structures, reduction of autolysosomes and altered distribution of LC3 in SGPL1fl/fl/Nes brains. Experiments using EGFP-mRFP-LC3 provided further support for blockage of the autophagic flux at initiation stages upon SGPL1 deficiency due to PE paucity. These results emphasize a formerly overlooked direct role of SGPL1 in neuronal autophagy and assume significance in the context that autophagy modulators hold an enormous therapeutic potential

  9. Clinician‐selected Electronic Information Resources do not Guarantee Accuracy in Answering Primary Care Physicians’ Information Needs. A review of: McKibbon, K. Ann, and Douglas B. Fridsma. “Effectiveness of Clinician‐selected Electronic Information Resources for Answering Primary Care Physicians’ Information Needs.” Journal of the American Medical Informatics Association 13.6 (2006: 653‐9.

    Directory of Open Access Journals (Sweden)

    Martha Ingrid Preddie

    2008-03-01

    Full Text Available Objective – To determine if electronic information resources selected by primary care physicians improve their ability to answer simulated clinical questions.Design – An observational study utilizing hour‐long interviews and think‐aloud protocols.Setting – The offices and clinics of primary care physicians in Canada and the United States.Subjects – Twenty‐five primary care physicians of whom 4 were women, 17 were from Canada, 22 were family physicians,and 24 were board certified.Methods – Participants provided responses to 23 multiple‐choice questions. Each physician then chose two questions and looked for the answers utilizing information resources of their own choice. The search processes, chosen resources and search times were noted. These were analyzed along with data on the accuracy of the answers and certainties related to the answer to each clinical question prior to the search.Main results – Twenty‐three physicians sought answers to 46 simulated clinical questions. Utilizing only electronic information resources, physicians spent a mean of 13.0 (SD 5.5 minutes searching for answers to the questions, an average of 7.3(SD 4.0 minutes for the first question and 5.8 (SD 2.2 minutes to answer the second question. On average, 1.8 resources were utilized per question. Resources that summarized information, such as the Cochrane Database of Systematic Reviews, UpToDate and Clinical Evidence, were favored 39.2% of the time, MEDLINE (Ovid and PubMed 35.7%, and Internet resources including Google 22.6%. Almost 50% of the search and retrieval strategies were keyword‐based, while MeSH, subheadings and limiting were used less frequently. On average, before searching physicians answered 10 of 23 (43.5% questions accurately. For questions that were searched using clinician‐selected electronic resources, 18 (39.1% of the 46 answers were accurate before searching, while 19 (42.1% were accurate after searching. The difference of

  10. Conceived on the City Electronic Waste Resource Mana oement Model%城市电子废弃物资源化管理模式构想

    Institute of Scientific and Technical Information of China (English)

    熊贵琍; 余涛

    2012-01-01

    Investigated e- waste collection system the investigation, the whereabouts and electronic waste disposal in Httizhou city, the paper analyzed the Huizhou city e- waste collection and disposal of a series of problems, combined with the actual, conceived urban electronic waste resources management mode.%通过对惠州市电子废弃物收集体系组成、去向以及电子废弃物处置方式的调查,分析惠州市电子废弃物收集和处置存在的一系列问题,结合实际提出了城市电子废弃物资源化管理模式的初步构想。

  11. Characterization of smart auto-degradative hydrogel matrix containing alginate lyase to enhance levofloxacin delivery against bacterial biofilms.

    Science.gov (United States)

    Islan, German A; Dini, Cecilia; Bartel, Laura C; Bolzán, Alejandro D; Castro, Guillermo R

    2015-12-30

    The aim of the present work is the characterization of smart auto-degradable microspheres composed of calcium alginate/high methoxylated pectin containing an alginate lyase (AL) from Sphingobacterium multivorum and levofloxacin. Microspheres were prepared by ionotropic gelation containing AL in its inactive form at pH 4.0. Incubation of microspheres in Tris-HCl and PBS buffers at pH 7.40 allowed to establish the effect of ion-chelating phosphate on matrix erodability and suggested an intrinsically activation of AL by turning the pH close to neutrality. Scanning electron and optical microscopies revealed the presence of holes and surface changes in AL containing microspheres. Furthermore, texturometric parameters, DSC profiles and swelling properties were showing strong changes in microspheres properties. Encapsulation of levofloxacin into microspheres containing AL showed 70% efficiency and 35% enhancement of antimicrobial activity against Pseudomonas aeruginosa biofilm. Levofloxacin release from microspheres was not changed at acidic pH, but was modified at neutral pH in presence of AL. Advantageously, only gel matrix debris were detectable after overnight incubation, indicating an autodegradative gel process activated by the pH. Absence of matrix cytotoxicity and a reduction of the levofloxacin toxicity after encapsulation were observed in mammalian CHO-K1 cell cultures. These properties make the system a potent and versatile tool for antibiotic oral delivery targeted to intestine, enhancing the drug bioavailability to eradicate bacterial biofilm and avoiding possible intestinal obstructions.

  12. Overexpression of isocitrate lyase-glyoxylate bypass influence on metabolism in Aspergillus niger

    DEFF Research Database (Denmark)

    Meijer, Susan Lisette; Otero, José Manuel; Olivares Hernandez, Roberto

    2009-01-01

    glyoxylate would increase, leading to excess formation of malate and succinate compared to the wild-type. However, metabolic network analysis showed that an increased icl expression did not result in an increased glyoxylate bypass flux. The analysis did show a global response with respect to gene expression......In order to improve the production of succinate and malate by the filamentous fungus Aspergillus niger the activity of the glyoxylate bypass pathway was increased by over-expression of the isocitrate lyase (icl) gene. The hypothesis was that when isocitrate lyase was up-regulated the flux towards......, leading to an increased flux through the oxidative part of the TCA cycle. Instead of an increased production of succinate and malate, a major increase in fumarate production was observed. The effect of malonate, a competitive inhibitor of succinate dehydrogenase (SDH), on the physiological behaviour...

  13. Syntheses of L-tyrosine-related amino acids by tyrosine phenol-lyase of Citrobacter intermedius.

    Science.gov (United States)

    Nagasawa, T; Utagawa, T; Goto, J; Kim, C J; Tani, Y; Kumagai, H; Yamada, H

    1981-06-01

    Degradation of tyrosine to phenol, pyruvate and ammonia by tyrosine phenol-lyase from Citrobacter intermedius (formerly named Escherichia intermedia) is readily reversible at high concentrations of pyruvate and ammonia. Spectrophotometric studies indicate that ammonia is the first substrate which interacts with bound pyridoxal 5'-phosphate. Kinetic results show that pyruvate is the second substrate bound, hence phenol must be the third. When an appropriate phenol derivative is substituted for phenol, the corresponding tyrosine analogue can be synthesized. 3-Fluoro-, 2-fluoro-, 3-chloro-, 2-chloro-, 3-bromo-, 2-bromo-, 2-iodo-, 3-methyl-, 2-methyl- and 2-methoxy-L-tyrosines have been synthesized by this reaction. By using various phenol derivatives or tyrosine analogues as substrates, the substrate specificity of tyrosine phenol-lyase is investigated and the situation of its active site is discussed.

  14. Inhibition of Candida albicans isocitrate lyase activity by sesterterpene sulfates from the tropical sponge Dysidea sp.

    Science.gov (United States)

    Lee, Dongha; Shin, Jongheon; Yoon, Kyung-Mi; Kim, Tae-Im; Lee, So-Hyoung; Lee, Hyi-Seung; Oh, Ki-Bong

    2008-10-15

    Seven sesterterpene sulfates (1-7) were isolated from the tropical sponge Dysidea sp. and their inhibitory activities against isocitrate lyase (ICL) from Candida albicans were evaluated. Among the isolated natural products compound 6 and 7 were found to be strong ICL inhibitors. The isolated compounds (1-7) also showed potent antibacterial effect against Bacillus subtilis and Proteus vulgaris, but did not display antifungal activity.

  15. Mechanism of benzaldehyde lyase studied via thiamin diphosphate-bound intermediates and kinetic isotope effects.

    Science.gov (United States)

    Chakraborty, Sumit; Nemeria, Natalia; Yep, Alejandra; McLeish, Michael J; Kenyon, George L; Jordan, Frank

    2008-03-25

    Direct spectroscopic observation of thiamin diphosphate-bound intermediates was achieved on the enzyme benzaldehyde lyase, which carries out reversible and highly enantiospecific conversion of ( R)-benzoin to benzaldehyde. The key enamine intermediate could be observed at lambda max 393 nm in the benzoin breakdown direction and in the decarboxylase reaction starting with benzoylformate. With benzaldehyde as substrate, no intermediates could be detected, only formation of benzoin at 314 nm. To probe the rate-limiting step in the direction of ( R)-benzoin synthesis, the (1)H/ (2)H kinetic isotope effect was determined for benzaldehyde labeled at the aldehyde position and found to be small (1.14 +/- 0.03), indicating that ionization of the C2alphaH from C2alpha-hydroxybenzylthiamin diphosphate is not rate limiting. Use of the alternate substrates benzoylformic and phenylpyruvic acids (motivated by the observation that while a carboligase, benzaldehyde lyase could also catalyze the slow decarboxylation of 2-oxo acids) enabled the observation of the substrate-thiamin covalent intermediate via the 1',4'-iminopyrimidine tautomer, characteristic of all intermediates with a tetrahedral C2 substituent on ThDP. The reaction of benzaldehyde lyase with the chromophoric substrate analogue ( E)-2-oxo-4(pyridin-3-yl)-3-butenoic acid and its decarboxylated product ( E)-3-(pyridine-3-yl)acrylaldehyde enabled the detection of covalent adducts with both. Neither adduct underwent further reaction. An important finding of the studies is that all thiamin-related intermediates are in a chiral environment on benzaldehyde lyase as reflected by their circular dichroism signatures.

  16. Accessibility and Use of Web-Based Electronic Resources by Physicians in a Psychiatric Institution in Nigeria

    Science.gov (United States)

    Oduwole, Adebambo Adewale; Oyewumi, Olatundun

    2010-01-01

    Purpose: This study aims to examine the accessibility and use of web-based electronic databases on the Health InterNetwork Access to Research Initiative (HINARI) portal by physicians in the Neuropsychiatric Hospital, Aro--a psychiatry health institution in Nigeria. Design/methodology/approach: Collection of data was through the use of a three-part…

  17. Genetically engineered alginate lyase-PEG conjugates exhibit enhanced catalytic function and reduced immunoreactivity.

    Directory of Open Access Journals (Sweden)

    John W Lamppa

    Full Text Available Alginate lyase enzymes represent prospective biotherapeutic agents for treating bacterial infections, particularly in the cystic fibrosis airway. To effectively deimmunize one therapeutic candidate while maintaining high level catalytic proficiency, a combined genetic engineering-PEGylation strategy was implemented. Rationally designed, site-specific PEGylation variants were constructed by orthogonal maleimide-thiol coupling chemistry. In contrast to random PEGylation of the enzyme by NHS-ester mediated chemistry, controlled mono-PEGylation of A1-III alginate lyase produced a conjugate that maintained wild type levels of activity towards a model substrate. Significantly, the PEGylated variant exhibited enhanced solution phase kinetics with bacterial alginate, the ultimate therapeutic target. The immunoreactivity of the PEGylated enzyme was compared to a wild type control using in vitro binding studies with both enzyme-specific antibodies, from immunized New Zealand white rabbits, and a single chain antibody library, derived from a human volunteer. In both cases, the PEGylated enzyme was found to be substantially less immunoreactive. Underscoring the enzyme's potential for practical utility, >90% of adherent, mucoid, Pseudomonas aeruginosa biofilms were removed from abiotic surfaces following a one hour treatment with the PEGylated variant, whereas the wild type enzyme removed only 75% of biofilms in parallel studies. In aggregate, these results demonstrate that site-specific mono-PEGylation of genetically engineered A1-III alginate lyase yielded an enzyme with enhanced performance relative to therapeutically relevant metrics.

  18. Phosphoserine Lyase Deoxyribozymes: DNA-Catalyzed Formation of Dehydroalanine Residues in Peptides.

    Science.gov (United States)

    Chandrasekar, Jagadeeswaran; Wylder, Adam C; Silverman, Scott K

    2015-08-05

    Dehydroalanine (Dha) is a nonproteinogenic electrophilic amino acid that is a synthetic intermediate or product in the biosynthesis of several bioactive cyclic peptides such as lantibiotics, thiopeptides, and microcystins. Dha also enables labeling of proteins and synthesis of post-translationally modified proteins and their analogues. However, current chemical approaches to introducing Dha into peptides have substantial limitations. Using in vitro selection, here we show that DNA can catalyze Zn(2+) or Zn(2+)/Mn(2+)-dependent formation of Dha from phosphoserine (pSer), i.e., exhibit pSer lyase activity, a fundamentally new DNA-catalyzed reaction. Two new pSer lyase deoxyribozymes, named Dha-forming deoxyribozymes 1 and 2 (DhaDz1 and DhaDz2), each function with multiple turnover on the model hexapeptide substrate that was used during selection. Using DhaDz1, we generated Dha from pSer within an unrelated linear 13-mer peptide. Subsequent base-promoted intramolecular cyclization of homocysteine into Dha formed a stable cystathionine (thioether) analogue of the complement inhibitor compstatin. These findings establish the fundamental catalytic ability of DNA to eliminate phosphate from pSer to form Dha and suggest that with further development, pSer lyase deoxyribozymes will have broad practical utility for site-specific enzymatic synthesis of Dha from pSer in peptide substrates.

  19. Production of Diamino propionic acid ammonia lyase by a new strain of Salmonella typhimurium PU011

    Directory of Open Access Journals (Sweden)

    Shiva Kumar Vasanth V

    2002-03-01

    Full Text Available Abstract Background Seeds of the legume plant Lathyrus sativus, which is grown in arid and semi arid tropical regions, contain Diamino Propionic acid (DAP. DAP is a neurotoxin, which, when consumed, causes a disease called Lathyrism. Lathryrism may manifest as Neurolathyrism or Osteolathyrism, in which the nervous system, and bone formation respectively, are affected. DAP ammonia lyase is produced by a few microorganisms such as Salmonella typhi, Salmonella typhimurium and Pseudomonas, and is capable of detoxifying DAP. Results S. typhimurium PU011, a non-virulent bacterial strain isolated in our lab, was found to produce DAP ammonia lyase enzyme when grown in minimal medium containing DAP. There was a direct correlation between biomass yield and enzyme activity, until 16 h post inoculation in minimal medium containing DAP. Following ammonium sulphate precipitation and passing through Sephadex G100, CM-Sephadex and DEAE-Sephacel for crude enzyme extract preparation, about 68-fold enzyme purity was obtained. The purified enzyme gave maximum activity at pH 8.0 and was stable up to 45 degrees C. The Km value for the substrate was found to be 0.685mM, calculated from a Line Weaver Burk plot. Conclusion A new bacterial strain, S.typhimurium PU 011, which is capable of producing DAP ammonia lyase, was isolated.

  20. Characterization of phycoviolobilin phycoerythrocyanin-alpha 84-cystein-lyase-(isomerizing) from Mastigocladus laminosus.

    Science.gov (United States)

    Zhao, Kai-Hong; Wu, Dong; Wang, Lu; Zhou, Ming; Storf, Max; Bubenzer, Claudia; Strohmann, Brigitte; Scheer, Hugo

    2002-09-01

    Cofactor requirements and enzyme kinetics have been studied of the novel, dual-action enzyme, the isomerizing phycoviolobilin phycoerythrocyanin-alpha84-cystein-lyase(PVB-PEC-lyase) from Mastigocladus laminosus, which catalyses both the covalent attachment of phycocyanobilin to PecA, the apo-alpha-subunit of phycoerythrocyanin, and its isomerization to phycoviolobilin. Thiols and the divalent metals, Mg2+ or Mn2+, were required, and the reaction was aided by the detergent, Triton X-100. Phosphate buffer inhibits precipitation of the proteins present in the reconstitution mixture, but at the same time binds the required metal. Kinetic constants were obtained for both substrates, the chromophore (Km = 12-16 micro m, depending on [PecA], kcat approximately 1.2 x 10-4.s-1) and the apoprotein (Km = 2.4 micro m at 14 micro m PCB, kcat = 0.8 x 10-4.s-1). The kinetic analysis indicated that the reconstitution reaction proceeds by a sequential mechanism. By a combination of untagged and His-tagged subunits, evidence was obtained for a complex formation between PecE and PecF (subunits of PVB-PEC-lyase), and by experiments with single subunits for the prevalent function of PecE in binding and PecF in isomerizing the chromophore.

  1. Effect of cysteine on the inactivation of cystathionine gamma-lyase by D,L-propargylglycine.

    Directory of Open Access Journals (Sweden)

    Awata,Shiro

    1989-12-01

    Full Text Available In vivo inactivation of cystathionine gamma-lyase by D,L-propargylglycine, a suicide inhibitor, was found to be less profound in rat kidney than in the liver. We investigated the cause of this difference using rat tissues. We fractionated kidney extract to characterize the substance which protected enzyme, and found that cysteine exhibits protecting action. Addition of 0.3 mM L-cysteine to the incubation mixture containing dialyzed kidney supernatant and 0.5 mM D,L-propargylglycine resulted in the protection of cystathionine gamma-lyase from the inactivation by the inhibitor. The content of cysteine in the kidney was six-fold higher than that in the liver. Thus, we have concluded that one of the reasons why the in vivo inactivation of cystathionine gamma-lyase in rat kidney was less than that in the liver is the presence of a higher concentration of cysteine in the kidney. S-Carboxymethylcysteine, a cysteine derivative, exhibited a similar, but weaker, protective effect.

  2. Improvement of aromatic thiol release through the selection of yeasts with increased β-lyase activity.

    Science.gov (United States)

    Belda, Ignacio; Ruiz, Javier; Navascués, Eva; Marquina, Domingo; Santos, Antonio

    2016-05-16

    The development of a selective medium for the rapid differentiation of yeast species with increased aromatic thiol release activity has been achieved. The selective medium was based on the addition of S-methyl-l-cysteine (SMC) as β-lyase substrate. In this study, a panel of 245 strains of Saccharomyces cerevisiae strains was tested for their ability to grow on YCB-SMC medium. Yeast strains with an increased β-lyase activity grew rapidly because of their ability to release ammonium from SMC in comparison to others, and allowed for the easy isolation and differentiation of yeasts with promising properties in oenology, or another field, for aromatic thiol release. The selective medium was also helpful for the discrimination between those S. cerevisiae strains, which present a common 38-bp deletion in the IRC7 sequence (present in around 88% of the wild strains tested and are likely to be less functional for 4-mercapto-4-methylpentan-2-one (4MMP) production), and those S. cerevisiae strains homozygous for the full-length IRC7 allele. The medium was also helpful for the selection of non-Saccharomyces yeasts with increased β-lyase activity. Based on the same medium, a highly sensitive, reproducible and non-expensive GC-MS method for the evaluation of the potential volatile thiol release by different yeast isolates was developed.

  3. Rev1 is a base excision repair enzyme with 5′-deoxyribose phosphate lyase activity

    Science.gov (United States)

    Prasad, Rajendra; Poltoratsky, Vladimir; Hou, Esther W.; Wilson, Samuel H.

    2016-01-01

    Rev1 is a member of the Y-family of DNA polymerases and is known for its deoxycytidyl transferase activity that incorporates dCMP into DNA and its ability to function as a scaffold factor for other Y-family polymerases in translesion bypass events. Rev1 also is involved in mutagenic processes during somatic hypermutation of immunoglobulin genes. In light of the mutation pattern consistent with dCMP insertion observed earlier in mouse fibroblast cells treated with a base excision repair-inducing agent, we questioned whether Rev1 could also be involved in base excision repair (BER). Here, we uncovered a weak 5′-deoxyribose phosphate (5′-dRP) lyase activity in mouse Rev1 and demonstrated the enzyme can mediate BER in vitro. The full-length Rev1 protein and its catalytic core domain are similar in their ability to support BER in vitro. The dRP lyase activity in both of these proteins was confirmed by NaBH4 reduction of the Schiff base intermediate and kinetics studies. Limited proteolysis, mass spectrometry and deletion analysis localized the dRP lyase active site to the C-terminal segment of Rev1's catalytic core domain. These results suggest that Rev1 could serve as a backup polymerase in BER and could potentially contribute to AID-initiated antibody diversification through this activity. PMID:27683219

  4. Induction of L-phenylalanine ammonia-lyase during utilization of phenylalanine as a carbon or nitrogen source in Rhodotorula glutinis.

    OpenAIRE

    Marusich, W C; Jensen, R A; Zamir, L O

    1981-01-01

    Rhodotorula glutinis is a convenient source of L-phenylalanine ammonia-lyase, an enzyme that is useful as a biochemical reagent in the assay of L-phenylalanine. There have been previous descriptions of induced lyase production in complex medium where induction occurs late in exponential growth, suggesting a role in secondary metabolism such as is the case in higher plants. A higher specific activity of L-phenylalanine ammonia-lyase (sixfold higher than a complex medium) can be obtained during...

  5. Share and share alike: encouraging the reuse of academic resources through the Scottish electronic Staff Development Library

    Directory of Open Access Journals (Sweden)

    Lorna M. Campbell

    2001-12-01

    Full Text Available The Scottish electronic Staff Development Library (http://www.sesdl.scotcit.acuk is an ongoing collaborative project involving the Universities of Edinburgh, Paisley and Strathclyde which has been funded by SHEFC as part of their current ScotCIT Programme (http:llwww.scotcit.ac.uk. This project is being developed in response to the increasing demand for flexible, high-quality staff development materials.

  6. Molecular cloning, purification, and characterization of a novel polyMG-specific alginate lyase responsible for alginate MG block degradation in Stenotrophomas maltophilia KJ-2

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su In; Kim, Hee Sook [Kyungsung Univ., Busan (Korea, Republic of). Dept. of Food Science and Biotechnology; Choi, Sung Hee; Lee, Eun Yeol [Kyung Hee Univ., Gyeonggi-do (Korea, Republic of). Dept. of Chemical Engineering

    2012-09-15

    A gene for a polyMG-specific alginate lyase possessing a novel structure was identified and cloned from Stenotrophomas maltophilia KJ-2 by using PCR with homologous nucleotide sequences-based primers. The recombinant alginate lyase consisting of 475 amino acids was purified on Ni-Sepharose column and exhibited the highest activity at pH 8 and 40 C. Interestingly, the recombinant alginate lyase was expected to have a similar catalytic active site of chondroitin B lyase but did not show chondroitin lyase activity. In the test of substrate specificity, the recombinant alginate lyase preferentially degraded the glycosidic bond of polyMG-block than polyM-block and polyG-block. The chemical structures of the degraded alginate oligosaccharides were elucidated to have mannuronate (M) at the reducing end on the basis of NMR analysis, supporting that KJ-2 polyMG-specific alginate lyase preferably degraded the glycosidic bond in M-G linkage than that in G-M linkage. The KJ-2 polyMG-specific alginate lyase can be used in combination with other alginate lyases for a synergistic saccharification of alginate. (orig.)

  7. 重庆高校图书馆电子文献资源建设现状及对策%The Present Situation and Countermeasure of Electronic Literature Resources Construction about Chongqing University Library

    Institute of Scientific and Technical Information of China (English)

    刘子辉; 彭渝; 陈强; 吴晓英

    2014-01-01

    In the information society, Electronic document resources are very important for library development and the school's teaching and research. The university library should pay more at ention to the construction of electronic document resources. Through the survey of the electronic document resources in Chongqing, We have mastered the distribution of electronic document resources, analyzed the existing problems in resource construction, and proposed the related countermeasure. We hope to provide reference for the electronic document resources construction.%在信息社会,电子文献资源对高校图书馆建设、学校的教学与科研都起到非常重要的作用,各高校图书馆应该更加重视电子文献资源的建设。通过对重庆高校图书馆电子文献资源建设情况进行调查,掌握了本地区电子文献资源的分布情况,分析了资源建设中存在的问题,并提出了相关对策,希望为本地区高校图书馆电子文献资源建设提供参考。

  8. Selection and Evaluation of Electronic Resources Elektronik Kaynakların Seçimi ve Değerlendirilmesi

    Directory of Open Access Journals (Sweden)

    Doğan Atılgan

    2009-12-01

    Full Text Available Publication boom and issues related to controlling and accession of printed sources have created some problems after World War II. Consequently, publishing industry has encountered the problem of finding possible solution for emerged situation. Industry of electronic publishing has started to improve with the rapid increase of the price of printed sources as well as the problem of publication boom. The first effects of electronic publishing were appeared on the academic and scholarly publications then electronic publishing became a crucial part of all types of publications. As a result of these developments, collection developments and service policies of information centers were also significantly changed. In this article, after a general introduction about selection and evaluation processes of electronic publications, the subscribed databases by a state and a privately owned university in Turkey and their usage were examined. İkinci dünya savaşından sonra görülen yayın patlaması, basılı kaynakların denetim ve erişiminde sorunlar yaşanmasına neden olmuştur. Bu da yayıncılık sektöründe yeni arayışlara yol açmıştır. 1980’li yıllardan sonra basılı yayın fiyatlarındaki hızlı artış da bu etmenlere eklenince elektronik yayıncılık sektörü gelişmeye başlamıştır. Öncelikle bilimsel ve akademik yayınlarla başlayan elektronik yayın günümüzde tüm yayın türlerini kapsamaktadır. Yayıncılıktaki bu gelişim bilgi merkezlerinin derme geliştirme ve hizmet politikalarını da önemli ölçüde değiştirmiştir. Bu çalışmada elektronik yayınların seçim, değerlendirme ve sağlama konularında genel bir girişten sonra bir devlet üniversitesinin bir de özel üniversitenin abone olduğu veritabanları ve bu veri tabanlarının kullanımının değerlendirilmesi yapılmaktadır.

  9. Cysteine S-conjugate β-lyases: important roles in the metabolism of naturally occurring sulfur and selenium-containing compounds, xenobiotics and anticancer agents.

    Science.gov (United States)

    Cooper, Arthur J L; Krasnikov, Boris F; Niatsetskaya, Zoya V; Pinto, John T; Callery, Patrick S; Villar, Maria T; Artigues, Antonio; Bruschi, Sam A

    2011-06-01

    Cysteine S-conjugate β-lyases are pyridoxal 5'-phosphate-containing enzymes that catalyze β-elimination reactions with cysteine S-conjugates that possess a good leaving group in the β-position. The end products are aminoacrylate and a sulfur-containing fragment. The aminoacrylate tautomerizes and hydrolyzes to pyruvate and ammonia. The mammalian cysteine S-conjugate β-lyases thus far identified are enzymes involved in amino acid metabolism that catalyze β-lyase reactions as non-physiological side reactions. Most are aminotransferases. In some cases the lyase is inactivated by reaction products. The cysteine S-conjugate β-lyases are of much interest to toxicologists because they play an important key role in the bioactivation (toxication) of halogenated alkenes, some of which are produced on an industrial scale and are environmental contaminants. The cysteine S-conjugate β-lyases have been reviewed in this journal previously (Cooper and Pinto in Amino Acids 30:1-15, 2006). Here, we focus on more recent findings regarding: (1) the identification of enzymes associated with high-M(r) cysteine S-conjugate β-lyases in the cytosolic and mitochondrial fractions of rat liver and kidney; (2) the mechanism of syncatalytic inactivation of rat liver mitochondrial aspartate aminotransferase by the nephrotoxic β-lyase substrate S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (the cysteine S-conjugate of tetrafluoroethylene); (3) toxicant channeling of reactive fragments from the active site of mitochondrial aspartate aminotransferase to susceptible proteins in the mitochondria; (4) the involvement of cysteine S-conjugate β-lyases in the metabolism/bioactivation of drugs and natural products; and (5) the role of cysteine S-conjugate β-lyases in the metabolism of selenocysteine Se-conjugates. This review emphasizes the fact that the cysteine S-conjugate β-lyases are biologically more important than hitherto appreciated.

  10. Kinetic and thermodynamic properties of alginate lyase and cellulase co-produced by Exiguobacterium species Alg-S5.

    Science.gov (United States)

    Mohapatra, Bidyut R

    2017-05-01

    In an effort to screen out the alginolytic and cellulolytic bacteria from the putrefying invasive seaweed Sargassum species accumulated off Barbados' coast, a potent bacterial strain was isolated. This bacterium, which simultaneously produced alginate lyase and cellulase, was identified as Exiguobacterium sp. Alg-S5 via the phylogenetic approach targeting the 16S rRNA gene. The co-produced alginate lyase and cellulase exhibited maximal enzymatic activity at pH 7.5 and at 40°C and 45°C, respectively. The Km and Vmax values recorded as 0.91mg/mL and 21.8U/mg-protein, respectively, for alginate lyase, and 10.9mg/mL and 74.6U/mg-protein, respectively, for cellulase. First order kinetic analysis of the thermal denaturation of the co-produced alginate lyase and cellulase in the temperature range from 40°C to 55°C revealed that both the enzymes were thermodynamically efficient by displaying higher activation energy and enthalpy of denaturation. These enzymatic properties indicate the potential industrial importance of this bacterium in algal biomass conversion. This appears to be the first report on assessing the efficacy of a bacterium for the co-production of alginate lyase and cellulase.

  11. Ammonia lyases and aminomutases as biocatalysts for the synthesis of α-amino and β-amino acids.

    Science.gov (United States)

    Turner, Nicholas J

    2011-04-01

    Ammonia lyases catalyse the reversible addition of ammonia to cinnamic acid (1: R=H) and p-hydroxycinnamic (1: R=OH) to generate L-phenylalanine (2: R=H) and L-tyrosine (2: R=OH) respectively (Figure 1a). Both phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) are widely distributed in plants, fungi and prokaryotes. Recently there has been interest in the use of these enzymes for the synthesis of a broader range of L-arylalanines. Aminomutases catalyse a related reaction, namely the interconversion of α-amino acids to β-amino acids (Figure 1b). In the case of L-phenylalanine, this reaction is catalysed by phenylalanine aminomutase (PAM) and proceeds stereospecifically via the intermediate cinnamic acid to generate β-Phe 3. Ammonia lyases and aminomutases are related in sequence and structure and share the same active site cofactor 4-methylideneimidazole-5-one (MIO). There is currently interest in the possibility of using these biocatalysts to prepare a wide range of enantiomerically pure l-configured α-amino and β-amino acids. Recent reviews have focused on the mechanism of these MIO containing enzymes. The aim of this review is to review recent progress in the application of ammonia lyase and aminomutase enzymes to prepare enantiomerically pure α-amino and β-amino acids.

  12. Methanopyrus kandleri topoisomerase V contains three distinct AP lyase active sites in addition to the topoisomerase active site.

    Science.gov (United States)

    Rajan, Rakhi; Osterman, Amy; Mondragón, Alfonso

    2016-04-20

    Topoisomerase V (Topo-V) is the only topoisomerase with both topoisomerase and DNA repair activities. The topoisomerase activity is conferred by a small alpha-helical domain, whereas the AP lyase activity is found in a region formed by 12 tandem helix-hairpin-helix ((HhH)2) domains. Although it was known that Topo-V has multiple repair sites, only one had been mapped. Here, we show that Topo-V has three AP lyase sites. The atomic structure and Small Angle X-ray Scattering studies of a 97 kDa fragment spanning the topoisomerase and 10 (HhH)2 domains reveal that the (HhH)2 domains extend away from the topoisomerase domain. A combination of biochemical and structural observations allow the mapping of the second repair site to the junction of the 9th and 10th (HhH)2 domains. The second site is structurally similar to the first one and to the sites found in other AP lyases. The 3rd AP lyase site is located in the 12th (HhH)2 domain. The results show that Topo-V is an unusual protein: it is the only known protein with more than one (HhH)2 domain, the only known topoisomerase with dual activities and is also unique by having three AP lyase repair sites in the same polypeptide.

  13. Utility of the electronic information resource UpToDate for clinical decision-making at bedside rounds.

    Science.gov (United States)

    Phua, J; See, K C; Khalizah, H J; Low, S P; Lim, T K

    2012-02-01

    Clinical questions often arise at daily hospital bedside rounds. Yet, little information exists on how the search for answers may be facilitated. The aim of this prospective study was, therefore, to evaluate the overall utility, including the feasibility and usefulness of incorporating searches of UpToDate, a popular online information resource, into rounds. Doctors searched UpToDate for any unresolved clinical questions during rounds for patients in general medicine and respiratory wards, and in the medical intensive care unit of a tertiary teaching hospital. The nature of the questions and the results of the searches were recorded. Searches were deemed feasible if they were completed during the rounds and useful if they provided a satisfactory answer. A total of 157 UpToDate searches were performed during the study period. Questions were raised by all ranks of clinicians from junior doctors to consultants. The searches were feasible and performed immediately during rounds 44% of the time. Each search took a median of three minutes (first quartile: two minutes, third quartile: five minutes). UpToDate provided a useful and satisfactory answer 75% of the time, a partial answer 17% of the time and no answer 9% of the time. It led to a change in investigations, diagnosis or management 37% of the time, confirmed what was originally known or planned 38% of the time and had no effect 25% of the time. Incorporating UpToDate searches into daily bedside rounds was feasible and useful in clinical decision-making.

  14. Metabolism of β-valine via a CoA-dependent ammonia lyase pathway.

    Science.gov (United States)

    Otzen, Marleen; Crismaru, Ciprian G; Postema, Christiaan P; Wijma, Hein J; Heberling, Matthew M; Szymanski, Wiktor; de Wildeman, Stefaan; Janssen, Dick B

    2015-11-01

    Pseudomonas species strain SBV1 can rapidly grow on medium containing β-valine as a sole nitrogen source. The tertiary amine feature of β-valine prevents direct deamination reactions catalyzed by aminotransferases, amino acid dehydrogenases, and amino acid oxidases. However, lyase- or aminomutase-mediated conversions would be possible. To identify enzymes involved in the degradation of β-valine, a PsSBV1 gene library was prepared and used to complement the β-valine growth deficiency of a closely related Pseudomonas strain. This resulted in the identification of a gene encoding β-valinyl-coenzyme A ligase (BvaA) and two genes encoding β-valinyl-CoA ammonia lyases (BvaB1 and BvaB2). The BvaA protein demonstrated high sequence identity to several known phenylacetate CoA ligases. Purified BvaA enzyme did not convert phenyl acetic acid but was able to activate β-valine in an adenosine triphosphate (ATP)- and CoA-dependent manner. The substrate range of the enzyme appears to be narrow, converting only β-valine and to a lesser extent, 3-aminobutyrate and β-alanine. Characterization of BvaB1 and BvaB2 revealed that both enzymes were able to deaminate β-valinyl-CoA to produce 3-methylcrotonyl-CoA, a common intermediate in the leucine degradation pathway. Interestingly, BvaB1 and BvaB2 demonstrated no significant sequence identity to known CoA-dependent ammonia lyases, suggesting they belong to a new family of enzymes. BLAST searches revealed that BvaB1 and BvaB2 show high sequence identity to each other and to several enoyl-CoA hydratases, a class of enzymes that catalyze a similar reaction with water instead of amine as the leaving group.

  15. Structural insights into catalysis by βC-S lyase from Streptococcus anginosus.

    Science.gov (United States)

    Kezuka, Yuichiro; Yoshida, Yasuo; Nonaka, Takamasa

    2012-10-01

    Hydrogen sulfide (H(2)S) is a causative agent of oral malodor and may play an important role in the pathogenicity of oral bacteria such as Streptococcus anginosus. In this microorganism, H(2)S production is associated with βC-S lyase (Lcd) encoded by lcd gene, which is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the α,β-elimination of sulfur-containing amino acids. When Lcd acts on L-cysteine, H(2)S is produced along with pyruvate and ammonia. To understand the H(2)S-producing mechanism of Lcd in detail, we determined the crystal structures of substrate-free Lcd (internal aldimine form) and two reaction intermediate complexes (external aldimine and α-aminoacrylate forms). The formation of intermediates induced little changes in the overall structure of the enzyme and in the active site residues, with the exception of Lys234, a PLP-binding residue. Structural and mutational analyses highlighted the importance of the active site residues Tyr60, Tyr119, and Arg365. In particular, Tyr119 forms a hydrogen bond with the side chain oxygen atom of L-serine, a substrate analog, in the external aldimine form suggesting its role in the recognition of the sulfur atom of the true substrate (L-cysteine). Tyr119 also plays a role in fixing the PLP cofactor at the proper position during catalysis through binding with its side chain. Finally, we partly modified the catalytic mechanism known for cystalysin, a βC-S lyase from Treponema denticola, and proposed an improved mechanism, which seems to be common to the βC-S lyases from oral bacteria.

  16. Composite active site of chondroitin lyase ABC accepting both epimers of uronic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shaya, D.; Hahn, Bum-Soo; Bjerkan, Tonje Marita; Kim, Wan Seok; Park, Nam Young; Sim, Joon-Soo; Kim, Yeong-Shik; Cygler, M. (Catholic Univ of Korea); (NUST); (McGill); (Nat); (Natural Products Res Inst, Korea)

    2008-03-19

    Enzymes have evolved as catalysts with high degrees of stereospecificity. When both enantiomers are biologically important, enzymes with two different folds usually catalyze reactions with the individual enantiomers. In rare cases a single enzyme can process both enantiomers efficiently, but no molecular basis for such catalysis has been established. The family of bacterial chondroitin lyases ABC comprises such enzymes. They can degrade both chondroitin sulfate (CS) and dermatan sulfate (DS) glycosaminoglycans at the nonreducing end of either glucuronic acid (CS) or its epimer iduronic acid (DS) by a {beta}-elimination mechanism, which commences with the removal of the C-5 proton from the uronic acid. Two other structural folds evolved to perform these reactions in an epimer-specific fashion: ({alpha}/{alpha}){sub 5} for CS (chondroitin lyases AC) and {beta}-helix for DS (chondroitin lyases B); their catalytic mechanisms have been established at the molecular level. The structure of chondroitinase ABC from Proteus vulgaris showed surprising similarity to chondroitinase AC, including the presence of a Tyr-His-Glu-Arg catalytic tetrad, which provided a possible mechanism for CS degradation but not for DS degradation. We determined the structure of a distantly related Bacteroides thetaiotaomicron chondroitinase ABC to identify additional structurally conserved residues potentially involved in catalysis. We found a conserved cluster located {approx}12 {angstrom} from the catalytic tetrad. We demonstrate that a histidine in this cluster is essential for catalysis of DS but not CS. The enzyme utilizes a single substrate-binding site while having two partially overlapping active sites catalyzing the respective reactions. The spatial separation of the two sets of residues suggests a substrate-induced conformational change that brings all catalytically essential residues close together.

  17. Strict reaction and substrate specificity of AGXT2L1, the human O-phosphoethanolamine phospho-lyase.

    Science.gov (United States)

    Schiroli, Davide; Cirrincione, Simona; Donini, Stefano; Peracchi, Alessio

    2013-07-01

    Dysregulated expression of the AGXT2L1 gene has been associated to neuropsychiatric disorders. Recently the gene product was shown to possess O-phosphoethanolamine phospho-lyase activity. We here analyze the specificity of AGXT2L1 in terms of both reaction and substrate. We show that the enzyme, despite having evolved from a transaminase ancestor, is at least 500-fold more active as a lyase than as an aminotransferase. Furthermore, the lyase reaction is very selective for O-phosphoethanolamine, strongly discriminating against closely related compounds, and we dissect the factors that contribute to such narrow substrate specificity. Overall, AGXT2L1 function appears to be rigidly confined to phospholipid metabolism, which is altered in neuropsychiatric disturbances. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  18. Molecular cloning and characterization of l-methionine γ-lyase from Streptomyces avermitilis.

    Science.gov (United States)

    Kudou, Daizou; Yasuda, Eri; Hirai, Yoshiyuki; Tamura, Takashi; Inagaki, Kenji

    2015-10-01

    A pyridoxal 5'-phosphate-dependent methionine γ-lyase (MGL) was cloned from Streptomyces avermitilis catalyzed the degradation of methionine to α-ketobutyrate, methanethiol, and ammonia. The sav7062 gene (1,242 bp) was corresponded to 413 amino acid residues with a molecular mass of 42,994 Da. The deduced amino acid sequence showed a high degree of similarity to those of other MGL enzymes. The sav7062 gene was overexpressed in Escherichia coli. The enzyme was purified to homogeneity and exhibited the MGL catalytic activities. We cloned the enzyme that has the MGL activity in Streptomyces for the first time.

  19. Structural Insights into Substrate Specificity and the anti beta-Elimination Mechanism of Pectate Lyase

    DEFF Research Database (Denmark)

    Seyedarabi, A.; To, T.T.; Ali, S.

    2010-01-01

    Pectate lyases harness anti beta-elimination chemistry to cleave the alpha-1,4 linkage in the homogalacturonan region of plant cell Wall pectin. We have studied the binding of five pectic oligosaccharides to Bacillus subtilis pectate Iyase in crystals of the inactive enzyme in which the catalytic...... base is substituted with alanine (R279A). We discover that the three central subsites (- 1, + 1, and +2) have a profound preference for galacturonate but that the distal subsites call accommodate methylated galactUronate. h Is reasonable to assume therefore that pectate Iyase call cleave pectin...

  20. Effect of cysteine on the inactivation of cystathionine gamma-lyase by D,L-propargylglycine.

    OpenAIRE

    Awata,Shiro; Nakayama,Kazuko; SUZUKI, Isao; Kodama, Hiroyuki

    1989-01-01

    In vivo inactivation of cystathionine gamma-lyase by D,L-propargylglycine, a suicide inhibitor, was found to be less profound in rat kidney than in the liver. We investigated the cause of this difference using rat tissues. We fractionated kidney extract to characterize the substance which protected enzyme, and found that cysteine exhibits protecting action. Addition of 0.3 mM L-cysteine to the incubation mixture containing dialyzed kidney supernatant and 0.5 mM D,L-propargylglycine resulted i...

  1. Crystallization and preliminary X-ray analysis of pectin lyase A from Aspergillus niger.

    Science.gov (United States)

    Jenkins, J; Scott, M; Mayans, O; Pickersgill, R; Harris, G; Connerton, I; Gravesen, T

    1996-03-01

    The major secreted pectin lyase (E.C. 4.2.2.10) from Aspergillus niger, strain 4M-147, has been purified and crystallized by the hanging-drop method using polyethylene glycol as precipitant. The crystals belong to the space group P2(1)2(1)2(1) with cell dimensions a = 45.2, b = 83.2, c = 93.1 A (1 A = 0.1 nm) and a single molecule in the asymmetric unit. The crystals diffract to at least 2.0 A resolution and are suitable for structure determination.

  2. Potato signal molecules that activate pectate lyase synthesis in Pectobacterium atrosepticum SCRI1043.

    Science.gov (United States)

    Tarasova, Nadezhda; Gorshkov, Vladimir; Petrova, Olga; Gogolev, Yuri

    2013-07-01

    A new type of plant-derived signal molecules that activate extracellular pectate lyase activity in phytopathogenic bacterium Pectobacterium atrosepticum SCRI1043 was revealed. These compounds were characterized and partially purified by means of several approaches including RT-PCR analysis, luminescence bioassay and HPLC fractionation. They were smaller than 1 kDa, thermoresistant, nonproteinaceous, hydrophilic, and slightly negatively charged molecules. Using gene expression analysis and bacterial biosensor assay the mode of activity of revealed compounds was studied. The possibility of their action through quorum sensing- and KdgR-mediated pathways was analyzed.

  3. Bacterial Anabaena variabilis phenylalanine ammonia lyase: a biocatalyst with broad substrate specificity.

    Science.gov (United States)

    Lovelock, Sarah L; Turner, Nicholas J

    2014-10-15

    Phenylalanine ammonia lyases (PALs) catalyse the regio- and stereoselective hydroamination of cinnamic acid analogues to yield optically enriched α-amino acids. Herein, we demonstrate that a bacterial PAL from Anabaena variabilis (AvPAL) displays significantly higher activity towards a series of non-natural substrates than previously described eukaryotic PALs. Biotransformations performed on a preparative scale led to the synthesis of the 2-chloro- and 4-trifluoromethyl-phenylalanine derivatives in excellent ee, highlighting the enormous potential of bacterial PALs as biocatalysts for the synthesis of high value, non-natural amino acids.

  4. Enhancing Production of Alkaline Polygalacturonate Lyase from Bacillus subtilis by Fed-Batch Fermentation

    OpenAIRE

    Mouyong Zou; Fenfen Guo; Xuezhi Li; Jian Zhao; Yinbo Qu

    2014-01-01

    Alkaline polygalacturonate lyase (PGL, EC 4.2.2.2) is an enzyme used in many industries. We developed a fed-batch fermentation process that combines the enzymatic pretreatment of the carbon source with controlling the pH of the fermentative broth to enhance the PGL production from Bacillus subtilis 7-3-3 to decrease the production cost. Maintaining the fermentation broth at pH 6.5 prior to feeding with ammonia and at pH 6.0 after feeding significantly improved PGL activity (743.5 U mL-1) comp...

  5. One-step purification and characterization of alginate lyase from a clinical Pseudomonas aeruginosa with destructive activity on bacterial biofilm

    Directory of Open Access Journals (Sweden)

    Parinaz Ghadam

    2017-05-01

    Full Text Available Objective(s: Pseudomonas aeruginosais a Gram-negative and aerobic rod bacterium that displays mucoid and non-mucoid phenotype. Mucoid strains secrete alginate, which is the main agent of biofilms in chronic P. aeruginosa infections, show high resistance to antibiotics; consequently, the biological disruption of mucoid P. aeruginosa biofilms is an attractive area of study for researchers. Alginate lyase gene (algl is a member of alginate producing operon which by glycosidase activity produces primer for other enzymes in this cluster. Also this activity can destroy the extracellular alginate; therefore this enzyme participates in alginate production and destruction pathway. Alginate lyase causes detachment of a biofilm by reducing its adhesion to the surfaces, and increases phagocytosis and antibiotic susceptibility. In this study, alginate lyase was purified in just one step and its properties were investigated. Materials and Methods: The purification was done by affinity chromatography, analysed by SDS-PAGE, and its effect on P. aeruginosa biofilms was surveyed by micro titer plate assay and SEM. The substrate specificity of the enzyme was determined by PCR. Results: Alginate lyase from isolate 48 was purified in one step. It is more thermally resistant than alginate lyase from Pseudomonas aeruginosa PAO1 and poly M, poly G and poly MG alginate were the substrate of this enzyme. Moreover, it has an eradication effect on biofilms from P. aeruginosa 48 and PAO1. Conclusion: In this study an alginate lyase with many characteristics suitable in medicine such as thermal stability, effective on poly M alginate, and bacterial biofilm destructive was introduced and purified.

  6. Entropic origin of cobalt-carbon bond cleavage catalysis in adenosylcobalamin-dependent ethanolamine ammonia-lyase.

    Science.gov (United States)

    Wang, Miao; Warncke, Kurt

    2013-10-09

    Adenosylcobalamin-dependent enzymes accelerate the cleavage of the cobalt-carbon (Co-C) bond of the bound coenzyme by >10(10)-fold. The cleavage-generated 5'-deoxyadenosyl radical initiates the catalytic cycle by abstracting a hydrogen atom from substrate. Kinetic coupling of the Co-C bond cleavage and hydrogen-atom-transfer steps at ambient temperatures has interfered with past experimental attempts to directly address the factors that govern Co-C bond cleavage catalysis. Here, we use time-resolved, full-spectrum electron paramagnetic resonance spectroscopy, with temperature-step reaction initiation, starting from the enzyme-coenzyme-substrate ternary complex and (2)H-labeled substrate, to study radical pair generation in ethanolamine ammonia-lyase from Salmonella typhimurium at 234-248 K in a dimethylsulfoxide/water cryosolvent system. The monoexponential kinetics of formation of the (2)H- and (1)H-substituted substrate radicals are the same, indicating that Co-C bond cleavage rate-limits radical pair formation. Analysis of the kinetics by using a linear, three-state model allows extraction of the microscopic rate constant for Co-C bond cleavage. Eyring analysis reveals that the activation enthalpy for Co-C bond cleavage is 32 ± 1 kcal/mol, which is the same as for the cleavage reaction in solution. The origin of Co-C bond cleavage catalysis in the enzyme is, therefore, the large, favorable activation entropy of 61 ± 6 cal/(mol·K) (relative to 7 ± 1 cal/(mol·K) in solution). This represents a paradigm shift from traditional, enthalpy-based mechanisms that have been proposed for Co-C bond-breaking in B12 enzymes. The catalysis is proposed to arise from an increase in protein configurational entropy along the reaction coordinate.

  7. A Case of Dilated Cardiomyopathy Associated with 3-Hydroxy-3-Methylglutaryl-Coenzyme A (HMG CoA Lyase Deficiency

    Directory of Open Access Journals (Sweden)

    Alexander A. C. Leung

    2009-01-01

    Full Text Available 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA lyase deficiency is an inborn error of metabolism characterized by impairment of ketogenesis and leucine catabolism resulting in an organic acidopathy. In 1994, a case of dilated cardiomyopathy and fatal arrhythmia was reported in a 7-month-old infant. We report a case of dilated cardiomyopathy in association with HMG CoA lyase deficiency in a 23-year-old man with the acute presentation of heart failure. To our knowledge, this is the first case reported in an adult.

  8. 图书馆纸质资源与电子资源投入比例研究%The research of ratio between traditional and electronics resources in library

    Institute of Scientific and Technical Information of China (English)

    王以婧; 李明

    2012-01-01

    With the popularization of electronic product development,library is no longer the paper-based resources into a single information carrier the pattern,but has formed a paper resource and electronic resources coexist in the new situation.Because the library types of our country,the proportion of input between paper-based resources and other kinds of resources exist difference.This paper will discuss the relationship between the traditional and electronics resources,and also points out the existing problems and the countermeasures.%随着电子产品的普及发展,图书馆已不再以纸质资源为唯一的信息载体,而是形成了纸质资源和电子资源并存的新局面。由于国内图书馆类型的不同,纸质资源与电子资源的配比也会存在差异。通过讨论二者的关系,指出存在的问题及应对之策。

  9. A novel thermostable, alkaline pectate lyase from Bacillus tequilensis SV11 with potential in textile industry.

    Science.gov (United States)

    Chiliveri, Swarupa Rani; Linga, Venkateswar Rao

    2014-10-13

    An extracellular pectate lyase was purified and characterized from a UV mutant of Bacillus tequilensis SV11. Purification resulted in a 16.2-fold improvement in the enzyme specific activity, with approximately 40.2% yield. SDS-PAGE showed that the enzyme had two subunits with molecular masses of 135 ± 2 and 43 ± 2 kDa. Further, MALDI-TOF MS experiments revealed that the mass spectrum of the second peptide significantly (91% score) matched with the unsaturated rhamnogalacturonyl hydrolase YteR OS-Bacillus subtilis (strain 168) by 27% sequence coverage, nominal mass 43,231 Da, and PI 5.91. The enzyme was optimally active at 60 °C, pH 9. Km and Vmax of the purified pectate lyase was found to be 1.220 mg/mL and 1773 U/mL, respectively. The enzyme was studied for its applicability in bioscouring and found to be efficient in the removal of 97.91% pectin of cotton fabric when compared with alkali-treated fabric.

  10. Expression, purification and crystallization of l-methionine γ-lyase 2 from Entamoeba histolytica

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Dan [Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Yamagata, Wataru; Kamei, Kaeko [Graduate School of Science and Technology, Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Nozaki, Tomoyoshi [Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Harada, Shigeharu, E-mail: harada@kit.ac.jp [Graduate School of Science and Technology, Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan)

    2006-10-01

    l-Methionine γ-lyase 2 from E. histolytica, a key enzyme in sulfur-containing amino-acid degradation in this protozoan parasite, has been crystallized in a form suitable for X-ray structure analysis. l-Methionine γ-lyase (MGL) is considered to be an attractive target for rational drug development because the enzyme is absent in mammalian hosts. To enable structure-based design of drugs targeting MGL, one of the two MGL isoenzymes (EhMGL2) was crystallized in the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 88.89, b = 102.68, c = 169.87 Å. The crystal diffracted to a resolution of 2.0 Å. The presence of a tetramer in the asymmetric unit (4 × 43.1 kDa) gives a Matthews coefficient of 2.2 Å{sup 3} Da{sup −1}. The structure was solved by the molecular-replacement method and structure refinement is now in progress.

  11. Utilization of Glyphosate as Phosphate Source: Biochemistry and Genetics of Bacterial Carbon-Phosphorus Lyase

    Science.gov (United States)

    Zechel, David L.; Jochimsen, Bjarne

    2014-01-01

    SUMMARY After several decades of use of glyphosate, the active ingredient in weed killers such as Roundup, in fields, forests, and gardens, the biochemical pathway of transformation of glyphosate phosphorus to a useful phosphorus source for microorganisms has been disclosed. Glyphosate is a member of a large group of chemicals, phosphonic acids or phosphonates, which are characterized by a carbon-phosphorus bond. This is in contrast to the general phosphorus compounds utilized and metabolized by microorganisms. Here phosphorus is found as phosphoric acid or phosphate ion, phosphoric acid esters, or phosphoric acid anhydrides. The latter compounds contain phosphorus that is bound only to oxygen. Hydrolytic, oxidative, and radical-based mechanisms for carbon-phosphorus bond cleavage have been described. This review deals with the radical-based mechanism employed by the carbon-phosphorus lyase of the carbon-phosphorus lyase pathway, which involves reactions for activation of phosphonate, carbon-phosphorus bond cleavage, and further chemical transformation before a useful phosphate ion is generated in a series of seven or eight enzyme-catalyzed reactions. The phn genes, encoding the enzymes for this pathway, are widespread among bacterial species. The processes are described with emphasis on glyphosate as a substrate. Additionally, the catabolism of glyphosate is intimately connected with that of aminomethylphosphonate, which is also treated in this review. Results of physiological and genetic analyses are combined with those of bioinformatics analyses. PMID:24600043

  12. Genome-wide characterization of the Pectate Lyase-like (PLL) genes in Brassica rapa.

    Science.gov (United States)

    Jiang, Jingjing; Yao, Lina; Miao, Ying; Cao, Jiashu

    2013-11-01

    Pectate lyases (PL) depolymerize demethylated pectin (pectate, EC 4.2.2.2) by catalyzing the eliminative cleavage of α-1,4-glycosidic linked galacturonan. Pectate Lyase-like (PLL) genes are one of the largest and most complex families in plants. However, studies on the phylogeny, gene structure, and expression of PLL genes are limited. To understand the potential functions of PLL genes in plants, we characterized their intron-exon structure, phylogenetic relationships, and protein structures, and measured their expression patterns in various tissues, specifically the reproductive tissues in Brassica rapa. Sequence alignments revealed two characteristic motifs in PLL genes. The chromosome location analysis indicated that 18 of the 46 PLL genes were located in the least fractionated sub-genome (LF) of B. rapa, while 16 were located in the medium fractionated sub-genome (MF1) and 12 in the more fractionated sub-genome (MF2). Quantitative RT-PCR analysis showed that BrPLL genes were expressed in various tissues, with most of them being expressed in flowers. Detailed qRT-PCR analysis identified 11 pollen specific PLL genes and several other genes with unique spatial expression patterns. In addition, some duplicated genes showed similar expression patterns. The phylogenetic analysis identified three PLL gene subfamilies in plants, among which subfamily II might have evolved from gene neofunctionalization or subfunctionalization. Therefore, this study opens the possibility for exploring the roles of PLL genes during plant development.

  13. Characterization of pectin lyase produced by an endophytic strain isolated from coffee cherries.

    Science.gov (United States)

    Sakiyama, C C; Paula, E M; Pereira, P C; Borges, A C; Silva, D O

    2001-08-01

    The effect of endophytic bacterial activity on the quality of coffee beverage was studied. A survey of the micro-organisms in coffee cherries was performed before harvesting, and their growth on the main nutrients available in coffee cherries was determined in vitro. Many endophytic bacteria were isolated from surface-sterilized coffee cherries. One of the pectinolytic strains was physiologically and phenotypically characterized, and was tentatively identified by partial 16S rDNA sequencing as Paenibacillus amylolyticus. This endophytic strain produced an extracellular pectinase with maximal activity at 40 degrees C and pH 7.9, and was thermostable up to 45 degrees C. EDTA and metal ions had little effect on pectin lyase activity. Km and Vmax values were 4.6 mg ml(-1) and 94.0 10(-8) mol min(-1) ml(-1), respectively. Pectin lyases have been found in fungi but rarely in bacteria, and this isolate is a promising tool for regulation studies of these enzymes.

  14. Structural Basis for Streptogramin B Resistance in Staphylococcus aureus by Virginiamycin B Lyase

    Energy Technology Data Exchange (ETDEWEB)

    Korczynska,M.; Mukhtar, T.; Wright, G.; Berghuis, A.

    2007-01-01

    The streptogramin combination therapy of quinupristin-dalfopristin (Synercid) is used to treat infections caused by bacterial pathogens, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. However, the effectiveness of this therapy is being compromised because of an increased incidence of streptogramin resistance. One of the clinically observed mechanisms of resistance is enzymatic inactivation of the type B streptogramins, such as quinupristin, by a streptogramin B lyase, i.e., virginiamycin B lyase (Vgb). The enzyme catalyzes the linearization of the cyclic antibiotic via a cleavage that requires a divalent metal ion. Here, we present crystal structures of Vgb from S. aureus in its apoenzyme form and in complex with quinupristin and Mg{sup 2+} at 1.65- and 2.8-{angstrom} resolution, respectively. The fold of the enzyme is that of a seven-bladed {beta}-propeller, although the sequence reveals no similarity to other known members of this structural family. Quinupristin binds to a large depression on the surface of the enzyme, where it predominantly forms van der Waals interactions. Validated by site-directed mutagenesis studies, a reaction mechanism is proposed in which the initial abstraction of a proton is facilitated by a Mg{sup 2+}-linked conjugated system. Analysis of the Vgb-quinupristin structure and comparison with the complex between quinupristin and its natural target, the 50S ribosomal subunit, reveals features that can be exploited for developing streptogramins that are impervious to Vgb-mediated resistance.

  15. Modulation of Central Carbon Metabolism by Acetylation of Isocitrate Lyase in Mycobacterium tuberculosis

    Science.gov (United States)

    Bi, Jing; Wang, Yihong; Yu, Heguo; Qian, Xiaoyan; Wang, Honghai; Liu, Jun; Zhang, Xuelian

    2017-01-01

    Several enzymes involved in central carbon metabolism such as isocitrate lyase and phosphoenolpyruvate carboxykinase are key determinants of pathogenesis of Mycobacterium tuberculosis (M. tb). In this study, we found that lysine acetylation plays an important role in the modulation of central carbon metabolism in M. tb. Mutant of M. tb defective in sirtuin deacetylase exhibited improved growth in fatty acid-containing media. Global analysis of lysine acetylome of M. tb identified three acetylated lysine residues (K322, K331, and K392) of isocitrate lyase (ICL1). Using a genetically encoding system, we demonstrated that acetylation of K392 increased the enzyme activity of ICL1, whereas acetylation of K322 decreased its activity. Antibodies that specifically recognized acetyllysine at 392 and 322 of ICL1 were used to monitor the levels of ICL1 acetylation in M. tb cultures. The physiological significance of ICL1 acetylation was demonstrated by the observation that M. tb altered the levels of acetylated K392 in response to changes of carbon sources, and that acetylation of K392 affected the abundance of ICL1 protein. Our study has uncovered another regulatory mechanism of ICL1. PMID:28322251

  16. Structural basis for streptogramin B resistance in Staphylococcus aureus by virginiamycin B lyase.

    Science.gov (United States)

    Korczynska, Magdalena; Mukhtar, Tariq A; Wright, Gerard D; Berghuis, Albert M

    2007-06-19

    The streptogramin combination therapy of quinupristin-dalfopristin (Synercid) is used to treat infections caused by bacterial pathogens, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. However, the effectiveness of this therapy is being compromised because of an increased incidence of streptogramin resistance. One of the clinically observed mechanisms of resistance is enzymatic inactivation of the type B streptogramins, such as quinupristin, by a streptogramin B lyase, i.e., virginiamycin B lyase (Vgb). The enzyme catalyzes the linearization of the cyclic antibiotic via a cleavage that requires a divalent metal ion. Here, we present crystal structures of Vgb from S. aureus in its apoenzyme form and in complex with quinupristin and Mg2+ at 1.65- and 2.8-A resolution, respectively. The fold of the enzyme is that of a seven-bladed beta-propeller, although the sequence reveals no similarity to other known members of this structural family. Quinupristin binds to a large depression on the surface of the enzyme, where it predominantly forms van der Waals interactions. Validated by site-directed mutagenesis studies, a reaction mechanism is proposed in which the initial abstraction of a proton is facilitated by a Mg2+ -linked conjugated system. Analysis of the Vgb-quinupristin structure and comparison with the complex between quinupristin and its natural target, the 50S ribosomal subunit, reveals features that can be exploited for developing streptogramins that are impervious to Vgb-mediated resistance.

  17. [Characterization and properties of two dehydroquinate hydro-lyases in higher plants].

    Science.gov (United States)

    Boudet, A M; Lécussan, R; Boudet, A

    1975-01-01

    Two dehydroquinate hydro-lyases (E.C. 4.2.1.10) have been routinely separated from different organs of Zea mays L. by chromatography on Cellex-D Bio-Rad or hydroxypatite using linear salt gradients. Dehydroquinate hydro-lyase 1 is associated with shikimate: NADP(+) oxidoreductase (E.C. 1.1.1.25). DHQase 2 is a free constitutive enzyme; in this respect it differs from the inducible enzyme of microorganisms which appears only when dehydroquinate or quinate is the principal carbon source. DHQase 1 and DHQase 2 have a similar apparent Michaelis constant and pH optimum, but they differ in their molecular weight, thermal stability and sensitivity to metabolic effectors. DHQase 2 is specifically activated by shikimic acid. This strong activation and the channeling properties of the complex involved in the shikimate pathway can provide an effective means of control in the utilization of dehydroquinate between two different pathways. The significance of such a system involving both a specific regulation of isoenzymes and a molecular compartmentation by means of an enzymatic complex is discussed.

  18. Sugar-cane juice induces pectin lyase and polygalacturonase in Penicillium griseoroseum

    Directory of Open Access Journals (Sweden)

    Minussi Rosana Cristina

    1998-01-01

    Full Text Available The use of other inducers as substitutes for pectin was studied aiming to reduce the production costs of pectic enzymes. The effects of sugar-cane juice on the production of pectin lyase (PL and polygalacturonase (PG by Penicillium griseoroseum were investigated. The fungus was cultured in a mineral medium (pH 6.3 in a rotary shaker (150 rpm for 48 h at 25oC. Culture media were supplemented with yeast extract and sucrose or sugar-cane juice. Sugar-cane juice added singly to the medium promoted higher PL activity and mycelial dry weight when compared to pectin and the use of sugar-cane juice and yeast extract yielded levels of PG activity that were similar to those obtained with sucrose-yeast extract or pectin. The results indicated that, even at low concentrations, sugar-cane juice was capable of inducing pectin lyase and polygalacturonase with no cellulase activity in P. griseoroseum.

  19. Legionella pneumophila S1P-lyase targets host sphingolipid metabolism and restrains autophagy.

    Science.gov (United States)

    Rolando, Monica; Escoll, Pedro; Nora, Tamara; Botti, Joëlle; Boitez, Valérie; Bedia, Carmen; Daniels, Craig; Abraham, Gilu; Stogios, Peter J; Skarina, Tatiana; Christophe, Charlotte; Dervins-Ravault, Delphine; Cazalet, Christel; Hilbi, Hubert; Rupasinghe, Thusitha W T; Tull, Dedreia; McConville, Malcolm J; Ong, Sze Ying; Hartland, Elizabeth L; Codogno, Patrice; Levade, Thierry; Naderer, Thomas; Savchenko, Alexei; Buchrieser, Carmen

    2016-02-16

    Autophagy is an essential component of innate immunity, enabling the detection and elimination of intracellular pathogens. Legionella pneumophila, an intracellular pathogen that can cause a severe pneumonia in humans, is able to modulate autophagy through the action of effector proteins that are translocated into the host cell by the pathogen's Dot/Icm type IV secretion system. Many of these effectors share structural and sequence similarity with eukaryotic proteins. Indeed, phylogenetic analyses have indicated their acquisition by horizontal gene transfer from a eukaryotic host. Here we report that L. pneumophila translocates the effector protein sphingosine-1 phosphate lyase (LpSpl) to target the host sphingosine biosynthesis and to curtail autophagy. Our structural characterization of LpSpl and its comparison with human SPL reveals high structural conservation, thus supporting prior phylogenetic analysis. We show that LpSpl possesses S1P lyase activity that was abrogated by mutation of the catalytic site residues. L. pneumophila triggers the reduction of several sphingolipids critical for macrophage function in an LpSpl-dependent and -independent manner. LpSpl activity alone was sufficient to prevent an increase in sphingosine levels in infected host cells and to inhibit autophagy during macrophage infection. LpSpl was required for efficient infection of A/J mice, highlighting an important virulence role for this effector. Thus, we have uncovered a previously unidentified mechanism used by intracellular pathogens to inhibit autophagy, namely the disruption of host sphingolipid biosynthesis.

  20. Characterization of C-S Lyase from C. diphtheriae: A Possible Target for New Antimicrobial Drugs

    Directory of Open Access Journals (Sweden)

    Alessandra Astegno

    2013-01-01

    Full Text Available The emergence of antibiotic resistance in microbial pathogens requires the identification of new antibacterial drugs. The biosynthesis of methionine is an attractive target because of its central importance in cellular metabolism. Moreover, most of the steps in methionine biosynthesis pathway are absent in mammals, lowering the probability of unwanted side effects. Herein, detailed biochemical characterization of one enzyme required for methionine biosynthesis, a pyridoxal-5′-phosphate (PLP- dependent C-S lyase from Corynebacterium diphtheriae, a pathogenic bacterium that causes diphtheria, has been performed. We overexpressed the protein in E. coli and analyzed substrate specificity, pH dependence of steady state kinetic parameters, and ligand-induced spectral transitions of the protein. Structural comparison of the enzyme with cystalysin from Treponema denticola indicates a similarity in overall folding. We used site-directed mutagenesis to highlight the importance of active site residues Tyr55, Tyr114, and Arg351, analyzing the effects of amino acid replacement on catalytic properties of enzyme. Better understanding of the active site of C. diphtheriae C-S lyase and the determinants of substrate and reaction specificity from this work will facilitate the design of novel inhibitors as antibacterial therapeutics.

  1. Purification and Characterization of a New Alginate Lyase from Marine Bacterium Vibrio sp. SY08.

    Science.gov (United States)

    Li, Shangyong; Wang, Linna; Hao, Jianhua; Xing, Mengxin; Sun, Jingjing; Sun, Mi

    2016-12-23

    Unsaturated alginate disaccharides (UADs), enzymatically derived from the degradation of alginate polymers, are considered powerful antioxidants. In this study, a new high UAD-producing alginate lyase, AlySY08, has been purified from the marine bacterium Vibrio sp. SY08. AlySY08, with a molecular weight of about 33 kDa and a specific activity of 1070.2 U/mg, showed the highest activity at 40 °C in phosphate buffer at pH 7.6. The enzyme was stable over a broad pH range (6.0-9.0) and retained about 75% activity after incubation at 40 °C for 2 h. Moreover, the enzyme was active in the absence of salt ions and its activity was enhanced by the addition of NaCl and KCl. AlySY08 resulted in an endo-type alginate lyase that degrades both polyM and polyG blocks, yielding UADs as the main product (81.4% of total products). All these features made AlySY08 a promising candidate for industrial applications in the production of antioxidants from alginate polysaccharides.

  2. There is a Relationship between Resource Expenditures and Reference Transactions in Academic Libraries. A Review of: Dubnjakovic, A. (2012. Electronic resource expenditure and the decline in reference transaction statistics in academic libraries. Journal of Academic Librarianship, 38(2, 94-100. doi:10.1016/j.acalib.2012.01.001

    Directory of Open Access Journals (Sweden)

    Annie M. Hughes

    2013-03-01

    Full Text Available Objective – To provide an analysis of the impact of expenditures on electronic resourcesand gate counts on the increase or decrease in reference transactions.Design – Analysis of results of existing survey data from the National Center for Educational Statistics (NCES 2006 Academic Library Survey(ALS.Setting – Academic libraries in the United States.Subjects – 3925 academic library respondents.Methods – The author chose to use survey data collected from the 2006 ALS conducted bythe NCES. The survey included data on various topics related to academic libraries, but in the case of this study, the author chose to analyze three of the 193 variables included. The three variables: electronic books expenditure, computer hardware and software, and expenditures on bibliographic utilities, were combined into one variable called electronic resource expenditure. Gate counts were also considered as a variable. Electronic resource expenditure was also split as a variable into three groups: low, medium, and high. Multiple regression analysis and general linear modeling, along with tests of reliability, were employed. Main Results – The author determined that low, medium, and high spenders with regard to electronic resources exhibited differences in gate counts, and gate counts have an effect on reference transactions in any given week. Gate counts tend to not have much of an effect on reference transactions for the higher spenders, and higher spenders tend to have a higher number of reference transactions overall. Low spenders have lower gate counts and also a lower amount of reference transactions.Conclusion – The findings from this study show that academic libraries spending more on electronic resources also tend to have an increase with regard to reference transactions. The author also concludes that library spaces are no longer the determining factor with regard to number of reference transactions. Spending more on electronic resources is

  3. The Saccharomyces cerevisiae ICL2 Gene Encodes a Mitochondrial 2-Methylisocitrate Lyase Involved in Propionyl-Coenzyme A Metabolism

    NARCIS (Netherlands)

    Luttik, Marijke A.H.; Kötter, Peter; Salomons, Florian A.; Klei, Ida J. van der; Dijken, Johannes P. van; Pronk, Jack T.

    2000-01-01

    The Saccharomyces cerevisiae ICL1 gene encodes isocitrate lyase, an essential enzyme for growth on ethanol and acetate. Previous studies have demonstrated that the highly homologous ICL2 gene (YPR006c) is transcribed during the growth of wild-type cells on ethanol. However, even when multiple copies

  4. Molecular and Functional Analyses of the metC Gene of Lactococcus lactis, Encoding Cystathionine β-Lyase

    NARCIS (Netherlands)

    Fernández, María; Doesburg, Wim van; Rutten, Ger A.M.; Marugg, Joey D.; Alting, Arno C.; Kranenburg, Richard van; Kuipers, Oscar P.

    2000-01-01

    The enzymatic degradation of amino acids in cheese is believed to generate aroma compounds and therefore to be essential for flavor development. Cystathionine β-lyase (CBL) can convert cystathionine to homocysteine but is also able to catalyze an α,γ elimination. With methionine as a substrate, it p

  5. Characterization of an extracellular biofunctional alginate lyase from marine Microbulbifer sp. ALW1 and antioxidant activity of enzymatic hydrolysates.

    Science.gov (United States)

    Zhu, Yanbing; Wu, Liyun; Chen, Yanhong; Ni, Hui; Xiao, Anfeng; Cai, Huinong

    2016-01-01

    A novel alginate-degrading marine bacterium Microbulbifer sp. ALW1 was isolated from rotten brown alga. An extracellular alginate lyase was purified to electrophoretic homogeneity and had a molecular mass of about 26.0 kDa determined by SDS-PAGE and size exclusion chromatography. This enzyme showed activities towards both polyguluronate and polymannuronate indicating its bifunctionality while with preference for the former substrate. Using sodium alginate as a substrate, strain ALW1 alginate lyase was optimally active at 45 °C and pH 7.0. It was stable at 25 °C, 30 °C, 35 °C and 40 °C, but not stable at 50 °C. This alginate lyase showed good stability over a broad pH range (5.0-9.0). The enzyme activity was increased to 5.1 times by adding NaCl to a final concentration of 0.5M. Strain ALW1 alginate lyase produced disaccharide (majority) and trisaccharide from alginate indicating that this enzyme could be a good tool for preparation of alginate oligosaccharides with low degree of polymerization (DP). The alginate oligosaccharides displayed the scavenging abilities towards radicals (DPPH, ABTS(+) and hydroxyl) and the reducing power. Therefore, the hydrolysates exhibited the antioxidant activity and had potential as a natural antioxidant.

  6. Possible regulatory role of phenylalanine ammonia-lyase in the production of anthocyanins in asparagus (Asparagus officinalis L)

    NARCIS (Netherlands)

    Flores, F.B.; Oosterhaven, J.; Martinez-Madrid, M.C.; Romojaro, F.

    2005-01-01

    The regulatory role of phenylalanine ammonia-lyase (PAL) in the light-induced accumulation of anthocyanins in the epidermis of asparagus spears has been analysed. A correlation between the stimulation of PAL activity and the rise in total anthocyanin content has been observed. Light radiation induce

  7. Crystallization and preliminary X-ray crystallographic studies of the ArsI C–As lyase from Thermomonospora curvata

    Energy Technology Data Exchange (ETDEWEB)

    Nadar, S. Venkadesh; Yoshinaga, Masafumi; Kandavelu, Palani; Sankaran, Banumathi; Rosen, Barry P., E-mail: brosen@fiu.edu

    2014-05-10

    The ArsI C-As lyase from Thermomonospora curvata was expressed, purified and crystallized. The crystals diffracted to 1.46 Å and belong to space group P4{sub 3}2{sub 1}2 or its enantiomer P4{sub 1}2{sub 1}2.

  8. Probing the Active Center of Benzaldehyde Lyase with Substitutions and the Pseudosubstrate Analogue Benzoylphosphonic Acid Methyl Ester

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Gabriel S.; Nemeria, Natalia; Chakraborty, Sumit; McLeish, Michael J.; Yep, Alejandra; Kenyon, George L.; Petsko, Gregory A.; Jordan, Frank; Ringe, Dagmar (Rutgers); (Michigan); (Brandeis)

    2008-07-28

    Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of (R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg{sup 2+} as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these types of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analogue of benzoylformic acid, is used to probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 {angstrom} (Protein Data Bank entry 3D7K) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase.

  9. Five phosphonate operon gene products as components of a multi-subunit complex of the carbon-phosphorus lyase pathway

    DEFF Research Database (Denmark)

    Jochimsen, Bjarne; Lolle, Signe; McSorley, Fern R.;

    2011-01-01

    Organophosphonate utilization by Escherichia coli requires the 14 cistrons of the phnCDEFGHIJKLMNOP operon, of which the carbon-phosphorus lyase has been postulated to consist of the seven polypeptides specified by phnG to phnM. A 5,660-bp DNA fragment encompassing phnGHIJKLM is cloned, followed ...

  10. Possible regulatory role of phenylalanine ammonia-lyase in the production of anthocyanins in asparagus (Asparagus officinalis L)

    NARCIS (Netherlands)

    Flores, F.B.; Oosterhaven, J.; Martinez-Madrid, M.C.; Romojaro, F.

    2005-01-01

    The regulatory role of phenylalanine ammonia-lyase (PAL) in the light-induced accumulation of anthocyanins in the epidermis of asparagus spears has been analysed. A correlation between the stimulation of PAL activity and the rise in total anthocyanin content has been observed. Light radiation induce

  11. Purification and Characterization of a Unique Pectin Lyase from Aspergillus giganteus Able to Release Unsaturated Monogalacturonate during Pectin Degradation.

    Science.gov (United States)

    Pedrolli, Danielle Biscaro; Carmona, Eleonora Cano

    2014-01-01

    A pectin lyase, named PLIII, was purified to homogeneity from the culture filtrate of Aspergillus giganteus grown in submerged culture containing orange peel waste as carbon source. PLIII was able to digest apple pectin and citrus pectins with different degrees of methyl esterification. Interestingly, the PLIII activity was stimulated in the presence of some divalent cations including Pb(2+) and was not significantly affected by Hg(2+). Like other pectin lyases, PLIII is stimulated by but is not dependent on Ca(2+). The main soluble product released during the degradation of pectic substances promoted by the PLIII is compatible with an unsaturated monogalacturonate. PLIII is a unique enzyme able to release unsaturated monogalacturonate as the only soluble product during the degradation of pectic substances; therefore, PLIII was classified as an exo-pectin lyase. To our knowledge, this is the first characterization of an exo-pectin lyase. The PLIII described in this work is potentially useful for ethanol production from pectin-rich biomass, besides other common applications for alkaline pectinases like preparation of textile fibers, coffee and tea fermentation, vegetable oil extraction, and the treatment of pulp in papermaking.

  12. Possible regulatory role of phenylalanine ammonia-lyase in the production of anthocyanins in asparagus (Asparagus officinalis L)

    NARCIS (Netherlands)

    Flores, F.B.; Oosterhaven, J.; Martinez-Madrid, M.C.; Romojaro, F.

    2005-01-01

    The regulatory role of phenylalanine ammonia-lyase (PAL) in the light-induced accumulation of anthocyanins in the epidermis of asparagus spears has been analysed. A correlation between the stimulation of PAL activity and the rise in total anthocyanin content has been observed. Light radiation

  13. A 5-methylcytosine DNA glycosylase/lyase demethylates the retrotransposon Tos17 and promotes its transposition in rice

    KAUST Repository

    La, Honggui

    2011-09-06

    DNA 5-methylcytosine (5-meC) is an important epigenetic mark for transcriptional gene silencing in many eukaryotes. In Arabidopsis, 5-meC DNA glycosylase/lyases actively remove 5-meC to counter-act transcriptional gene silencing in a locus-specific manner, and have been suggested to maintain the expression of transposons. However, it is unclear whether plant DNA demethylases can promote the transposition of transposons. Here we report the functional characterization of the DNA glycosylase/lyase DNG701 in rice. DNG701 encodes a large (1,812 amino acid residues) DNA glycosylase domain protein. Recombinant DNG701 protein showed 5-meC DNA glycosylase and lyase activities in vitro. Knockout or knockdown of DNG701 in rice plants led to DNA hypermethylation and reduced expression of the retrotransposon Tos17. Tos17 showed less transposition in calli derived from dng701 knockout mutant seeds compared with that in wild-type calli. Overexpression of DNG701 in both rice calli and transgenic plants substantially reduced DNA methylation levels of Tos17 and enhanced its expression. The overexpression also led to more frequent transposition of Tos17 in calli. Our results demonstrate that rice DNG701 is a 5-meC DNA glycosylase/lyase responsible for the demethylation of Tos17 and this DNA demethylase plays a critical role in promoting Tos17 transposition in rice calli.

  14. Probing the active center of benzaldehyde lyase with substitutions and the pseudosubstrate analogue benzoylphosphonic acid methyl ester.

    Science.gov (United States)

    Brandt, Gabriel S; Nemeria, Natalia; Chakraborty, Sumit; McLeish, Michael J; Yep, Alejandra; Kenyon, George L; Petsko, Gregory A; Jordan, Frank; Ringe, Dagmar

    2008-07-22

    Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of ( R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg (2+) as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these types of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analogue of benzoylformic acid, is used to probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 A (Protein Data Bank entry 3D7K ) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase.

  15. Purification and Characterization of a Unique Pectin Lyase from Aspergillus giganteus Able to Release Unsaturated Monogalacturonate during Pectin Degradation

    Directory of Open Access Journals (Sweden)

    Danielle Biscaro Pedrolli

    2014-01-01

    Full Text Available A pectin lyase, named PLIII, was purified to homogeneity from the culture filtrate of Aspergillus giganteus grown in submerged culture containing orange peel waste as carbon source. PLIII was able to digest apple pectin and citrus pectins with different degrees of methyl esterification. Interestingly, the PLIII activity was stimulated in the presence of some divalent cations including Pb2+ and was not significantly affected by Hg2+. Like other pectin lyases, PLIII is stimulated by but is not dependent on Ca2+. The main soluble product released during the degradation of pectic substances promoted by the PLIII is compatible with an unsaturated monogalacturonate. PLIII is a unique enzyme able to release unsaturated monogalacturonate as the only soluble product during the degradation of pectic substances; therefore, PLIII was classified as an exo-pectin lyase. To our knowledge, this is the first characterization of an exo-pectin lyase. The PLIII described in this work is potentially useful for ethanol production from pectin-rich biomass, besides other common applications for alkaline pectinases like preparation of textile fibers, coffee and tea fermentation, vegetable oil extraction, and the treatment of pulp in papermaking.

  16. Characterization of C-S lyase from Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 and its potential role in food flavour applications.

    Science.gov (United States)

    Allegrini, Alessandra; Astegno, Alessandra; La Verde, Valentina; Dominici, Paola

    2016-12-21

    Volatile thiols have substantial impact on the aroma of many beverages and foods. Thus, the control of their formation, which has been linked to C-S lyase enzymatic activities, is of great significance in industrial applications involving food flavours. Herein, we have carried out a spectroscopic and functional characterization of a putative pyridoxal 5'-phosphate (PLP)-dependent C-S lyase from the lactic acid bacterium Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 (LDB C-S lyase). Recombinant LDB C-S lyase exists as a tetramer in solution and shows spectral properties of enzymes containing PLP as cofactor. The enzyme has a broad substrate specificity toward sulphur-containing amino acids with aminoethyl-L-cysteine and L-cystine being the most effective substrates over L-cysteine and L-cystathionine. Notably, the protein also reveals cysteine-S-conjugate β-lyase activity in vitro, and is able to cleave a cysteinylated substrate precursor into the corresponding flavour-contributing thiol, with a catalytic efficiency higher than L-cystathionine. Contrary to similar enzymes of other lactic acid bacteria however, LDB C-S lyase is not capable of α,γ-elimination activity towards L-methionine to produce methanethiol, which is a significant compound in flavour development. Based on our results, future developments can be expected regarding the flavour-forming potential of Lactobacillus C-S lyase and its use in enhancing food flavours.

  17. Activities of methionine-γ-lyase in the acidophilic archaeon “Ferroplasma acidarmanus” strain fer1

    Directory of Open Access Journals (Sweden)

    Khan MA

    2013-04-01

    Full Text Available M A Khan,1 Madeline M López-Muñoz,2 Charles W Kaspar,3 Kai F Hung1 1Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA; 2Department of Biology, Universidad de Puerto Rico, Mayaguez, Puerto Rico; 3Bacteriology Department, University of Wisconsin, Madison, WI, USA Abstract: Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1's ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine-γ-lyase (EC 4.4.1.11, an enzyme known to carry out α, γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5'-phosphate (PLP binding domain and a partially conserved catalytic domain in both putative sequences. Detection of PLP-dependent and L-methionine-dependent production of α-keto compounds and thiol groups in fer1 confirmed the presence of methionine-γ-lyase activity. Further, fer1 lysate was capable of processing related substrates, including D-methionine, L-cysteine, L-cystathionine, and L/D-homocysteine. When the two putative fer1 methionine-γ-lyase gene-coded proteins were expressed in Escherichia coli cells, one sequence demonstrated an ability to carry out α, γ-elimination activity, while the other exhibited γ-replacement activity. These fer1 methionine-γ-lyases also exhibited optimum pH, substrate specificity, and catalytic preferences that are different from methionine-γ-lyases from other organisms. These differences are discussed in the context of molecular phylogeny constructed using a maximum

  18. cDNA cloning and bacterial expression of a PL-14 alginate lyase from a herbivorous marine snail Littorina brevicula.

    Science.gov (United States)

    Rahman, Mohammad Matiur; Wang, Ling; Inoue, Akira; Ojima, Takao

    2012-10-01

    Herbivorous marine snails like Littorina species are known to possess alginate lyases in their digestive tracts. The Littorina enzymes have been identified as endolytic polymannuronate (poly(M)) lyases (EC 4.2.2.3); however, it is still unclear which polysaccharide-lyase family (PL) the Littorina enzymes belong to, since no complete primary structure of Littorina enzymes has been determined. Thus, in the present study, we analyzed the primary structure of LbAly28, a 28kDa alginate lyase isozyme of Littorina brevicula, by the cDNA method. LbAly28 cDNAs were amplified by PCR followed by 5'- and 3'-RACE PCRs from the L. brevicula hepatopancreas cDNA. A cDNA covering entire coding region of LbAly28 consisted of 1129bp and encoded an amino-acid sequence of 291 residues. The deduced amino-acid sequence comprised an initiation methionine, a putative signal peptide of 14 residues, a propeptide-like region of 16 residues, and a mature LbAly28 domain of 260 residues. The mature LbAly28 domain showed 43-53% amino-acid identities with other molluscan PL-14 enzymes. The catalytically important residues in PL-14 enzymes, which were identified in the Chlorella virus glucuronate-specific lyase vAL-1 and Aplysia poly(M) lyase AkAly30, were also conserved in LbAly28. Site-directed mutagenesis regarding these residues, that is, replacements of Lys94, Lys97, Thr121, Arg 123, Tyr135, and Tyr137 to Ala, decreased the activity of recombinant LbAly28 to various degrees. From these results we concluded that LbAly28 is a member of PL-14 alginate lyases. Besides the effects of above mutations, we noticed that the replacement of T121 by Ala changed the substrate preference of LbAly28. Namely, the activities toward sodium alginate and poly(MG)-block substrate increased and became comparable with the activity toward poly(M)-block substrate. This suggests that the region including T121 of LbAly28 closely relates to the recognition of poly(MG) region of alginate.

  19. If Information Wants To Be Free...Then Who's Going To Pay for It? [and] A Question of Access: SPARC, BioOne, and Society-Driven Electronic Publishing [and] Who Is Going To Mine Digital Library Resources? And How?

    Science.gov (United States)

    Kaser, Richard T.; Johnson, Richard K.; Rudner, Lawrence

    2000-01-01

    Discusses Fair Use and the public perception; models for funding information services; publishers illusion that information is/should be free; Internet's role in making information freely available; scholarly communication systems: Scholarly Publishing and Academic Resources Coalition (SPARC) and BioOne (an electronic aggregation of bioscience…

  20. If Information Wants To Be Free...Then Who's Going To Pay for It? [and] A Question of Access: SPARC, BioOne, and Society-Driven Electronic Publishing [and] Who Is Going To Mine Digital Library Resources? And How?

    Science.gov (United States)

    Kaser, Richard T.; Johnson, Richard K.; Rudner, Lawrence

    2000-01-01

    Discusses Fair Use and the public perception; models for funding information services; publishers illusion that information is/should be free; Internet's role in making information freely available; scholarly communication systems: Scholarly Publishing and Academic Resources Coalition (SPARC) and BioOne (an electronic aggregation of bioscience…

  1. Impact of two interventions on timeliness and data quality of an electronic disease surveillance system in a resource limited setting (Peru: a prospective evaluation

    Directory of Open Access Journals (Sweden)

    Quispe Jose A

    2009-03-01

    Full Text Available Abstract Background A timely detection of outbreaks through surveillance is needed in order to prevent future pandemics. However, current surveillance systems may not be prepared to accomplish this goal, especially in resource limited settings. As data quality and timeliness are attributes that improve outbreak detection capacity, we assessed the effect of two interventions on such attributes in Alerta, an electronic disease surveillance system in the Peruvian Navy. Methods 40 Alerta reporting units (18 clinics and 22 ships were included in a 12-week prospective evaluation project. After a short refresher course on the notification process, units were randomly assigned to either a phone, visit or control group. Phone group sites were called three hours before the biweekly reporting deadline if they had not sent their report. Visit group sites received supervision visits on weeks 4 & 8, but no phone calls. The control group sites were not contacted by phone or visited. Timeliness and data quality were assessed by calculating the percentage of reports sent on time and percentage of errors per total number of reports, respectively. Results Timeliness improved in the phone group from 64.6% to 84% in clinics (+19.4 [95% CI, +10.3 to +28.6]; p Conclusion Regular phone reminders significantly improved timeliness of reports in clinics and ships, whereas supervision visits led to improved data quality only among clinics. Further investigations are needed to establish the cost-effectiveness and optimal use of each of these strategies.

  2. Metadata for Electronic Information Resources

    Science.gov (United States)

    2004-12-01

    among digital libraries . METS provides an XML DTD that can point to metadata in other schemes by declaring the scheme that is being used. For example...site: www.niso.org/news/Metadata_simpler.pdf International Federation of Library Associations and Institutions (IFLA). (2002). Digital Libraries : Metadata

  3. 基于ASP.NET的电子资源整合系统设计与实现%Design and Realization of an Integrated Electronic Resource System Based on ASP.NET

    Institute of Scientific and Technical Information of China (English)

    冀宪武; 陈晓冬; 何燕; 杨方; 曹宇宾; 潘大丰

    2011-01-01

    电子信息资源的整合是数字图书馆建设中的一个非常重要的环节,论述了数字资源整合的必要性,结合农业图书馆的实际,开展了电子资源整合服务平台的设计与实现。%The integration of electronic information resources is a very important part in digital library construction.In this paper,the necessity for integration of digital resources was discussed,combined with the actuality of the agricultural library,the design and implementation about services platform of electronic resource integration were carried out.

  4. Inhibition of the cystathionine-γ-lyase/hydrogen sulfide pathway in rat vascular smooth muscle cells by cobalt-60 gamma radiation

    Institute of Scientific and Technical Information of China (English)

    ZHONG Guang-zhen; YANG Xin-chun; JIA Li-ping; CHEN Feng-rong; CUI Ming

    2009-01-01

    Background Radiation is a promising treatment for in stent restenosis and restenosis following percutaneous transluminal coronary angioplasty, which has troubled interventional cardiologists for a long time. It inhibits neointima hyperplasia, vascular remodeling, and increases the mean luminal diameter. The mechanism of intracoronary brachytherapy for restenosis is not well understood. Endogenous gaseous transmitters including nitric oxide and carbon monoxide are closely related to restenosis. Hydrogen sulfide, a new endogenous gaseous transmitter, is able to inhibit the proliferation of vascular smooth muscle cells and vascular remodeling. This study aimed to clarify the effect of radiation on cystathionine-y-lyase/hydrogen sulfide pathway in rat smooth muscle cells.Methods We studied the effect of radiation on the cystathionine-γ-lyase/hydrogen sulfide pathway. Rat vascular smooth muscle cells were radiated with 60Co y at doses of 14 Gy and 25 Gy respectively. Then the mRNA level of cystathionine-γ-lyase was studied by quantitative reverse-transcription competitive polymerase chain reaction. Hydrogen sulfide concentration in culture medium was determined by methylene blue spectrophotometry. Cystathionine-γ-lyase activity in vascular smooth muscle cells was also studied.Results 60Co y radiation at a dose of 1 Gy did not affect the cystathionine-γ-lyase/hydrogen sulfide pathway significantly. However, 60Co y radiation at doses of 14 Gy and 25 Gy decreased the hydrogen sulfide synthesis by 21.9% (P <0.05) and 26.8% (P <0.01 ) respectively. At the same time, they decreased the cystathionine-γ-lyase activity by 15.1% (P <0.05) and 20.5% (P <0.01) respectively, and cystathionine-γ-lyase mRNA expression by 29.3% (P <0.01 ) and 38.2% (P <0.01) respectively.Conclusion Appropriate 60Co γ radiation inhibits the H2S synthesis by inhibiting the gene expression of cystathionine-γ-lyase and the cystathionine-y-lyase activity.

  5. Active site proton delivery and the lyase activity of human CYP17A1

    Energy Technology Data Exchange (ETDEWEB)

    Khatri, Yogan; Gregory, Michael C.; Grinkova, Yelena V.; Denisov, Ilia G.; Sligar, Stephen G., E-mail: s-sligar@illinois.edu

    2014-01-03

    Highlights: •The disruption of PREG/PROG hydroxylation activity by T306A showed the participation of Cpd I. •T306A supports the involvement of a nucleophilic peroxo-anion during lyase activity. •The presence of cytochrome b{sub 5} augments C–C lyase activity. •Δ5-Steroids are preferred substrates for CYP17 catalysis. -- Abstract: Cytochrome P450 CYP17A1 catalyzes a series of reactions that lie at the intersection of corticoid and androgen biosynthesis and thus occupies an essential role in steroid hormone metabolism. This multifunctional enzyme catalyzes the 17α-hydroxylation of Δ4- and Δ5-steroids progesterone and pregnenolone to form the corresponding 17α-hydroxy products through its hydroxylase activity, and a subsequent 17,20-carbon–carbon scission of pregnene-side chain produce the androgens androstenedione (AD) and dehydroepiandrosterone (DHEA). While the former hydroxylation reaction is believed to proceed through a conventional “Compound I” rebound mechanism, it has been suggested that the latter carbon cleavage is initiated by an iron-peroxy intermediate. We report on the role of Thr306 in CYP17 catalysis. Thr306 is a member of the conserved acid/alcohol pair thought to be essential for the efficient delivery of protons required for hydroperoxoanion heterolysis and formation of Compound I in the cytochromes P450. Wild type and T306A CYP17A1 self-assembled in Nanodiscs were used to quantitate turnover and coupling efficiencies of CYP17’s physiological Δ4- and Δ5-substrates. We observed that T306A co-incorporated in Nanodiscs with its redox partner cytochrome P450 oxidoreductase, coupled NADPH only by 0.9% and 0.7% compared to the wild type (97% and 22%) during the conversion of pregnenolone and progesterone, respectively, to the corresponding 17-OH products. Despite increased oxidation of pyridine nucleotide, hydroxylase activity was drastically diminished in the T306A mutant, suggesting a high degree of uncoupling in which reducing

  6. Rapid induction of the synthesis of phenylalanine ammonia-lyase and of chalcone synthase in elicitor-treated plant cells.

    Science.gov (United States)

    Lawton, M A; Dixon, R A; Hahlbrock, K; Lamb, C

    1983-01-01

    Changes in the rate of synthesis of phenylalanine ammonia-lyase and chalcone synthase, two characteristic enzymes of phenylpropanoid biosynthesis, have been investigated by direct immunoprecipitation of in vivo [35S]methionine-labelled enzyme subunits in elicitor-treated cells of dwarf French bean (Phaseolus vulgaris). Elicitor, heat-released from cell walls of Colletotrichum lindemuthianum, the causal agent of anthracnose disease of bean, causes marked but transient increases in the rates of synthesis of both enzymes concomitant with the phase of rapid increase in enzyme activity at the onset of phaseollin accumulation during the phytoalexin defence response. Increased rates of synthesis of both enzymes can be observed 20 min after elicitor treatment and the pattern of induction of synthesis of phenylalanine ammonia-lyase and chalcone synthase are broadly similar with respect to elicitor concentration and time, maximum rates of synthesis being attained between 2.5 h and 3.0 h after elicitor treatment. Within this overall co-ordination small but distinct differences between the enzymes were observed in: (a) the elicitor concentrations giving maximum enzyme synthesis, and (b) the precise timing of maximum enzyme synthesis, with that for chalcone synthase occurring 20-30 min earlier than that for phenylalanine ammonia-lyase. However, for a given rate of enzyme synthesis, induction of the activities of phenylalanine ammonia-lyase and chalcone synthase is more efficient at high elicitor concentrations. This may reflect the operation under certain circumstances of post-translational control of the activity levels of these enzymes as implicated for phenylalanine ammonia-lyase by previous density-labelling experiments [Lawton et al. (1980) Biochim. Biophys. Acta, 633, 162-175]. The same pattern of induction of enzyme synthesis is observed with elicitor preparations from a variety of sources.

  7. Library resources on the Internet

    Science.gov (United States)

    Buchanan, Nancy L.

    1995-07-01

    Library resources are prevalent on the Internet. Library catalogs, electronic books, electronic periodicals, periodical indexes, reference sources, and U.S. Government documents are available by telnet, Gopher, World Wide Web, and FTP. Comparatively few copyrighted library resources are available freely on the Internet. Internet implementations of library resources can add useful features, such as full-text searching. There are discussion lists, Gophers, and World Wide Web pages to help users keep up with new resources and changes to existing ones. The future will bring more library resources, more types of library resources, and more integrated implementations of such resources to the Internet.

  8. Mini-review: recent developments in hydroxynitrile lyases for industrial biotechnology.

    Science.gov (United States)

    Lanfranchi, Elisa; Steiner, Kerstin; Glieder, Anton; Hajnal, Ivan; Sheldon, Roger A; van Pelt, Sander; Winkler, Margit

    2013-12-01

    Hydroxynitrile lyases (HNLs) catalyze the cleavage as well as the formation of cyanohydrins. The latter reaction is valuable for the stereoselective C-C bond formation by condensation of HCN with carbonyl compounds. The resulting cyanohydrins serve as versatile building blocks for a broad range of chemical and enzymatic follow-up reactions. A significant number of (R)- and (S)-selective HNLs are known today and the number is still increasing. HNLs not only exhibit varying substrate scope but also differ in sequence and structure. Tailor-made enzymes for large-scale manufacturing of cyanohydrins with improved yield and enantiomeric excess are very interesting targets, which is reflected in a solid number of patents. This review will complement and extend our recent review with a strong focus on applications of HNLs for the synthesis of highly functionalized, chiral compounds with newest literature, recent and current patent literature.

  9. Watermelon (Citrullus lanatus) hydroperoxide lyase greatly increases C6 aldehyde formation in transgenic leaves.

    Science.gov (United States)

    Fukushige, Hirotada; Hildebrand, David F

    2005-03-23

    Fatty acid hydroperoxide lyase (HL) is the key enzyme for the production of the "green note"compounds, leaf aldehyde [(2E)-hexenal] and leaf alcohol [(3Z)-hexenol], in plant tissues. A cDNA encoding HL was cloned from leaves of watermelon (Citrullus lanatus) and expressed in Nicotiana tabacum. The enzyme is 3 times more active with 13-hydroperoxylinolenic acid than with 13-hydroperoxylinoleic acid. The activity against 9-hydroperoxides of polyunsaturated fatty acids is minimal. Enzyme activity of the watermelon HL in the transgenic leaves was approximately 50 times higher than endogenous HL activity in the wild-type N. tabacum plants. When compared with Arabidopsis HL also expressed in N. tabacum, the highest HL activity is 10 times higher in watermelon HL overexpressing leaves than in Arabidopsis HL overexpressers.

  10. Gene deletion of cytosolic ATP: citrate lyase leads to altered organic acid production in Aspergillus niger

    DEFF Research Database (Denmark)

    Meijer, Susan Lisette; Nielsen, Michael Lynge; Olsson, Lisbeth

    2009-01-01

    With the availability of the genome sequence of the filamentous fungus Aspergillus niger, the use of targeted genetic modifications has become feasible. This, together with the fact that A. niger is well established industrially, makes this fungus an attractive micro-organism for creating a cell...... factory platform for production of chemicals. Using molecular biology techniques, this study focused on metabolic engineering of A. niger to manipulate its organic acid production in the direction of succinic acid. The gene target for complete gene deletion was cytosolic ATP: citrate lyase (acl), which...... the acl gene. Additionally, the total amount of organic acids produced in the deletion strain was significantly increased. Genome-scale stoichiometric metabolic model predictions can be used for identifying gene targets. Deletion of the acl led to increased succinic acid production by A. niger....

  11. Probing reversible chemistry in coenzyme B12 -dependent ethanolamine ammonia lyase with kinetic isotope effects.

    Science.gov (United States)

    Jones, Alex R; Rentergent, Julius; Scrutton, Nigel S; Hay, Sam

    2015-06-08

    Coenzyme B12 -dependent enzymes such as ethanolamine ammonia lyase have remarkable catalytic power and some unique properties that enable detailed analysis of the reaction chemistry and associated dynamics. By selectively deuterating the substrate (ethanolamine) and/or the β-carbon of the 5'-deoxyadenosyl moiety of the intrinsic coenzyme B12 , it was possible to experimentally probe both the forward and reverse hydrogen atom transfers between the 5'-deoxyadenosyl radical and substrate during single-turnover stopped-flow measurements. These data are interpreted within the context of a kinetic model where the 5'-deoxyadenosyl radical intermediate may be quasi-stable and rearrangement of the substrate radical is essentially irreversible. Global fitting of these data allows estimation of the intrinsic rate constants associated with CoC homolysis and initial H-abstraction steps. In contrast to previous stopped-flow studies, the apparent kinetic isotope effects are found to be relatively small.

  12. Expression in E. coli of the gene encoding phenylalanine ammonia-lyase from Rhodosporidium toruloides.

    Science.gov (United States)

    Orum, H; Rasmussen, O F

    1992-03-01

    The active sites of the enzyme phenylalanine ammonia-lyase (Pal) from Rhodosporidium toruloides contains a dehydroalanine residue that is believed to be essential for catalytic activity. Furthermore, the dehydroalanine is believed to be added post-translationally as part of a prosthetic group covalently attached to the enzyme. Perhaps for this reason no attempts to produce Pal in foreign host cells have been reported. We have inserted the entire uninterupted pal gene from R. toruloides into the Escherichia coli expression vector pKK 223-3. E. coli cells containing this vector synthesize a protein of the expected size, and extracts prepared from these cells contain a Pal-like activity. The potential implications of this finding are discussed.

  13. Paraffin as oxygen vector modulates tyrosine phenol lyase production by Citrobacter freundii MTCC 2424.

    Science.gov (United States)

    Azmi, Wamik; Kumar, Ajay; Dev, Varun

    2013-06-01

    The efficiency of three oxygen-vectors liquid paraffin, silicone oil and n-dodecane in the production of tyrosine phenol lyase (TPL) by Citrobacter freundii MTCC 2424 was evaluated at 4% (v/v) concentration. The liquid paraffin as oxygenvectors was found to exhibit a stimulatory effect on TPL synthesis. The liquid paraffin at 6% (v/v) resulted in 34% increase in the TPL synthesis accompanied by a 13% increase in the production of cell mass at a 10 L scale. This improvement in TPL and cell mass production in the presence of liquid paraffin can be related to the fact that liquid paraffin was capable of maintaining dissolved O2 concentration above 28% throughout the course of the fermentation. Maintenance of the dissolved O2 concentration above 28% could be viewed in terms of an adequate oxygen supply to the rapidly dividing cells of the bacterium, which in turn resulted in enhanced synthesis of TPL and cell mass.

  14. Protein packing interactions and polymorphy of chorismate lyase from E. Coli

    Science.gov (United States)

    Gallagher, Travis

    2001-11-01

    The enzyme chorismate lyase from E. coli crystallizes into three well characterized polymorphs in identical conditions. The Wild-type enzyme tends to aggregate, even in the presence of a reducing agent, and yields monoclinic crystals that grow in intricate clusters. Protein aggregation was largely eliminated by mutating the protein's two cysteines to serines. The double mutant retains full enzymatic activity and grows singly in two new forms: triclinic and orthorhombic. The triclinic crystals diffract to 0.9 Å resolution. A single-cysteine mutant that crystallizes in the orthorhombic form was used to determine the structure, enabling examination of the packing interactions at 2.0 Å resolution or better in all three forms. A novel system for labeling contacts is proposed, and relations between packing patterns and crystal properties are discussed. Diffraction resolution is found to correlate with coordination number and with the root-mean-square deviation from mean extent of the contacts. Implications for contact energies are considered.

  15. An acidic pectin lyase from Aspergillus niger with favourable efficiency in fruit juice clarification.

    Science.gov (United States)

    Xu, S X; Qin, X; Liu, B; Zhang, D Q; Zhang, W; Wu, K; Zhang, Y H

    2015-02-01

    The pectin lyase gene pnl-zj5a from Aspergillus niger ZJ5 was identified and expressed in Pichia pastoris. PNL-ZJ5A was purified by ultrafiltration, anion exchange and gel chromatography. The Km and Vmax values determined using citrus pectin were 0.66 mg ml(-1) and 32.6 μmol min(-1) mg(-1) , respectively. PNL-ZJ5A exhibited optimal activity at 43°C and retained activity over 25-50°C. PNL-ZJ5A was optimally active at pH 5 and effective in apple juice clarification. Compared with controls, PNL-ZJ5A increased the fruit juice yield significantly. Furthermore, PNL-ZJ5A reduced the viscosity of apple juice by 38.8% and increased its transmittance by 86.3%. PNL-ZJ5A combined with a commercial pectin esterase resulted in higher juice volume.

  16. Enhancing Production of Alkaline Polygalacturonate Lyase from Bacillus subtilis by Fed-Batch Fermentation

    Science.gov (United States)

    Zou, Mouyong; Guo, Fenfen; Li, Xuezhi; Zhao, Jian; Qu, Yinbo

    2014-01-01

    Alkaline polygalacturonate lyase (PGL, EC 4.2.2.2) is an enzyme used in many industries. We developed a fed-batch fermentation process that combines the enzymatic pretreatment of the carbon source with controlling the pH of the fermentative broth to enhance the PGL production from Bacillus subtilis 7-3-3 to decrease the production cost. Maintaining the fermentation broth at pH 6.5 prior to feeding with ammonia and at pH 6.0 after feeding significantly improved PGL activity (743.5 U mL−1) compared with the control (202.5 U mL−1). The average PGL productivity reached 19.6 U mL−1 h−1 after 38 h of fermentation. The crude PGL was suitable for environmentally friendly ramie enzymatic degumming. PMID:24603713

  17. Enzyme discovery beyond homology: a unique hydroxynitrile lyase in the Bet v1 superfamily

    Science.gov (United States)

    Lanfranchi, Elisa; Pavkov-Keller, Tea; Koehler, Eva-Maria; Diepold, Matthias; Steiner, Kerstin; Darnhofer, Barbara; Hartler, Jürgen; van den Bergh, Tom; Joosten, Henk-Jan; Gruber-Khadjawi, Mandana; Thallinger, Gerhard G.; Birner-Gruenberger, Ruth; Gruber, Karl; Winkler, Margit; Glieder, Anton

    2017-05-01

    Homology and similarity based approaches are most widely used for the identification of new enzymes for biocatalysis. However, they are not suitable to find truly novel scaffolds with a desired function and this averts options and diversity. Hydroxynitrile lyases (HNLs) are an example of non-homologous isofunctional enzymes for the synthesis of chiral cyanohydrins. Due to their convergent evolution, finding new representatives is challenging. Here we show the discovery of unique HNL enzymes from the fern Davallia tyermannii by coalescence of transcriptomics, proteomics and enzymatic screening. It is the first protein with a Bet v1-like protein fold exhibiting HNL activity, and has a new catalytic center, as shown by protein crystallography. Biochemical properties of D. tyermannii HNLs open perspectives for the development of a complementary class of biocatalysts for the stereoselective synthesis of cyanohydrins. This work shows that systematic integration of -omics data facilitates discovery of enzymes with unpredictable sequences and helps to extend our knowledge about enzyme diversity.

  18. Phenylalanine ammonia lyase catalyzed synthesis of amino acids by an MIO-cofactor independent pathway.

    Science.gov (United States)

    Lovelock, Sarah L; Lloyd, Richard C; Turner, Nicholas J

    2014-04-25

    Phenylalanine ammonia lyases (PALs) belong to a family of 4-methylideneimidazole-5-one (MIO) cofactor dependent enzymes which are responsible for the conversion of L-phenylalanine into trans-cinnamic acid in eukaryotic and prokaryotic organisms. Under conditions of high ammonia concentration, this deamination reaction is reversible and hence there is considerable interest in the development of PALs as biocatalysts for the enantioselective synthesis of non-natural amino acids. Herein the discovery of a previously unobserved competing MIO-independent reaction pathway, which proceeds in a non-stereoselective manner and results in the generation of both L- and D-phenylalanine derivatives, is described. The mechanism of the MIO-independent pathway is explored through isotopic-labeling studies and mutagenesis of key active-site residues. The results obtained are consistent with amino acid deamination occurring by a stepwise E1 cB elimination mechanism.

  19. Synthesis of d- and l-Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process**

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L; Weise, Nicholas J; Ahmed, Syed T; Turner, Nicholas J

    2015-01-01

    The synthesis of substituted d-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural d-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the d-configured product. Furthermore, the system was extended to the preparation of those l-phenylalanines which are obtained with a low ee value using PAL amination. PMID:25728350

  20. Synthesis of d‐ and l‐Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process†

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L.; Weise, Nicholas J.; Ahmed, Syed T.

    2015-01-01

    Abstract The synthesis of substituted d‐phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one‐pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high‐throughput solid‐phase screening method has also been developed to identify PALs with higher rates of formation of non‐natural d‐phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the d‐configured product. Furthermore, the system was extended to the preparation of those l‐phenylalanines which are obtained with a low ee value using PAL amination. PMID:27478261

  1. Synthesis of d- and l-Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process.

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L; Weise, Nicholas J; Ahmed, Syed T; Turner, Nicholas J

    2015-04-07

    The synthesis of substituted d-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural d-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the d-configured product. Furthermore, the system was extended to the preparation of those l-phenylalanines which are obtained with a low ee value using PAL amination.

  2. Suvanine Sesterterpenes from a Tropical Sponge Coscinoderma sp. Inhibit Isocitrate Lyase in the Glyoxylate Cycle

    Directory of Open Access Journals (Sweden)

    So-Hyoung Lee

    2014-10-01

    Full Text Available The glyoxylate cycle is a sequence of anaplerotic reactions catalyzed by the key enzymes isocitrate lyase (ICL and malate synthase (MLS. Mutants of Candida albicans lacking ICL are markedly less virulent in mice than the wild-type. Suvanine sesterterpenes (1−9 isolated from a tropical sponge Coscinoderma sp. were evaluated for their inhibitory activities toward recombinant ICL from C. albicans. These studies led to the identification of a potent ICL inhibitor, suvanine salt (2, which possesses a sodium counterion and displays an inhibitory concentration value (IC50 of 6.35 μM. The growth phenotype of ICL deletion mutants and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR analyses indicated that compound 2 inhibits the ICL mRNA expression in C. albicans under C2-carbon-utilizing conditions. The present data highlight the potential for suvanine sesterterpenes treatment of C. albicans infections via inhibition of ICL activity.

  3. Synthesis of D- and L-phenylalanine derivatives by phenylalanine ammonia lyases: a multienzymatic cascade process.

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L; Weise, Nicholas J; Ahmed, Syed T; Turner, Nicholas J

    2015-04-01

    The synthesis of substituted D-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural D-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the D-configured product. Furthermore, the system was extended to the preparation of those L-phenylalanines which are obtained with a low ee value using PAL amination.

  4. Preparation of bioimprinting cross-linked enzyme aggregates of phenylalanine ammonia lyase and it's partial properties

    Directory of Open Access Journals (Sweden)

    Jiandong CUI

    2015-12-01

    Full Text Available Phenylalanine ammonia lyase (PAL is a key enzyme for production of L-phenylalanine. Currently, PAL is mainly obtained from Rhodotorula PAL However, Rhodotorula PAL exhibits poor stability, which limits its industrial application. In this study, bioimprinting cross-linked enzyme aggregates of PAL (PAL-iCLEAs is developed by combining cross-linked enzyme aggregates technology and imprinted enzyme method. The most optimal imprinting molecule substrate is screened. Moreover, some characteristics of the PAL-iCLEAs are examined. The results show that the most suitable substrates for preparing PAL-iCLEAs is tran-cinnamic acid. The optimal temperature and pH was 50 ℃ and 10.5, respectively. In addition, PAL-iCLEAs shows good reusability, the recovery of PAL activity still remained 32% after reusing 9 times.

  5. Relationship between cystathionine γ-lyase gene polymorphism and essential hypertension in Northern Chinese Han population

    Institute of Scientific and Technical Information of China (English)

    LI Yun; ZHAO Qi; LIU Xiao-li; WANG Lai-yuan; LU Xiang-feng; LI Hong-fang; CHEN Shu-feng; HUANG Jian-feng; GU Dong-feng

    2008-01-01

    Background Hydrogen sulfide(H2S)plays an important role in the smooth muscle cell relaxation and thereby participates in the development of hypertension. Cystathionine γ-lyase is the key enzyme in the endogenous production of H2S. Up to now, the reports on the relationship between the polymorphisms of cystathionine γ-lyase gene (CTH) and essential hypertension(EH)are limited. This study was designed to assess their underlying relationship. Methods A total of 503 hypertensive patients and 490 age-, gender-and area-matched normotensive controls were enrolled in this study. Based on the FASTSNP, a web server to identify putative functional single nucleotide polymorphisms (SNPs) of genes, we selected two SNPs, rs482843 and rs1021737, in the CTH gene for genotyping. Genotyping was performed by the polymerase chain reaction and restriction fragment length polymorphism method (PCR-RFLP). The frequencies of the alleles and genotypes between cases and controls were compared by the chi-square test. The program Haplo. stats was used to investigate the relationship between the haplotypes and EH. Results These two SNPs were in Hardy-Weinberg Equilibrium in both cases and controls. The genotype distribution and allele frequencies of them did not significantly differ between cases and controls(all P>0.05). In the stepwise logistic regression analysis we failed to observe their association with hypertension. In addition, none of the four estimated haplotypes or diplotypes significantly increased or decreased the risk of hypertension before or after adjustment for several known risk factors. Conclusions The present study suggests that the SNPs rs482843 and rs1021737 of the CTH gene were not associated with essential hypertension in the Northern Chinese Han population. However, replications in other populations and further functional studies are still necessary to clarify the role of the CTH gene in the pathogenesis of EH.

  6. A C⋅As lyase for degradation of environmental organoarsenical herbicides and animal husbandry growth promoters

    Science.gov (United States)

    Yoshinaga, Masafumi; Rosen, Barry P.

    2014-01-01

    Arsenic is the most widespread environmental toxin. Substantial amounts of pentavalent organoarsenicals have been used as herbicides, such as monosodium methylarsonic acid (MSMA), and as growth enhancers for animal husbandry, such as roxarsone (4-hydroxy-3-nitrophenylarsonic acid) [Rox(V)]. These undergo environmental degradation to more toxic inorganic arsenite [As(III)]. We previously demonstrated a two-step pathway of degradation of MSMA to As(III) by microbial communities involving sequential reduction to methylarsonous acid [MAs(III)] by one bacterial species and demethylation from MAs(III) to As(III) by another. In this study, the gene responsible for MAs(III) demethylation was identified from an environmental MAs(III)-demethylating isolate, Bacillus sp. MD1. This gene, termed arsenic inducible gene (arsI), is in an arsenic resistance (ars) operon and encodes a nonheme iron-dependent dioxygenase with C⋅As lyase activity. Heterologous expression of ArsI conferred MAs(III)-demethylating activity and MAs(III) resistance to an arsenic-hypersensitive strain of Escherichia coli, demonstrating that MAs(III) demethylation is a detoxification process. Purified ArsI catalyzes Fe2+-dependent MAs(III) demethylation. In addition, ArsI cleaves the C⋅As bond in trivalent roxarsone and other aromatic arsenicals. ArsI homologs are widely distributed in prokaryotes, and we propose that ArsI-catalyzed organoarsenical degradation has a significant impact on the arsenic biogeocycle. To our knowledge, this is the first report of a molecular mechanism for organoarsenic degradation by a C⋅As lyase. PMID:24821808

  7. A C⋅As lyase for degradation of environmental organoarsenical herbicides and animal husbandry growth promoters.

    Science.gov (United States)

    Yoshinaga, Masafumi; Rosen, Barry P

    2014-05-27

    Arsenic is the most widespread environmental toxin. Substantial amounts of pentavalent organoarsenicals have been used as herbicides, such as monosodium methylarsonic acid (MSMA), and as growth enhancers for animal husbandry, such as roxarsone (4-hydroxy-3-nitrophenylarsonic acid) [Rox(V)]. These undergo environmental degradation to more toxic inorganic arsenite [As(III)]. We previously demonstrated a two-step pathway of degradation of MSMA to As(III) by microbial communities involving sequential reduction to methylarsonous acid [MAs(III)] by one bacterial species and demethylation from MAs(III) to As(III) by another. In this study, the gene responsible for MAs(III) demethylation was identified from an environmental MAs(III)-demethylating isolate, Bacillus sp. MD1. This gene, termed arsenic inducible gene (arsI), is in an arsenic resistance (ars) operon and encodes a nonheme iron-dependent dioxygenase with C ⋅ As lyase activity. Heterologous expression of ArsI conferred MAs(III)-demethylating activity and MAs(III) resistance to an arsenic-hypersensitive strain of Escherichia coli, demonstrating that MAs(III) demethylation is a detoxification process. Purified ArsI catalyzes Fe(2+)-dependent MAs(III) demethylation. In addition, ArsI cleaves the C ⋅ As bond in trivalent roxarsone and other aromatic arsenicals. ArsI homologs are widely distributed in prokaryotes, and we propose that ArsI-catalyzed organoarsenical degradation has a significant impact on the arsenic biogeocycle. To our knowledge, this is the first report of a molecular mechanism for organoarsenic degradation by a C ⋅ As lyase.

  8. An active site homology model of phenylalanine ammonia-lyase from Petroselinum crispum.

    Science.gov (United States)

    Röther, Dagmar; Poppe, László; Morlock, Gaby; Viergutz, Sandra; Rétey, János

    2002-06-01

    The plant enzyme phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) shows homology to histidine ammonia-lyase (HAL) whose structure has been solved by X-ray crystallography. Based on amino-acid sequence alignment of the two enzymes, mutagenesis was performed on amino-acid residues that were identical or similar to the active site residues in HAL to gain insight into the importance of this residues in PAL for substrate binding or catalysis. We mutated the following amino-acid residues: S203, R354, Y110, Y351, N260, Q348, F400, Q488 and L138. Determination of the kinetic constants of the overexpressed and purified enzymes revealed that mutagenesis led in each case to diminished activity. Mutants S203A, R354A and Y351F showed a decrease in kcat by factors of 435, 130 and 235, respectively. Mutants F400A, Q488A and L138H showed a 345-, 615- and 14-fold lower kcat, respectively. The greatest loss of activity occurred in the PAL mutants N260A, Q348A and Y110F, which were 2700, 2370 and 75 000 times less active than wild-type PAL. To elucidate the possible function of the mutated amino-acid residues in PAL we built a homology model of PAL based on structural data of HAL and mutagenesis experiments with PAL. The homology model of PAL showed that the active site of PAL resembles the active site of HAL. This allowed us to propose possible roles for the corresponding residues in PAL catalysis.

  9. 基于 EZproxy 日志的电子资源异常访问行为研究%Research on Abnormal Access to Electronic Resources Based on EZproxy Logs

    Institute of Scientific and Technical Information of China (English)

    雷东升; 郭振英

    2016-01-01

    The off - campus access to electronic resources in the library benefits readers a lot .Meanwhile ,some abnormal access behavior arises .The paper analyzed the electronic resources access log with EZproxyog proxy server ,designed and devel-oped the EZproxy log analysis system so as to pretreat ,upload ,count and analyze the access log to electronic resources .To dis-cover the abnormal access behavior of readers on the basis of the characteristics of their access and to classify the abnormal behav -ior , the paper could avoid that IP is temporarily blocked by the supporters of database of electronic resources in the library so that can maintain the readers' rights and improve the efficiency of resource access .%校外访问图书馆电子资源在方便读者的同时也出现一些异常访问行为,利用 EZproxy 代理服务器日志信息分析异常访问行为特征,设计并开发 EZproxy 日志分析系统,完成对电子资源访问日志的预处理、上传、统计和分析,从访问特征发掘读者的异常访问行为,对异常行为情况分类处理,基本避免了异常访问行为导致图书馆电子资源被数据库商临时封掉 IP 的现象出现,维护图书馆读者的合法权利,提高资源访问效率。

  10. INFLUENCE OF COBALT IONS ON ENZYME ACTIVTY OF ISOCITRIATE LYASE AND ITS REGULATION IN CONDITION OF SEED GERMINATION OF GLYCINE MAX L

    National Research Council Canada - National Science Library

    Chechui O. F

    2012-01-01

    We investigated the activity of isocitrate lyase in seeds of Glycine max L. after 24, 72, and 120 hours of germination and effect of cobalt ions on the activity of the enzyme in time limit of the experiment...

  11. Family 13 carbohydrate-binding module of alginate lyase from Agarivorans sp. L11 enhances its catalytic efficiency and thermostability, and alters its substrate preference and product distribution.

    Science.gov (United States)

    Li, Shangyong; Yang, Xuemei; Bao, Mengmeng; Wu, Ying; Yu, Wengong; Han, Feng

    2015-05-01

    The carbohydrate-binding module (CBM) in polysaccharide hydrolases plays a key role in the hydrolysis of cellulose, xylan and chitin. However, the function of CBM in alginate lyases has not been elucidated. A new alginate lyase gene, alyL2, was cloned from the marine bacterium Agarivorans sp. L11 by using degenerate and site-finding PCR. The alginate lyase, AlyL2, contained an N-terminal CBM13 and a C-terminal catalytic family 7 polysaccharide lyase (PL7) module. To better understand the function of CBM13 in alginate lyase AlyL2, the full-length enzyme (AlyL2-FL) and its catalytic module (AlyL2-CM) were expressed in Escherichia coli and characterized. The specific activity and catalytic efficiency of AlyL2-FL were approximately twice those of AlyL2-CM. The half-lives of AlyL2-FL were 4.7-6.6 times those of AlyL2-CM at 30-50°C. In addition, the presence of CBM13 in AlyL2 changed its substrate preference and increased the percentage of disaccharides from 50.5% to 64.6% in the total products. This first report of the function of CBM13 in alginate lyase provides new insights into the degradation of alginate by marine microorganisms.

  12. Identification, expression, and characterization of a novel bacterial RGI Lyase enzyme for the production of bio-functional fibers

    DEFF Research Database (Denmark)

    da Silva, Ines Isabel Cardoso Rodrigues; Larsen, Dorte Møller; Meyer, Anne S.

    2011-01-01

    molecular weight of the mature RGI Lyase of 596 amino acids. By use of a statistical design approach, with potato rhamnogalacturonan as the substrate, the optimal reaction conditions for the RGI Lyase were established to be: 61°C, pH 8.1, and 2mM of both Ca2+ and Mn2+ (specific activity 18.4U/mg; KM 1.2mg....../ml). The addition of both Ca2+ and Mn2+ was essential for enzyme activity. The enzyme retained its catalytic activity at higher temperatures and the enzyme has a half life at 61°C of 15min. The work thus demonstrated the workability of in silico based screening coupled with a synthetic biology approach for gene...

  13. Analysis on the Thinking Modes of Medical Users Utilizing Library Electronic Resources%医药学用户使用图书馆电子资源的思维模式分析

    Institute of Scientific and Technical Information of China (English)

    陈东滨; 应峻; 辛继宾; 徐一新

    2012-01-01

    The paper studies the thinking modes of medical users utilizing electronic resources in college and university libraries. Combining with the questionnaires,in - depth analysis of utilization desire,utilization decision,impact factors of utilization behaviors are compiled,in order to provide references for college and university libraries formulating electronic resources marketing strategies.%研究高校图书馆医药学用户在使用电子资源过程中的思维模式,结合问卷调查结果深入分析思维模式中使用意愿、使用决策、使用行为的影响因素,为高校图书馆制定电子资源营销策略提供依据。

  14. Analysis of the sulfur-regulated control of the cystathionine γ-lyase gene of Neurospora crassa

    Directory of Open Access Journals (Sweden)

    Reveal Brad S

    2012-07-01

    Full Text Available Abstract Background Cystathionine γ-lyase plays a key role in the transsulfuration pathway through its primary reaction of catalyzing the formation of cysteine from cystathionine. The Neurospora crassa cystathionine γ-lyase gene (cys-16+ is of particular interest in dissecting the regulation and dynamics of transsulfuration. The aim of this study was to determine the regulatory connection of cys-16+ to the Neurospora sulfur regulatory network. In addition, the cys-16+ promoter was characterized with the goal of developing a strongly expressed and regulatable gene expression tool. Findings The cystathionine γ-lyase cys-16+ gene was cloned and characterized. The gene, which contains no introns, encodes a protein of 417 amino acids with conserved pyridoxal 5’-phosphate binding site and substrate-cofactor binding pocket. Northern blot analysis using wild type cells showed that cys-16+ transcript levels increased under sulfur limiting (derepressing conditions and were present only at a low level under sulfur sufficient (repressing conditions. In contrast, cys-16+ transcript levels in a Δcys-3 regulatory mutant were present at a low level under either derepressing or repressing conditions. Gel mobility shift analysis demonstrated the presence of four CYS3 transcriptional activator binding sites on the cys-16+ promoter, which were close matches to the CYS3 consensus binding sequence. Conclusions In this work, we confirm the control of cystathionine γ-lyase gene expression by the CYS3 transcriptional activator through the loss of cys-16+ expression in a Δcys-3 mutant and through the in vitro binding of CYS3 to the cys-16+ promoter at four sites. The highly regulated cys-16+ promoter should be a useful tool for gene expression studies in Neurospora

  15. Sunlight-stimulated phenylalanine ammonia-lyase (PAL) activity and anthocyanin accumulation in exocarp of ‘Mahajanaka’ mango

    OpenAIRE

    Kobkiat Saengnil

    2011-01-01

    The activity of phenylalanine ammonia-lyase (PAL) required for anthocyanin synthesis was stimulated by sunlight exposure resulting in the development of red colour in ‘Mahajanaka’ mango exocarp, which occurred only on the sunlight-exposed side of the fruit. The accumulation of anthocyanin was concurrent with the increase in PAL activity in the mature stage of the fruit. The exposed side of the fruit had higher PAL activity, endogenous sugar content, and anthocyanin accumulation than the unexp...

  16. Review of Researches on the Usage Standard Management of Electronic Resources in China from 2000 to 2010%2000—20l0年我国电子资源使用的规范管理研微

    Institute of Scientific and Technical Information of China (English)

    宛玲; 杜坤

    2012-01-01

    In recent years, electronic resources play an increasingly important role in research, teaching and other works. Through the statistical analysis of the domestic research on the usage standard management of electronic resources from 2000 to 2010, we find that the issue of the usage standard management of electronic resources is increasingly concerned by the public and researchers. But there are still some problems, such as lack of systematic discussion and empirical research, scattered research topics, most research results on guidance proposals, and so on. Our researches about usage standard management of electronic resources should strengthen researches on the user, related technologies, licensing alliance, strengthen the communication between libraries and database providers, and strengthen the analysis and absorption of foreign experience.%目前,电子资源在科研、教学等工作中扮演着越来越重要的角色。通过对2000-2010年我国电子资源使用规范管理研究文献的统计分析发现,虽然公众及科研人员对电子资源使用的规范的关注程度越来越高,但是仍存在缺乏系统性的论述和实证性的研究、研究主题过于分散、研究成果多为指导性建议等问题。我国电子资源使用规范管理研究应加强对用户、相关技术、许可联盟的研究,加强对图书馆与数据库商交流的研究,加强对国外经验的分析与吸收。

  17. 高校图书馆电子资源购买过程中的委托-代理关系探究%Principal-agent Relationship During the Electronic Resources Purchase Process of University Libraries

    Institute of Scientific and Technical Information of China (English)

    桂君; 吴冬曼

    2012-01-01

    The prineipal-agent relationship is throughout the whole process of the electronic resources purchase for university libraries. Based on the asymmetric informatiun theory the issues of information asymmetries in the purchase process of electronic resources for university libraries are analyzed. The major prineipal-agent relationships between the university libraries, the group organizers and the database providers ate studied. The operational characteristics and existing problems in the purchase process of electronic resources for university libraries are also discussed. Taking this opportunity to attention the principal-agent relationships existed in the electronic resources purchase of university libraries, the authors hope to solve some problems caused by the market information asymmetry.%委托-代理关系贯穿了高校图书馆电子资源的购买全过程,,基于信息不对称理论,分析高校图书馆电子资源购买中的信息不对称现象,并以高校图书馆、集团组织者、数据库提供者为主体,研究高校图书馆电子资源采购过程中存在的几种主要委托-代理关系、业务特点和存在的问题、通过对委托-代理关系的研究和分析,合理把握电子资源采购的规律,可以部分解决高校电子资源购买中由市场信息不平衡所带来的问题。

  18. NMR determination of lysine pKa values in the Pol lambda lyase domain: mechanistic implications.

    Science.gov (United States)

    Gao, Guanghua; DeRose, Eugene F; Kirby, Thomas W; London, Robert E

    2006-02-14

    The base excision repair (BER) process requires removal of an abasic deoxyribose-5-phosphate group, a catalytic activity that has been demonstrated for the N-terminal 8 kDa domain of DNA polymerase beta (Pol beta), and for the homologous domain of DNA polymerase lambda (Pol lambda). Previous studies have demonstrated that this activity results from formation of a Schiff base adduct of the abasic deoxyribose C-1' with a lysine residue (K312 in the case of Pol lambda), followed by a beta-elimination reaction. To better understand the underlying chemistry, we have determined pKa values for the lysine residues in the Pol lambda lyase domain labeled with [epsilon-13C]lysine. At neutral pH, the H(epsilon) protons on 3 of the 10 lysine residues in this domain, K287, K291, and K312, exhibit chemical shift inequivalence that results from immobilization of the lysyl side chains. For K287 and K291, this results from the K287-E261 and K291-E298 salt bridge interactions, while for K312, immobilization apparently results from steric and hydrogen-bonding interactions that constrain the position of the lysine side chain. The pKa value of K312 is depressed to 9.58, a value indicating that at physiological pH K312 will exist predominantly in the protonated form. Titration of the domain with hairpin DNA containing a 5'-tetrahydrofuran terminus to model the abasic site produced shifts of the labeled lysine resonances that were in fast exchange but appeared to be complete at a stoichiometry of approximately 1:1.3, consistent with a dissociation constant of approximately 1 microM. The epsilon-proton shifts of K273 were the most sensitive to the addition of the DNA, apparently due to changes in the relative orientation between K273 and W274 in the DNA complex. The average pKa values increased by 0.55, consistent with the formation of some DNA-lysine salt bridges and with the general pH increase expected to result from a reduction in the net positive charge of the complex. A general

  19. Inactivation, complementation, and heterologous expression of encP, a novel bacterial phenylalanine ammonia-lyase gene.

    Science.gov (United States)

    Xiang, Longkuan; Moore, Bradley S

    2002-09-06

    The enzyme phenylalanine ammonia-lyase, which catalyzes the nonoxidative deamination of l-phenylalanine to trans-cinnamic acid, is ubiquitously distributed in plants. We now report its characterization for the first time in a bacterium. The phenylalanine ammonia-lyase homologous gene encP from the "Streptomyces maritimus" enterocin biosynthetic gene cluster was functionally characterized and shown to encode the first enzyme in the pathway to the enterocin polyketide synthase starter unit benzoyl-coenzyme A. The disruption of the encP gene completely inhibited the production of cinnamate and enterocin, whereas complementation of the mutant with benzoyl-coenzyme A pathway intermediates or with the wild-type gene encP restored the formation of the benzoate-primed polyketide antibiotic enterocin. Heterologous expression of the encP gene under the control of the ermE* promoter in Streptomyces coelicolor furthermore led to the production of cinnamic acid in the fermented cultures, confirming that the encP gene indeed encodes a novel bacterial phenylalanine ammonia-lyase.

  20. Mechanistic studies of a novel C-S lyase in ergothioneine biosynthesis: the involvement of a sulfenic acid intermediate.

    Science.gov (United States)

    Song, Heng; Hu, Wen; Naowarojna, Nathchar; Her, Ampon Sae; Wang, Shu; Desai, Rushil; Qin, Li; Chen, Xiaoping; Liu, Pinghua

    2015-01-01

    Ergothioneine is a histidine thio-derivative isolated in 1909. In ergothioneine biosynthesis, the combination of a mononuclear non-heme iron enzyme catalyzed oxidative C-S bond formation reaction and a PLP-mediated C-S lyase (EgtE) reaction results in a net sulfur transfer from cysteine to histidine side-chain. This demonstrates a new sulfur transfer strategy in the biosynthesis of sulfur-containing natural products. Due to difficulties associated with the overexpression of Mycobacterium smegmatis EgtE protein, the proposed EgtE functionality remained to be verified biochemically. In this study, we have successfully overexpressed and purified M. smegmatis EgtE enzyme and evaluated its activities under different in vitro conditions: C-S lyase reaction using either thioether or sulfoxide as a substrate in the presence or absence of reductants. Results from our biochemical characterizations support the assignment of sulfoxide 4 as the native EgtE substrate and the involvement of a sulfenic acid intermediate in the ergothioneine C-S lyase reaction.

  1. Molecular and functional analyses of the metC gene of Lactococcus lactis, encoding cystathionine beta-lyase.

    Science.gov (United States)

    Fernández, M; van Doesburg, W; Rutten, G A; Marugg, J D; Alting, A C; van Kranenburg, R; Kuipers, O P

    2000-01-01

    The enzymatic degradation of amino acids in cheese is believed to generate aroma compounds and therefore to be essential for flavor development. Cystathionine beta-lyase (CBL) can convert cystathionine to homocysteine but is also able to catalyze an alpha, gamma elimination. With methionine as a substrate, it produces volatile sulfur compounds which are important for flavor formation in Gouda cheese. The metC gene, which encodes CBL, was cloned from the Lactococcus lactis model strain MG1363 and from strain B78, isolated from a cheese starter culture and known to have a high capacity to produce volatile compounds. The metC gene was found to be cotranscribed with a downstream cysK gene, which encodes a putative cysteine synthase. The MetC proteins of both strains were overproduced in strain MG1363 with the NICE (nisin-controlled expression) system, resulting in a >25-fold increase in cystathionine lyase activity. A disruption of the metC gene was achieved in strain MG1363. Determination of enzymatic activities in the overproducing and knockout strains revealed that MetC is essential for the degradation of cystathionine but that at least one lyase other than CBL contributes to methionine degradation via alpha, gamma elimination to form volatile aroma compounds.

  2. Crystal Structure of PhnH: an Essential Component of Carbon-Phosphorus Lyase in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Adams,M.; Luo, Y.; Hove-Jensen, B.; He, S.; van Staalduinen, L.; Zechel, D.; Jia, Z.

    2008-01-01

    Organophosphonates are reduced forms of phosphorous that are characterized by the presence of a stable carbon-phosphorus (C-P) bond, which resists chemical hydrolysis, thermal decomposition, and photolysis. The chemically inert nature of the C-P bond has raised environmental concerns as toxic phosphonates accumulate in a number of ecosystems. Carbon-phosphorous lyase (CP lyase) is a multienzyme pathway encoded by the phn operon in gram-negative bacteria. In Escherichia coli 14 cistrons comprise the operon (phnCDEFGHIJKLMNOP) and collectively allow the internalization and degradation of phosphonates. Here we report the X-ray crystal structure of the PhnH component at 1.77 Angstroms resolution. The protein exhibits a novel fold, although local similarities with the pyridoxal 5'-phosphate-dependent transferase family of proteins are apparent. PhnH forms a dimer in solution and in the crystal structure, the interface of which is implicated in creating a potential ligand binding pocket. Our studies further suggest that PhnH may be capable of binding negatively charged cyclic compounds through interaction with strictly conserved residues. Finally, we show that PhnH is essential for C-P bond cleavage in the CP lyase pathway.

  3. Structural and catalytic properties of the four phenylalanine ammonia-lyase isoenzymes from parsley (Petroselinum crispum Nym.).

    Science.gov (United States)

    Appert, C; Logemann, E; Hahlbrock, K; Schmid, J; Amrhein, N

    1994-10-01

    Near-full-length cDNAs for the four phenylalanine ammonia-lyase (PAL) isoenzymes in parsley (Petroselium crispum Nym.) were cloned and the complete amino acid sequences deduced. Fusion proteins with glutathione S-transferase were expressed in Escherichia coli, purified and cleaved. All of the resulting phenylalanine ammonia-lyase proteins, as well as the fusion proteins, were catalytically active. The turnover number of one selected isoenzyme, PAL-1, was estimated to be around 22 s-1 for each active site. In contrast to a certain degree of differential expression in various parts of parsley plants, the four phenylalanine ammonia-lyase isoenzymes exhibited very similar apparent Km values for L-phenylalanine (15-24.5 microM) as well as identical temperature (58 degrees C) and pH (8.5) optima. All of them were competitively inhibited by (E)-cinnamate with similar efficiency (Ki values: 9.1-21.5 microM), lacked cooperative behaviour, and accepted L-tyrosine as a substrate with low affinity (Km values: 2.6-7.8 mM). These results suggest that the occurrence of multiple gene copies has a function other than encoding isoenzymes with different enzyme kinetic properties.

  4. Printed Resources and Electronic Resources Integrated Services in Small and Medium-sized Libraries%中小型图书馆印本资源与电子资源一体化服务实践

    Institute of Scientific and Technical Information of China (English)

    刘胜

    2014-01-01

    Through analyzing the integrated service system of library resources, this paper sums up three methods for the integration of printed resources and digital resources including the digital resources catalog, digital resources navigate and open link system, and suggests that the libraries should give priority to books and periodicals integrated retrieval in the integrated service, and carry out the system construction within their capabilities by adopting the methods of making second development, introducing new system, and conducting independent development, etc.%通过对图书馆馆藏一体化服务系统的分析,归纳总结出印本资源与电子资源整合的3种主要模式———电子资源编目、电子资源导航与开放链接,并建议图书馆在进行一体化服务时,优先考虑图书和期刊的整合检索,在系统建设上量力而行,采取二次开发、引进新系统、自主开发等方式。

  5. 基于使用数据的馆藏电子资源评价方法与系统分析%Methods and Systems of Library Electronic Resources Evaluation Analysis Based on Usage Data

    Institute of Scientific and Technical Information of China (English)

    王丹丹

    2014-01-01

    The origin and methods of library electronic resources evaluation were summarized;the statistical standards of library users' us-age data were reviewed. Then four library electronic resources evaluation systems based on library users' usage data which are ScholarlyS-tats,Journal Use Reports,360 Counter and Ustat were compared and contrasted. The related work which librarians need to do and the con-sidering factors about the selection of electronic resources evaluation system was also analyzed.%总结了图书馆馆藏电子资源评价的缘起与方法,梳理了图书馆用户使用数据的统计规范。以此为基础对比了四个基于使用数据的馆藏电子资源评价系统---ScholarlyStats,Journal Use Reports,360 Counter,UStat,分析了图书馆选择电子资源评价系统的考虑因素和需要预先做好的相关工作。

  6. Cloning and characterization of a pectin lyase gene from Colletotrichum lindemuthianum and comparative phylogenetic/structural analyses with genes from phytopathogenic and saprophytic/opportunistic microorganisms.

    Science.gov (United States)

    Lara-Márquez, Alicia; Zavala-Páramo, María G; López-Romero, Everardo; Calderón-Cortés, Nancy; López-Gómez, Rodolfo; Conejo-Saucedo, Ulises; Cano-Camacho, Horacio

    2011-12-09

    Microorganisms produce cell-wall-degrading enzymes as part of their strategies for plant invasion/nutrition. Among these, pectin lyases (PNLs) catalyze the depolymerization of esterified pectin by a β-elimination mechanism. PNLs are grouped together with pectate lyases (PL) in Family 1 of the polysaccharide lyases, as they share a conserved structure in a parallel β-helix. The best-characterized fungal pectin lyases are obtained from saprophytic/opportunistic fungi in the genera Aspergillus and Penicillium and from some pathogens such as Colletotrichum gloeosporioides.The organism used in the present study, Colletotrichum lindemuthianum, is a phytopathogenic fungus that can be subdivided into different physiological races with different capacities to infect its host, Phaseolus vulgaris. These include the non-pathogenic and pathogenic strains known as races 0 and 1472, respectively. Here we report the isolation and sequence analysis of the Clpnl2 gene, which encodes the pectin lyase 2 of C. lindemuthianum, and its expression in pathogenic and non-pathogenic races of C. lindemuthianum grown on different carbon sources. In addition, we performed a phylogenetic analysis of the deduced amino acid sequence of Clpnl2 based on reported sequences of PNLs from other sources and compared the three-dimensional structure of Clpnl2, as predicted by homology modeling, with those of other organisms. Both analyses revealed an early separation of bacterial pectin lyases from those found in fungi and oomycetes. Furthermore, two groups could be distinguished among the enzymes from fungi and oomycetes: one comprising enzymes from mostly saprophytic/opportunistic fungi and the other formed mainly by enzymes from pathogenic fungi and oomycetes. Clpnl2 was found in the latter group and was grouped together with the pectin lyase from C. gloeosporioides. The Clpnl2 gene of C. lindemuthianum shares the characteristic elements of genes coding for pectin lyases. A time-course analysis

  7. Cloning and characterization of a pectin lyase gene from Colletotrichum lindemuthianum and comparative phylogenetic/structural analyses with genes from phytopathogenic and saprophytic/opportunistic microorganisms

    Directory of Open Access Journals (Sweden)

    Lara-Márquez Alicia

    2011-12-01

    Full Text Available Abstract Background Microorganisms produce cell-wall-degrading enzymes as part of their strategies for plant invasion/nutrition. Among these, pectin lyases (PNLs catalyze the depolymerization of esterified pectin by a β-elimination mechanism. PNLs are grouped together with pectate lyases (PL in Family 1 of the polysaccharide lyases, as they share a conserved structure in a parallel β-helix. The best-characterized fungal pectin lyases are obtained from saprophytic/opportunistic fungi in the genera Aspergillus and Penicillium and from some pathogens such as Colletotrichum gloeosporioides. The organism used in the present study, Colletotrichum lindemuthianum, is a phytopathogenic fungus that can be subdivided into different physiological races with different capacities to infect its host, Phaseolus vulgaris. These include the non-pathogenic and pathogenic strains known as races 0 and 1472, respectively. Results Here we report the isolation and sequence analysis of the Clpnl2 gene, which encodes the pectin lyase 2 of C. lindemuthianum, and its expression in pathogenic and non-pathogenic races of C. lindemuthianum grown on different carbon sources. In addition, we performed a phylogenetic analysis of the deduced amino acid sequence of Clpnl2 based on reported sequences of PNLs from other sources and compared the three-dimensional structure of Clpnl2, as predicted by homology modeling, with those of other organisms. Both analyses revealed an early separation of bacterial pectin lyases from those found in fungi and oomycetes. Furthermore, two groups could be distinguished among the enzymes from fungi and oomycetes: one comprising enzymes from mostly saprophytic/opportunistic fungi and the other formed mainly by enzymes from pathogenic fungi and oomycetes. Clpnl2 was found in the latter group and was grouped together with the pectin lyase from C. gloeosporioides. Conclusions The Clpnl2 gene of C. lindemuthianum shares the characteristic elements of

  8. Analysis on Current Situation and Countermeasure of Domestic Electronic Commerce Logistics in the Internet Age——Based on Resource Dependence Theory

    Directory of Open Access Journals (Sweden)

    Zhang Jiapeng

    2017-01-01

    Full Text Available This paper analyzes the status of electric business logistics in the current Internet era in China, and combines the SWOT analysis with AHP to do the empirical analysis, then puts forward the countermeasure that the electric business logistics resource should be shared based on the resource dependence theory. Through the empirical analysis, it is found that the disadvantages and opportunities of the logistics status are important in the Internet era.The resource sharing strategy based on the resource dependence theory is more scientific. The rational use of Internet technology in electric business logistics industry can achieve “sharing”. It is of great significance for its balanced development, intelligent development and optimization and development.

  9. ATP-Citrate Lyase Controls a Glucose-to-Acetate Metabolic Switch

    Directory of Open Access Journals (Sweden)

    Steven Zhao

    2016-10-01

    Full Text Available Mechanisms of metabolic flexibility enable cells to survive under stressful conditions and can thwart therapeutic responses. Acetyl-coenzyme A (CoA plays central roles in energy production, lipid metabolism, and epigenomic modifications. Here, we show that, upon genetic deletion of Acly, the gene coding for ATP-citrate lyase (ACLY, cells remain viable and proliferate, although at an impaired rate. In the absence of ACLY, cells upregulate ACSS2 and utilize exogenous acetate to provide acetyl-CoA for de novo lipogenesis (DNL and histone acetylation. A physiological level of acetate is sufficient for cell viability and abundant acetyl-CoA production, although histone acetylation levels remain low in ACLY-deficient cells unless supplemented with high levels of acetate. ACLY-deficient adipocytes accumulate lipid in vivo, exhibit increased acetyl-CoA and malonyl-CoA production from acetate, and display some differences in fatty acid content and synthesis. Together, these data indicate that engagement of acetate metabolism is a crucial, although partial, mechanism of compensation for ACLY deficiency.

  10. Multiple tandem duplication of the phenylalanine ammonia-lyase genes in Cucumis sativus L.

    Science.gov (United States)

    Shang, Qing-Mao; Li, Liang; Dong, Chun-Juan

    2012-10-01

    Phenylalanine ammonia-lyase (PAL) is the first entry enzyme of the phenylpropanoid pathway, and therefore plays a key role in both plant development and stress defense. In many plants, PAL is encoded by a multi-gene family, and each member is differentially regulated in response to environmental stimuli. In the present study, we report that PAL in cucumber (Cucumis sativus L.) is encoded for by a family of seven genes (designated as CsPAL1-7). All seven CsPALs are arranged in tandem in two duplication blocks, which are located on chromosomes 4 and 6, respectively. The cDNA and protein sequences of the CsPALs share an overall high identity to each other. Homology modeling reveals similarities in their protein structures, besides several slight differences, implying the different activities in conversion of phenylalanine. Phylogenic analysis places CsPAL1-7 in a separate cluster rather than clustering with other plant PALs. Analyses of expression profiles in different cucumber tissues or in response to various stress or plant hormone treatments indicate that CsPAL1-7 play redundant, but divergent roles in cucumber development and stress response. This is consistent with our finding that CsPALs possess overlapping but different cis-elements in their promoter regions. Finally, several duplication events are discussed to explain the evolution of the cucumber PAL genes.

  11. Screening Peptide Inhibitors Using Phage Peptide Library with Isocitrate Lyase in Mycobacterium tuberculosis as Target

    Institute of Scientific and Technical Information of China (English)

    YIN Yu-he; NIU Xue; SUN Bo; TENG Guo-sheng; ZHAO Yun-hui; WU Cong-mei

    2011-01-01

    When devoured by macrophages,Mycobacterium tuberculosis remains persistent in macrophages and gains energy through the glyoxylate bypass to maintain its long-term existence in host cells.Therefore it is possible to stop persistent infections by interdicting the glyoxylate bypass in which the isocitrate lyase(ICL) is the key rate-limiting enzyme and a persistence factor.ICL is the target of anti-TB(TB:tubercular) drugs,which could screen ICL out and effectively inhibit the activity of ICL in Mycobacterium tuberculosis,and because of this,anti-TB drugs can be used to kill persistent Mycobacterium tuberculosis.In this study,the ICL gene of the Mycobacterium tuberculosis H37Rv was cloned successfully and recombinant protein with bioactivity was obtained through the enzyme characteristic appraisal.The specific activity of the recombined ICL is 24 μmol·mg-1 -min-1.The recombined ICL protein was used as the target,and phages which can specifically combine to ICL were screened in the phage 7 peptide library.According to the results of the ELISA and DNA sequence detection,eventually three 7-peptide chains were synthesized.Then the peptide chains were reacted with ICL,respectively,to detect their inhibitory effects on ICL.The results show that all the three 7-peptide chains possessed varying inhibitory effects on the activity of ICL.This study provided lead compounds for the research and development of new peptide anti-TB drugs.

  12. Changes in rice allelopathy and rhizosphere microflora by inhibiting rice phenylalanine ammonia-lyase gene expression.

    Science.gov (United States)

    Fang, Changxun; Zhuang, Yuee; Xu, Tiecheng; Li, Yingzhe; Li, Yue; Lin, Wenxiong

    2013-02-01

    Gene expression of phenylalanine ammonia-lyase (PAL) in allelopathic rice PI312777 was inhibited by RNA interference (RNAi). Transgenic rice showed lower levels of PAL gene expression and PAL activity than wild type rice (WT). The concentrations of phenolic compounds were lower in the root tissues and root exudates of transgenic rice than in those of wild type plants. When barndyardgrass (BYG) was used as the receiver plant, the allelopathic potential of transgenic rice was reduced. The sizes of the bacterial and fungal populations in rice rhizospheric soil at the 3-, 5-, and 7-leaf stages were estimated by using quantitative PCR (qPCR), which showed a decrease in both populations at all stages of leaf development analyzed. However, PI312777 had a larger microbial population than transgenic rice. In addition, in T-RFLP studies, 14 different groups of bacteria were detected in WT and only 6 were detected in transgenic rice. This indicates that there was less rhizospheric bacterial diversity associated with transgenic rice than with WT. These findings collectively suggest that PAL functions as a positive regulator of rice allelopathic potential.

  13. Mitochondrial Sulfide Detoxification Requires a Functional Isoform O-Acetylserine(thiol)lyase C in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Consolación (A)lvarez; Irene García; Luis C.Romero; Cecilia Gotor

    2012-01-01

    In non-cyanogenic species,the main source of cyanide derives from ethylene and camalexin biosyntheses.In mitochondria,cyanide is a potent inhibitor of the cytochrome c oxidase and is metabolized bythe β-cyanoalanine synthase CYS-C1,catalyzing the conversion of cysteine and cyanide to hydrogen sulfide and β-cyanoalanine.The hydrogen sulfide released also inhibits the cytochrome c oxidase and needs to be detoxified by the O-acetylserine(thiol)lyase mitochondrial isoform,OAS-C,which catalyzes the incorporation of sulfide to O-acetylserine to produce cysteine,thus generating a cyclic pathway in the mitochondria.The loss of functional OAS-C isoforms causes phenotypic characteristics very similar to the loss of the CYS-C1 enzyme,showing defects in root hair formation.Genetic complementation with the OAS-C gene rescues the impairment of root hair elongation,restoring the wild-type phenotype.The mitochondria compromise their capacity to properly detoxify cyanide and the resulting sulfide because the latter cannot re-assimilate into cysteine in the oas-c null mutant.Consequently,we observe an accumulation of sulfide and cyanide and of the alternative oxidase,which is unable to prevent the production of reactive oxygen species probably due to the accumulation of both toxic molecules.Our results allow us to suggest that the significance of OAS-C is related to its role in the proper sulfide and cyanide detoxification in mitochondria.

  14. Role of the cystathionine γ lyase/hydrogen sulfide pathway in human melanoma progression.

    Science.gov (United States)

    Panza, Elisabetta; De Cicco, Paola; Armogida, Chiara; Scognamiglio, Giosuè; Gigantino, Vincenzo; Botti, Gerardo; Germano, Domenico; Napolitano, Maria; Papapetropoulos, Andreas; Bucci, Mariarosaria; Cirino, Giuseppe; Ianaro, Angela

    2015-01-01

    In humans, two main metabolic enzymes synthesize hydrogen sulfide (H2 S): cystathionine γ lyase (CSE) and cystathionine β synthase (CBS). A third enzyme, 3-mercaptopyruvate sulfurtransferase (3-MST), synthesizes H2 S in the presence of the substrate 3-mercaptopyruvate (3-MP). The immunohistochemistry analysis performed on human melanoma samples demonstrated that CSE expression was highest in primary tumors, decreased in the metastatic lesions and was almost silent in non-lymph node metastases. The primary role played by CSE was confirmed by the finding that the overexpression of CSE induced spontaneous apoptosis of human melanoma cells. The same effect was achieved using different H2 S donors, the most active of which was diallyl trisulfide (DATS). The main pro-apoptotic mechanisms involved were suppression of nuclear factor-κB activity and inhibition of AKT and extracellular signal-regulated kinase pathways. A proof of concept was obtained in vivo using a murine melanoma model. In fact, either l-cysteine, the CSE substrate, or DATS inhibited tumor growth in mice. In conclusion, we have determined that the l-cysteine/CSE/H2 S pathway is involved in melanoma progression.

  15. Characterization of a bifunctional glyoxylate cycle enzyme, malate synthase/isocitrate lyase, of Euglena gracilis.

    Science.gov (United States)

    Nakazawa, Masami; Nishimura, Masaaki; Inoue, Kengo; Ueda, Mitsuhiro; Inui, Hiroshi; Nakano, Yoshihisa; Miyatake, Kazutaka

    2011-01-01

    The glyoxylate cycle is a modified form of the tricarboxylic acid cycle, which enables organisms to synthesize carbohydrates from C2 compounds. In the protozoan Euglena gracilis, the key enzyme activities of the glyoxylate cycle, isocitrate lyase (ICL) and malate synthase (MS), are conferred by a single bifunctional protein named glyoxylate cycle enzyme (Euglena gracilis glyoxylate cycle enzyme [EgGCE]). We analyzed the enzymatic properties of recombinant EgGCE to determine the functions of its different domains. The 62-kDa N-terminal domain of EgGCE was sufficient to provide the MS activity as expected from an analysis of the deduced amino acid sequence. In contrast, expression of the 67-kDa C-terminal domain of EgGCE failed to yield ICL activity even though this domain was structurally similar to ICL family enzymes. Analyses of truncation mutants suggested that the N-terminal residues of EgGCE are critical for both the ICL and MS activities. The ICL activity of EgGCE increased in the presence of micro-molar concentrations of acetyl-coenzyme A (CoA). Acetyl-CoA also increased the activity in a mutant type EgGCE with a mutation at the acetyl-CoA binding site in the MS domain of EgGCE. This suggests that acetyl-CoA regulates the ICL reaction by binding to a site other than the catalytic center of the MS reaction.

  16. Potential Inhibitors for Isocitrate Lyase of Mycobacterium tuberculosis and Non-M. tuberculosis: A Summary

    Directory of Open Access Journals (Sweden)

    Yie-Vern Lee

    2015-01-01

    Full Text Available Isocitrate lyase (ICL is the first enzyme involved in glyoxylate cycle. Many plants and microorganisms are relying on glyoxylate cycle enzymes to survive upon downregulation of tricarboxylic acid cycle (TCA cycle, especially Mycobacterium tuberculosis (MTB. In fact, ICL is a potential drug target for MTB in dormancy. With the urge for new antitubercular drug to overcome tuberculosis treat such as multidrug resistant strain and HIV-coinfection, the pace of drug discovery has to be increased. There are many approaches to discovering potential inhibitor for MTB ICL and we hereby review the updated list of them. The potential inhibitors can be either a natural compound or synthetic compound. Moreover, these compounds are not necessary to be discovered only from MTB ICL, as it can also be discovered by a non-MTB ICL. Our review is categorized into four sections, namely, (a MTB ICL with natural compounds; (b MTB ICL with synthetic compounds; (c non-MTB ICL with natural compounds; and (d non-MTB ICL with synthetic compounds. Each of the approaches is capable of overcoming different challenges of inhibitor discovery. We hope that this paper will benefit the discovery of better inhibitor for ICL.

  17. Molecular Cloning and Characterization of Hydroperoxide Lyase Gene in the Leaves of Tea Plant (Camellia sinensis).

    Science.gov (United States)

    Deng, Wei-Wei; Wu, Yi-Lin; Li, Ye-Yun; Tan, Zhen; Wei, Chao-Ling

    2016-03-02

    Hydroperoxide lyase (HPL, E.C. 4.1.2.) is the major enzyme in the biosynthesis of natural volatile aldehydes and alcohols in plants, however, little was known about HPL in tea plants (Camellia sinensis). A unique cDNA fragment was isolated by suppressive subtractive hybridization (SSH) from a tea plant subjected to herbivory by tea geometrid Ectropis obliqua. This full length cDNA acquired by RACE was 1476 bp and encoded 491 amino acids. DNA and protein BLAST searches showed high homology to HPL sequences from other plants. The His-tag expression vector pET-32a(+)/CsHPL was constructed and transferred into Escherichia coli Rosetta (DE3). The expression product of recombinant CsHPL in E. coli was about 60 kDa. The enzyme activity of CsHPL was 0.20 μmol·min(-1)·mg(-1). Quantitative RT-PCR analysis indicated CsHPL was strongly up-regulated in tea plants after Ectropis obliqua attack, suggesting that it may be an important candidate for defense against insects in tea plants.

  18. Adenylosuccinate lyase (ADSL) and infantile autism: Absence of previously reported point mutation

    Energy Technology Data Exchange (ETDEWEB)

    Fon, E.A.; Sarrazin, J.; Rouleau, G.A. [Montreal General Hospital (Canada)] [and others

    1995-12-18

    Autism is a heterogeneous neuropsychiatric syndrome of unknown etiology. There is evidence that a deficiency in the enzyme adenylosuccinate lyase (ADSL), essential for de novo purine biosynthesis, could be involved in the pathogenesis of certain cases. A point mutation in the ADSL gene, resulting in a predicted serine-to-proline substitution and conferring structural instability to the mutant enzyme, has been reported previously in 3 affected siblings. In order to determine the prevalence of the mutation, we PCR-amplified the exon spanning the site of this mutation from the genomic DNA of patients fulfilling DSM-III-R criteria for autistic disorder. None of the 119 patients tested were found to have this mutation. Furthermore, on preliminary screening using single-strand conformation polymorphism (SSCP), no novel mutations were detected in the coding sequence of four ADSL exons, spanning approximately 50% of the cDNA. In light of these findings, it appears that mutations in the ADSL gene represent a distinctly uncommon cause of autism. 12 refs., 2 figs.

  19. Inhibition of Escherichia coli tryptophan indole-lyase by tryptophan homologues.

    Science.gov (United States)

    Do, Quang T; Nguyen, Giang T; Celis, Victor; Phillips, Robert S

    2014-10-15

    We have designed, synthesized and evaluated homotryptophan analogues as possible mechanism-based inhibitors for Escherichia coli tryptophan indole-lyase (tryptophanase, TIL, E.C. 4.1.99.1). As a quinonoid structure is an intermediate in the reaction mechanism of TIL, we anticipated that homologation of the physiological substrate, L-Trp would provide analogues resembling the transition state for β-elimination, and potentially inhibit TIL. Our results demonstrate that L-homotryptophan (1a) is a moderate competitive inhibitor of TIL, with Ki=67 μM, whereas L-bishomotryptophan (1b) displays more potent inhibition, with Ki=4.7 μM. Pre-steady-state kinetics indicated the formation of an external aldimine and quinonoid with 1a, but only the formation of an external aldimine for 1b, suggesting differences in the inhibition mechanism. These results demonstrate that formation of a quinonoid complex is not required for strong inhibition. In addition, the Trp analogues were evaluated as inhibitors of Salmonella typhimurium Trp synthase. Our results indicate that compound 1b is at least 25-fold more selective toward TIL than Trp synthase. We report that compound 1b is comparable to the most potent inhibitor previously reported, while displaying high selectivity for TIL. Thus, 1b is a potential lead for the development of novel antibacterials.

  20. Sphingosine-1-phosphate lyase mutations cause primary adrenal insufficiency and steroid-resistant nephrotic syndrome

    Science.gov (United States)

    Prasad, Rathi; Hadjidemetriou, Irene; Meimaridou, Eirini; Buonocore, Federica; Saleem, Moin; Hurcombe, Jenny; Bierzynska, Agnieszka; Barbagelata, Eliana; Bergadá, Ignacio; Cassinelli, Hamilton; Das, Urmi; Krone, Ruth; Hacihamdioglu, Bulent; Sari, Erkan; Yesilkaya, Ediz; Storr, Helen L.; Clemente, Maria; Fernandez-Cancio, Monica; Camats, Nuria; Ram, Nanik; Achermann, John C.; Van Veldhoven, Paul P.; Guasti, Leonardo; Braslavsky, Debora; Guran, Tulay; Metherell, Louise A.

    2017-01-01

    Primary adrenal insufficiency is life threatening and can present alone or in combination with other comorbidities. Here, we have described a primary adrenal insufficiency syndrome and steroid-resistant nephrotic syndrome caused by loss-of-function mutations in sphingosine-1-phosphate lyase (SGPL1). SGPL1 executes the final decisive step of the sphingolipid breakdown pathway, mediating the irreversible cleavage of the lipid-signaling molecule sphingosine-1-phosphate (S1P). Mutations in other upstream components of the pathway lead to harmful accumulation of lysosomal sphingolipid species, which are associated with a series of conditions known as the sphingolipidoses. In this work, we have identified 4 different homozygous mutations, c.665G>A (p.R222Q), c.1633_1635delTTC (p.F545del), c.261+1G>A (p.S65Rfs*6), and c.7dupA (p.S3Kfs*11), in 5 families with the condition. In total, 8 patients were investigated, some of whom also manifested other features, including ichthyosis, primary hypothyroidism, neurological symptoms, and cryptorchidism. Sgpl1–/– mice recapitulated the main characteristics of the human disease with abnormal adrenal and renal morphology. Sgpl1–/– mice displayed disrupted adrenocortical zonation and defective expression of steroidogenic enzymes as well as renal histology in keeping with a glomerular phenotype. In summary, we have identified SGPL1 mutations in humans that perhaps represent a distinct multisystemic disorder of sphingolipid metabolism. PMID:28165343

  1. Enzymatic Hydrolysis of Alginate to Produce Oligosaccharides by a New Purified Endo-Type Alginate Lyase

    Science.gov (United States)

    Zhu, Benwei; Chen, Meijuan; Yin, Heng; Du, Yuguang; Ning, Limin

    2016-01-01

    Enzymatic hydrolysis of sodium alginate to produce alginate oligosaccharides has drawn increasing attention due to its advantages of containing a wild reaction condition, excellent gel properties and specific products easy for purification. However, the efficient commercial enzyme tools are rarely available. A new alginate lyase with high activity (24,038 U/mg) has been purified from a newly isolated marine strain, Cellulophaga sp. NJ-1. The enzyme was most active at 50 °C and pH 8.0 and maintained stability at a broad pH range (6.0–10.0) and temperature below 40 °C. It had broad substrate specificity toward sodium alginate, heteropolymeric MG blocks (polyMG), homopolymeric M blocks (polyM) and homopolymeric G blocks (polyG), and possessed higher affinity toward polyG (15.63 mM) as well as polyMG (23.90 mM) than polyM (53.61 mM) and sodium alginate (27.21 mM). The TLC and MS spectroscopy analysis of degradation products suggested that it completely hydrolyzed sodium alginate into oligosaccharides of low degrees of polymerization (DPs). The excellent properties would make it a promising tool for full use of sodium alginate to produce oligosaccharides. PMID:27275826

  2. The variability in DMSP content and DMSP lyase activity in marine dinoflagellates

    Science.gov (United States)

    Caruana, Amandine M. N.; Malin, Gill

    2014-01-01

    More than 20 years ago Maureen Keller and co-workers published a study that identified dinoflagellates as an important marine phytoplankton group with respect to the production of dimethylsulphoniopropionate (DMSP). Here, we present a synthesis and analysis of all the DMSP and DMSP lyase activity (DLA) measurements currently available for dinoflagellates. The data cover 110 species and strains and reveal over 6 orders of magnitude variability in intracellular DMSP concentrations and substantial variations in DLA in 23 strains. Inter-specific variability was explored with reference to a range of biological characteristics. The presence of a theca did not appear to be related to DMSP concentration but there was a potential relationship with toxicity (P = 0.06) and bioluminescent species produced significantly lower concentrations (P marina had no detectable DMSP. The oceanic province of origin significantly affected the DMSP concentrations (P < 0.05) with higher DMSP content observed in dinoflagellates from the Mediterranean province, the Kuroshio Current province and the East Coastal Australian province. Overall this study supports the concept that DMSP-containing dinoflagellates are an important potential source of DMS to the global atmosphere and highlights current gaps in knowledge.

  3. Molecular cloning, characterization and expression of the phenylalanine ammonia-lyase gene from Juglans regia.

    Science.gov (United States)

    Xu, Feng; Deng, Guang; Cheng, Shuiyuan; Zhang, Weiwei; Huang, Xiaohua; Li, Linling; Cheng, Hua; Rong, Xiaofeng; Li, Jinbao

    2012-01-01

    Phenylalanine ammonia-lyase (PAL) is the first key enzyme of the phenypropanoid pathway. A full-length cDNA of PAL gene was isolated from Juglans regia for the first time, and designated as JrPAL. The full-length cDNA of the JrPAL gene contained a 1935bp open reading frame encoding a 645-amino-acid protein with a calculated molecular weight of about 70.4 kD and isoelectric point (pI) of 6.7. The deduced JrPAL protein showed high identities with other plant PALs. Molecular modeling of JrPAL showed that the 3D model of JrPAL was similar to that of PAL protein from Petroselinum crispum (PcPAL), implying that JrPAL may have similar functions with PcPAL. Phylogenetic tree analysis revealed that JrPAL shared the same evolutionary ancestor of other PALs and had a closer relationship with other angiosperm species. Transcription analysis revealed that JrPAL was expressed in all tested tissues including roots, stems, and leaves, with the highest transcription level being found in roots. Expression profiling analyses by real-time PCR revealed that JrPAL expression was induced by a variety of abiotic and biotic stresses, including UV-B, wounding, cold, abscisic acid and salicylic acid.

  4. Characterization of a Functional Role of the Bradyrhizobium japonicum Isocitrate Lyase in Desiccation Tolerance

    Directory of Open Access Journals (Sweden)

    Jeong-Min Jeon

    2015-07-01

    Full Text Available Bradyrhizobium japonicum is a nitrogen-fixing symbiont of soybean. In previous studies, transcriptomic profiling of B. japonicum USDA110, grown under various environmental conditions, revealed the highly induced gene aceA, encoding isocitrate lyase (ICL. The ICL catalyzes the conversion of isocitrate to succinate and glyoxylate in the glyoxylate bypass of the TCA cycle. Here, we evaluated the functional role of B. japonicum ICL under desiccation-induced stress conditions. We purified AceA (molecular mass = 65 kDa from B. japonicum USDA110, using a His-tag and Ni-NTA column approach, and confirmed its ICL enzyme activity. The aceA mutant showed higher sensitivity to desiccation stress (27% relative humidity (RH, compared to the wild type. ICL activity of the wild type strain increased approximately 2.5-fold upon exposure to 27% RH for 24 h. The aceA mutant also showed an increased susceptibility to salt stress. Gene expression analysis of aceA using qRT-PCR revealed a 148-fold induction by desiccation, while other genes involved in the glyoxylate pathway were not differentially expressed in this condition. Transcriptome analyses revealed that stress-related genes, such as chaperones, were upregulated in the wild-type under desiccating conditions, even though fold induction was not dramatic (ca. 1.5–2.5-fold.

  5. The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

    KAUST Repository

    Neumann, Christina

    2014-10-17

    Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6), thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

  6. Production and characterization of a plant alpha-hydroxynitrile lyase in Escherichia coli.

    Science.gov (United States)

    Hughes, J; Lakey, J H; Hughes, M A

    1997-02-01

    The coding sequence of the cyanogenic alpha-hydroxynitrile lyase gene of Manihot esculenta Crantz (cassava) was cloned in the plasmid vector pMal-c2 and expressed in Escherichia coli strain JM105. DNA sequencing showed that the recombinant plasmid contained the same sequence as the cDNA clone pHNL10. Peptide sequencing of the recombinant protein showed that the N-terminus was heterogeneous, with either four or six additional amino acid residues compared with the native protein. Circular dichroism spectra indicated similar secondary structure contents for both proteins. Enzyme assays showed that specific activity of native and recombinant proteins were 0.24 and 0.26 mmol CN(-)/mg/min, respectively; that both proteins had optimal activity at 40 degrees C and pH 5.5; and that both proteins were inhibited by the serine protease inhibitor phenyl-methane sulfonyl flouride (PMSF). Isoelectric focusing of native and recombinant protein revealed multiple isoforms for both proteins; the recombinant protein had a more basic mean isoelectric point (pl) (5.1) than the native protein (4.5).

  7. Design of benzimidazole- and benzoxazole-2-thione derivatives as inhibitors of bacterial hyaluronan lyase.

    Science.gov (United States)

    Braun, Stephan; Botzki, Alexander; Salmen, Sunnhild; Textor, Christian; Bernhardt, Günther; Dove, Stefan; Buschauer, Armin

    2011-09-01

    Bacterial hyaluronan lyases (Hyal) degrade hyaluronan, an important component of the extracellular matrix, and are involved in microbial spread. Hyal inhibitors may serve as tools to study the role of the enzyme, its substrates and products in the course of bacterial infections. Moreover, such enzyme inhibitors are potential candidates for antibacterial combination therapy. Based on crystal structures of Streptococcus pneumoniae Hyal in complex with a hexasaccharide substrate and with different inhibitors, 1-acylated benzimidazole-2-thiones and benzoxazole-2-thiones were derived as new leads for the inhibition of Streptococcus agalactiae strain 4755 Hyal. Structure-based optimization led to N-(3-phenylpropionyl)benzoxazole-2-thione, one of the most potent compounds known to date (IC(50) values: 24 μM at pH 7.4, 15 μM at pH 5). Among the 27 new derivatives, other N-acylated benzimidazoles and benzoxazoles are just as active at pH 7.4, but not at pH 5. The results support a binding mode characterized by interactions with residues in the catalytic site and with a hydrophobic patch.

  8. A high-throughput scintillation proximity assay for sphingosine-1-phosphate lyase.

    Science.gov (United States)

    Kashem, Mohammed A; Wa, Chunling; Wolak, John P; Grafos, Nicholas S; Ryan, Kelli R; Sanville-Ross, Mary L; Fogarty, Kylie E; Rybina, Irina V; Shoultz, Alycia; Molinaro, Teresa; Desai, Sudha N; Rajan, Anusha; Huber, John D; Nelson, Richard M

    2014-06-01

    The emergence of sphingosine-1-phosphate lyase (SPL) as a promising therapeutic target for inflammatory diseases has heightened interest in the identification of small molecules that modulate its activity. The enzymatic activity of SPL is typically measured using radiometric or fluorescence-based assays that require a lipid extraction step, or by direct quantitation of reaction products using mass spectrometry (MS). To facilitate testing large numbers of compounds to identify SPL modulators, we developed a robust scintillation proximity assay (SPA) that is compatible with high-throughput screening (HTS). This assay employs recombinant human full-length SPL in insect cell membrane preparations to catalyze the conversion of biotinylated aminosphingosine-1-[(33)P]phosphate (S1(33)P-biotin) to trans-2-hexadecenal-biotin and ethanolamine [(33)P]phosphate. To validate the SPA and confirm the fidelity of its measurement of SPL enzyme activity, we developed a Rapid-Fire MS method that quantitates nonradiolabeled S1P-biotin. In addition, we developed a simple, scalable method to produce S1(33)P-biotin in quantities sufficient for HTS. The optimized SPA screen in 384-well microplates produced a mean plate-wise Z'-statistic of 0.58 across approximately 3,000 plates and identified several distinct structural classes of SPL inhibitor. Among the inhibitors that the screen identified was one compound with an IC50 of 1.6 μM in the SPA that induced dose-dependent lymphopenia in mice.

  9. Revised domain structure of ulvan lyase and characterization of the first ulvan binding domain

    Science.gov (United States)

    Melcher, Rebecca L. J.; Neumann, Marten; Fuenzalida Werner, Juan Pablo; Gröhn, Franziska; Moerschbacher, Bruno M.

    2017-01-01

    Biomass waste products from green algae have recently been given new life, as these polysaccharides have potential applications in industry, agriculture, and medicine. One such polysaccharide group called ulvans displays many different, potentially useful properties that arise from their structural versatility. Hence, performing structural analyses on ulvan is crucial for future applications. However, chemical reaction–based analysis methods cannot fully characterize ulvan and tend to alter its structure. Thus, better methods require well-characterized ulvan-degrading enzymes. Therefore, we analysed a previously sequenced ulvan lyase (GenebankTM reference number JN104480) and characterized its domains. We suggest that the enzyme consists of a shorter than previously described catalytic domain, a newly identified substrate binding domain, and a C-terminal type 9 secretion system signal peptide. By separately expressing the two domains in E. coli, we confirmed that the binding domain is ulvan specific, having higher affinity for ulvan than most lectins for their ligands (affinity constant: 105 M−1). To our knowledge, this is the first description of an ulvan-binding domain. Overall, identifying this new binding domain is one step towards engineering ulvan enzymes that can be used to characterize ulvan, e.g. through enzymatic/mass spectrometric fingerprinting analyses, and help unlock its full potential. PMID:28327560

  10. Pectin lyase overproduction by Penicillium griseoroseum mutants resistant to catabolite repression.

    Science.gov (United States)

    Lima, Juliana Oliveira; Pereira, Jorge Fernando; Araújo, Elza Fernandes de; Queiroz, Marisa Vieira de

    2017-02-09

    Expression of pectinolytic genes is regulated by catabolic repression limiting the production of pectin lyase (PL) if the natural inducer, pectin, is missing from the growth medium. Here, we report the isolation of Penicillium griseoroseum mutants resistant to 2-deoxy-d-glucose (DG) that show resistance to catabolite repression and overproduce PL. Three spontaneous and nine UV-induced mutants were obtained. Some mutants produced sectors (segments morphologically different) that were also studied. The mutants were analyzed for pectinases production on pectinase-agar plates and five mutants and two sectors showing larger clearing zones than the wild type were selected for quantitative assay. Although PL production higher than the wild type has been found, phenotype instability was observed for most of the mutants and, after transfers to nonselective medium, the DG resistance was no longer present. Only mutants M03 and M04 were stable maintaining the DG-resistance phenotype. When growing for 120h in liquid medium containing glucose with or without pectin, both mutants showed higher PL production. In the presence of glucose as sole carbon source, the mutant M03 produced 7.8-fold more PL than the wild type. Due its phenotypic stability and PL overproduction, the mutant M03 presents potential for industrial applications.

  11. Engineered Citrobacter freundii methionine γ-lyase effectively produces antimicrobial thiosulfinates.

    Science.gov (United States)

    Morozova, Elena A; Kulikova, Vitalia V; Rodionov, Alexei N; Revtovich, Svetlana V; Anufrieva, Natalya V; Demidkina, Tatyana V

    2016-01-01

    Antimicrobial activity of thiosulfinates in situ produced by mixtures of Citrobacter freundii methionine γ-lyase (MGL) with new substrates, l-methionine and S-(alkyl/allyl)-l-cysteine sulfoxides has been recently demonstrated (Anufrieva et al., 2015). This opens a way to the rational design of a new biotechnologically relevant antimicrobial drug producer. To increase the efficiency of the enzyme toward sulfoxides, the mutant forms of MGL, with the replacements of active site cysteine 115 with alanine (C115A MGL) and histidine (C115H MGL) were obtained. The replacement of cysteine 115 by histidine results in the loss of activity of the mutant enzyme in the γ-elimination reaction of physiological substrate, whereas the activity in the β-elimination reaction of characteristic substrates persists. However, the catalytic efficiency of C115H MGL in the β-elimination reaction of S-substituted l-cysteine sulfoxides is increased by about an order of magnitude compared to the wild type MGL. The antibacterial activity of C115H MGL mixtures with a number of sulfoxides was assessed against Gram-positive and Gram-negative bacteria. The bacteriostatic effect was more pronounced against Gram-positive than against Gram-negative bacteria, while antibacterial potential proved to be quite similar. Thus, the mutant enzyme C115H MGL is an effective catalyst, in particular, for decomposition of sulfoxides and the pharmacological couples of the mutant form with sulfoxides might be new antimicrobial agents.

  12. Molecular and Functional Characterization of Sphingosine-1-Phosphate Lyase Homolog from Higher Plants

    Institute of Scientific and Technical Information of China (English)

    Yan Niu; Kunling Chen; Jizhou Wang; Xin Liu; Huanju Qin; Aimin Zhang; Daowen Wang

    2007-01-01

    Sphingosine-1-phosphate lyase (SPL) is involved in degrading the conserved sphingolipid signaling molecule sphingoaine-1-phosphate. However, molecular studies on plant SPL have not been reported to date. Here, we present bloinformatic, molecular and functional analyses of putative SPL proteins from Arabldopsis thaliana and rice (designated as AtSPL and OsSPL, respectively). Amino acid sequence comparison revealed that plant SPL contained the pyridoxal-dependent decarboxylase domain and the conserved residue that may be involved in substrate catalysis. When expressed in Saccharomyces cerevisiae, AtSPL and OsSPL corrected the hypersensitive phenotype of the yeast dpl1 deletion strain, which is deficient in endogenous SPL activity, to exogenous supplied sphingolipid long chain bases (LCBs), suggesting that plant SPL protein is functional in vivo in degrading phosphorylated LCBs. In Arabidopsis, AtSPL transcripts were detected in roots, stems, leaves, flowers and siliques. In pAtSPL-AtSPL::GUS transgenlc lines, the AtSPL::GUS fusion protein was found in a variety of vegetative and reproductive tissues. AtSPL expression level was dynamically regulated during leaf development and senescence, and was steadily and significantly increased in Arabidopsis seedlings treated with the cell death-inducing fungal toxin fumonisin B1. The potential function of SPL in Arabidopsis is discussed.

  13. Mutations underlying 3-Hydroxy-3-Methylglutaryl CoA Lyase deficiency in the Saudi population

    Directory of Open Access Journals (Sweden)

    Rashed Mohammed S

    2006-12-01

    Full Text Available Abstract Background 3-Hydroxy-3-Methylglutaric aciduria (3HMG, McKusick: 246450 is an autosomal recessive branched chain organic aciduria caused by deficiency of the enzyme 3-Hydroxy-3-Methylglutaryl CoA lyase (HL, HMGCL, EC 4.1.3.4. HL is encoded by HMGCL gene and many mutations have been reported. 3HMG is commonly observed in Saudi Arabia. Methods We utilized Whole Genome Amplification (WGA, PCR and direct sequencing to identify mutations underlying 3HMG in the Saudi population. Two patients from two unrelated families and thirty-four 3HMG positive dried blood spots (DBS were included. Results We detected the common missense mutation R41Q in 89% of the tested alleles (64 alleles. 2 alleles carried the frame shift mutation F305fs (-2 and the last two alleles had a novel splice site donor IVS6+1G>A mutation which was confirmed by its absence in more than 100 chromosomes from the normal population. All mutations were present in a homozygous state, reflecting extensive consanguinity. The high frequency of R41Q is consistent with a founder effect. Together the three mutations described account for >94% of the pathogenic mutations underlying 3HMG in Saudi Arabia. Conclusion Our study provides the most extensive genotype analysis on 3HMG patients from Saudi Arabia. Our findings have direct implications on rapid molecular diagnosis, prenatal and pre-implantation diagnosis and population based prevention programs directed towards 3HMG.

  14. Immunolocalization of phenylalanine ammonia-lyase and cinnamate-4-hydroxylase in differentiating xylem of poplar.

    Science.gov (United States)

    Sato, Takahiko; Takabe, Keiji; Fujita, Minoru

    2004-01-01

    Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) and cinnamate-4-hydroxylase (C4H; EC 1.14.13.11) are pivotal enzymes involved in lignification. We synthesized peptides as the epitopes according to the amino acid sequences of these enzymes, coupled them with hemocyanin, and injected them into mice. The antiserums against peptides of PAL and C4H specifically detected PAL and C4H in the crude enzymes extracted from differentiating xylem of poplar, respectively. PAL and C4H were localized in differentiating xylem of poplar. PAL labeling was mainly localized in the cytosol, and somewhat localized on the rough-endoplasmic reticulum (r-ER) and the Golgi apparatus. In contrast, C4H was mainly observed on r-ER and the Golgi apparatus. These findings suggest that conversion of phenylalanine to cinnamic acid occurs in the cytosol and the following reaction occurs near the membrane of r-ER and the Golgi apparatus. The possibility of coordinated localization of PAL and C4H is discussed.

  15. Phenylalanine ammonia-lyase modified with polyethylene glycol: potential therapeutic agent for phenylketonuria.

    Science.gov (United States)

    Ikeda, K; Schiltz, E; Fujii, T; Takahashi, M; Mitsui, K; Kodera, Y; Matsushima, A; Inada, Y; Schulz, G E; Nishimura, H

    2005-11-01

    Phenylketonuria (PKU) is an autosomal recessive genetic disease caused by the defects in the phenylalanine hydroxylase (PAH) gene. Individuals homozygous for defective PAH alleles show elevated levels of systemic phenylalanine and should be under strict dietary control to reduce the risk of neuronal damage associated with high levels of plasma phenylalanine. Researchers predict that plant phenylalanine ammonia-lyase (PAL), which converts phenylalanine to nontoxic t-cinnamic acid, will be an effective therapeutic enzyme for the treatment of PKU. The problems of this potential enzyme therapy have been the low stability in the circulation and the antigenicity of the plant enzyme. Recombinant PAL originated from parsley (Petroselinum crispum) chemically conjugated with activated PEG2 [2,4-bis(O-methoxypolyethyleneglycol)-6-chloro-s-triazine] showed greatly enhanced stability in the circulation and was effective in reducing the plasma concentration of phenylalanine in the circulation of mice. PEG-PAL conjugate will be an effective therapeutic enzyme for the treatment of PKU.

  16. Characterization of a Functional Role of the Bradyrhizobium japonicum Isocitrate Lyase in Desiccation Tolerance.

    Science.gov (United States)

    Jeon, Jeong-Min; Lee, Hae-In; Sadowsky, Michael J; Sugawara, Masayuki; Chang, Woo-Suk

    2015-07-22

    Bradyrhizobium japonicum is a nitrogen-fixing symbiont of soybean. In previous studies, transcriptomic profiling of B. japonicum USDA110, grown under various environmental conditions, revealed the highly induced gene aceA, encoding isocitrate lyase (ICL). The ICL catalyzes the conversion of isocitrate to succinate and glyoxylate in the glyoxylate bypass of the TCA cycle. Here, we evaluated the functional role of B. japonicum ICL under desiccation-induced stress conditions. We purified AceA (molecular mass = 65 kDa) from B. japonicum USDA110, using a His-tag and Ni-NTA column approach, and confirmed its ICL enzyme activity. The aceA mutant showed higher sensitivity to desiccation stress (27% relative humidity (RH)), compared to the wild type. ICL activity of the wild type strain increased approximately 2.5-fold upon exposure to 27% RH for 24 h. The aceA mutant also showed an increased susceptibility to salt stress. Gene expression analysis of aceA using qRT-PCR revealed a 148-fold induction by desiccation, while other genes involved in the glyoxylate pathway were not differentially expressed in this condition. Transcriptome analyses revealed that stress-related genes, such as chaperones, were upregulated in the wild-type under desiccating conditions, even though fold induction was not dramatic (ca. 1.5-2.5-fold).

  17. Molecular cloning and sequence analysis of a phenylalanine ammonia-lyase gene from dendrobium.

    Directory of Open Access Journals (Sweden)

    Qing Jin

    Full Text Available In this study, a phenylalanine ammonia-lyase (PAL gene was cloned from Dendrobium candidum using homology cloning and RACE. The full-length sequence and catalytic active sites that appear in PAL proteins of Arabidopsis thaliana and Nicotiana tabacum are also found: PAL cDNA of D. candidum (designated Dc-PAL1, GenBank No. JQ765748 has 2,458 bps and contains a complete open reading frame (ORF of 2,142 bps, which encodes 713 amino acid residues. The amino acid sequence of DcPAL1 has more than 80% sequence identity with the PAL genes of other plants, as indicated by multiple alignments. The dominant sites and catalytic active sites, which are similar to that showing in PAL proteins of Arabidopsis thaliana and Nicotiana tabacum, are also found in DcPAL1. Phylogenetic tree analysis revealed that DcPAL is more closely related to PALs from orchidaceae plants than to those of other plants. The differential expression patterns of PAL in protocorm-like body, leaf, stem, and root, suggest that the PAL gene performs multiple physiological functions in Dendrobium candidum.

  18. Diagnosis of adenylosuccinate lyase deficiency by metabolomic profiling in plasma reveals a phenotypic spectrum

    Directory of Open Access Journals (Sweden)

    Taraka R. Donti

    2016-09-01

    Full Text Available Adenylosuccinate lyase (ADSL deficiency is a rare autosomal recessive neurometabolic disorder that presents with a broad-spectrum of neurological and physiological symptoms. The ADSL gene produces an enzyme with binary molecular roles in de novo purine synthesis and purine nucleotide recycling. The biochemical phenotype of ADSL deficiency, accumulation of SAICAr and succinyladenosine (S-Ado in biofluids of affected individuals, serves as the traditional target for diagnosis with targeted quantitative urine purine analysis employed as the predominate method of detection. In this study, we report the diagnosis of ADSL deficiency using an alternative method, untargeted metabolomic profiling, an analytical scheme capable of generating semi-quantitative z-score values for over 1000 unique compounds in a single analysis of a specimen. Using this method to analyze plasma, we diagnosed ADSL deficiency in four patients and confirmed these findings with targeted quantitative biochemical analysis and molecular genetic testing. ADSL deficiency is part of a large a group of neurometabolic disorders, with a wide range of severity and sharing a broad differential diagnosis. This phenotypic similarity among these many inborn errors of metabolism (IEMs has classically stood as a hurdle in their initial diagnosis and subsequent treatment. The findings presented here demonstrate the clinical utility of metabolomic profiling in the diagnosis of ADSL deficiency and highlights the potential of this technology in the diagnostic evaluation of individuals with neurologic phenotypes.

  19. Kynurenine aminotransferase III and glutamine transaminase L are identical enzymes that have cysteine S-conjugate β-lyase activity and can transaminate L-selenomethionine.

    Science.gov (United States)

    Pinto, John T; Krasnikov, Boris F; Alcutt, Steven; Jones, Melanie E; Dorai, Thambi; Villar, Maria T; Artigues, Antonio; Li, Jianyong; Cooper, Arthur J L

    2014-11-01

    Three of the four kynurenine aminotransferases (KAT I, II, and IV) that synthesize kynurenic acid, a neuromodulator, are identical to glutamine transaminase K (GTK), α-aminoadipate aminotransferase, and mitochondrial aspartate aminotransferase, respectively. GTK/KAT I and aspartate aminotransferase/KAT IV possess cysteine S-conjugate β-lyase activity. The gene for the former enzyme, GTK/KAT I, is listed in mammalian genome data banks as CCBL1 (cysteine conjugate beta-lyase 1). Also listed, despite the fact that no β-lyase activity has been assigned to the encoded protein in the genome data bank, is a CCBL2 (synonym KAT III). We show that human KAT III/CCBL2 possesses cysteine S-conjugate β-lyase activity, as does mouse KAT II. Thus, depending on the nature of the substrate, all four KATs possess cysteine S-conjugate β-lyase activity. These present studies show that KAT III and glutamine transaminase L are identical enzymes. This report also shows that KAT I, II, and III differ in their ability to transaminate methyl-L-selenocysteine (MSC) and L-selenomethionine (SM) to β-methylselenopyruvate (MSP) and α-ketomethylselenobutyrate, respectively. Previous studies have identified these seleno-α-keto acids as potent histone deacetylase inhibitors. Methylselenol (CH3SeH), also purported to have chemopreventive properties, is the γ-elimination product of SM and the β-elimination product of MSC catalyzed by cystathionine γ-lyase (γ-cystathionase). KAT I, II, and III, in part, can catalyze β-elimination reactions with MSC generating CH3SeH. Thus, the anticancer efficacy of MSC and SM will depend, in part, on the endogenous expression of various KAT enzymes and cystathionine γ-lyase present in target tissue coupled with the ability of cells to synthesize in situ either CH3SeH and/or seleno-keto acid metabolites.

  20. Fiber resources

    Science.gov (United States)

    P. J. Ince

    2004-01-01

    In economics, primary inputs or factors of production define the term ‘resources.’ Resources include land resources (plants, animals, and minerals), labor, capital, and entrepreneurship. Almost all pulp and paper fiber resources are plant materials obtained from trees or agricultural crops. These resources encompass plant materials harvested directly from the land (...

  1. On the development and the utilization of library holding in electronic resources Taking the Library of Shandong University of Science and Technology%试论电子资源的馆藏发展与利用——以山东科技大学图书馆为例

    Institute of Scientific and Technical Information of China (English)

    陈明华; 马圣芹

    2012-01-01

    通过分析电子资源馆藏发展的意义及模式,对电子资源发展的目标及有效管理进行了探讨,并提出一些提高电子资源利用率的措施。%This paper analyses the mode and the importance of library holding development in electronic resources. It also ex- plores the aim and the affective management in electronic resource development and put forwards some measures to improve the utilization ratio of electronic resources.

  2. Electronic Library: A TERI Experiment.

    Science.gov (United States)

    Kar, Debal C.; Deb, Subrata; Kumar, Satish

    2003-01-01

    Discusses the development of Electronic Library at TERI (The Energy and Resources Institute, New Delhi). Highlights include: hardware and software used; the digital library/Virtual Electronic Library; directory of Internet journals; virtual reference resources; electronic collection/Physical Electronic Library; downloaded online full-length…

  3. Innovative Resources for Education and Public Information: Electronic Services, Data and Information from NASA's Hubble Space Telescope and Other NASA Missions.

    Science.gov (United States)

    Christian, Carol A.

    The Space Telescope Science Institute (STScI), which supports the operation of the Hubble Space Telescope, is actively investigating and supporting innovative and experimental methods for improving science and math education content. The educational resources on the World Wide Web are derived from the latest data, scientific results, and advances…

  4. An implementation case study. Implementation of the Indian Health Service's Resource and Patient Management System Electronic Health Record in the ambulatory care setting at the Phoenix Indian Medical Center.

    Science.gov (United States)

    Dunnigan, Anthony; John, Karen; Scott, Andrea; Von Bibra, Lynda; Walling, Jeffrey

    2010-01-01

    The Phoenix Indian Medical Center (PIMC) has successfully implemented the Resource and Patient Management System Electronic Health Record (RPMS-EHR) in its Ambulatory Care departments. One-hundred and twenty-six providers use the system for essentially all elements of documentation, ordering, and coding. Implementation of one function at a time, in one clinical area at a time, allowed for focused training and support. Strong departmental leadership and the development of 'super-users' were key elements. Detailed assessments of each clinic prior to implementation were vital, resulting in optimal workstation utilization and a greater understanding of each clinic's unique flow. Each phase saw an increasing reluctance to revert to old paper processes. The success of this implementation has placed pressure on the remainder of the hospital to implement the RPMS-EHR, and has given the informatics team an increased awareness of what resources are required to achieve this result.

  5. 大學圖書館電子資源之需求分析與行銷策略之研究 A Study of Demands Analysis and Marketing Strategy of Electronic Resources in University Library

    Directory of Open Access Journals (Sweden)

    Huang-Yu Liu

    2008-03-01

    Full Text Available 電子資源的出現,使得知識載體有了新的突破,提高了使用者的便利性與即時性。對於圖書館而言,如何使電子資源的使用效益達到最高,必須思考一套有效的行銷策略。電子資源行銷概念應以讀者為導向,尊重讀者的資訊需求,並利用各種宣傳技巧,行銷電子資源,使圖書館能提供更完善的服務。本研究之目的旨在探討讀者的使用需求及電子資源的推廣策略,以獲致最有效益的行銷方式。研究對象以開南大學日間部四學院(商學院、運輸觀光學院、資訊學院、人文社會學院)學生為樣本,佐以缺口分析模型為分析架構,藉以找出個案中讀者/學生對於電子資源使用的真實需求,並進而歸納出提供服務的大學圖書館在其推廣或行銷服務上可有的因應策略。The emergence of electronic resources has made new breakthrough in knowledge carriers because of their ease of use, instant availability, and the characteristic of no time and space constraints. For public libraries to achieve maximum efficiency in its electronic resources, it is necessary to seek the most effective marketing strategies. Therefore, the marketing concept of the electronic resources should be reader oriented, such as respecting and understanding library user’s information needs. Libraries also need to utilize various media and techniques to market the electronic resources, so that more comprehensive services and experiences can be provided to readers. The purpose of this study is to investigate library user’s needs and promotion strategies of electronic resources in order to identify the most effective ways of marketing. This study focuses on the students of the four colleges (College of Business, College of Tourism, College of Information, and College of Humanities and Social Science in Kainan University as subjects in the survey questionnaire. It uses the Gap Analysis

  6. Arsenic Demethylation by a C·As Lyase in Cyanobacterium Nostoc sp. PCC 7120.

    Science.gov (United States)

    Yan, Yu; Ye, Jun; Xue, Xi-Mei; Zhu, Yong-Guan

    2015-12-15

    Arsenic, a ubiquitous toxic substance, exists mainly as inorganic forms in the environment. It is perceived that organoarsenicals can be demethylated and degraded into inorganic arsenic by microorganisms. Few studies have focused on the mechanism of arsenic demethylation in bacteria. Here, we investigated arsenic demethylation in a typical freshwater cyanobacterium Nostoc sp. PCC 7120. This bacterium was able to demethylate monomethylarsenite [MAs(III)] rapidly to arsenite [As(III)] and also had the ability to demethylate monomethylarsenate [MAs(V)] to As(III). The NsarsI encoding a C·As lyase responsible for MAs(III) demethylation was cloned from Nostoc sp. PCC 7120 and heterologously expressed in an As-hypersensitive strain Escherichia coli AW3110 (ΔarsRBC). Expression of NsarsI was shown to confer MAs(III) resistance through arsenic demethylation. The purified NsArsI was further identified and functionally characterized in vitro. NsArsI existed mainly as the trimeric state, and the kinetic data were well-fit to the Hill equation with K0.5 = 7.55 ± 0.33 μM for MAs(III), Vmax = 0.79 ± 0.02 μM min(-1), and h = 2.7. Both of the NsArsI truncated derivatives lacking the C-terminal 10 residues (ArsI10) or 23 residues (ArsI23) had a reduced ability of MAs(III) demethylation. These results provide new insights for understanding the important role of cyanobacteria in arsenic biogeochemical cycling in the environment.

  7. Genome-wide characterization of phenylalanine ammonia-lyase gene family in watermelon (Citrullus lanatus).

    Science.gov (United States)

    Dong, Chun-Juan; Shang, Qing-Mao

    2013-07-01

    Phenylalanine ammonia-lyase (PAL), the first enzyme in the phenylpropanoid pathway, plays a critical role in plant growth, development, and adaptation. PAL enzymes are encoded by a gene family in plants. Here, we report a genome-wide search for PAL genes in watermelon. A total of 12 PAL genes, designated ClPAL1-12, are identified . Nine are arranged in tandem in two duplication blocks located on chromosomes 4 and 7, and the other three ClPAL genes are distributed as single copies on chromosomes 2, 3, and 8. Both the cDNA and protein sequences of ClPALs share an overall high identity with each other. A phylogenetic analysis places 11 of the ClPALs into a separate cucurbit subclade, whereas ClPAL2, which belongs to neither monocots nor dicots, may serve as an ancestral PAL in plants. In the cucurbit subclade, seven ClPALs form homologous pairs with their counterparts from cucumber. Expression profiling reveals that 11 of the ClPAL genes are expressed and show preferential expression in the stems and male and female flowers. Six of the 12 ClPALs are moderately or strongly expressed in the fruits, particularly in the pulp, suggesting the potential roles of PAL in the development of fruit color and flavor. A promoter motif analysis of the ClPAL genes implies redundant but distinctive cis-regulatory structures for stress responsiveness. Finally, duplication events during the evolution and expansion of the ClPAL gene family are discussed, and the relationships between the ClPAL genes and their cucumber orthologs are estimated.

  8. Phycoerythrin-specific bilin lyase-isomerase controls blue-green chromatic acclimation in marine Synechococcus.

    Science.gov (United States)

    Shukla, Animesh; Biswas, Avijit; Blot, Nicolas; Partensky, Frédéric; Karty, Jonathan A; Hammad, Loubna A; Garczarek, Laurence; Gutu, Andrian; Schluchter, Wendy M; Kehoe, David M

    2012-12-04

    The marine cyanobacterium Synechococcus is the second most abundant phytoplanktonic organism in the world's oceans. The ubiquity of this genus is in large part due to its use of a diverse set of photosynthetic light-harvesting pigments called phycobiliproteins, which allow it to efficiently exploit a wide range of light colors. Here we uncover a pivotal molecular mechanism underpinning a widespread response among marine Synechococcus cells known as "type IV chromatic acclimation" (CA4). During this process, the pigmentation of the two main phycobiliproteins of this organism, phycoerythrins I and II, is reversibly modified to match changes in the ambient light color so as to maximize photon capture for photosynthesis. CA4 involves the replacement of three molecules of the green light-absorbing chromophore phycoerythrobilin with an equivalent number of the blue light-absorbing chromophore phycourobilin when cells are shifted from green to blue light, and the reverse after a shift from blue to green light. We have identified and characterized MpeZ, an enzyme critical for CA4 in marine Synechococcus. MpeZ attaches phycoerythrobilin to cysteine-83 of the α-subunit of phycoerythrin II and isomerizes it to phycourobilin. mpeZ RNA is six times more abundant in blue light, suggesting that its proper regulation is critical for CA4. Furthermore, mpeZ mutants fail to normally acclimate in blue light. These findings provide insights into the molecular mechanisms controlling an ecologically important photosynthetic process and identify a unique class of phycoerythrin lyase/isomerases, which will further expand the already widespread use of phycoerythrin in biotechnology and cell biology applications.

  9. Olive Recombinant Hydroperoxide Lyase, an Efficient Biocatalyst for Synthesis of Green Leaf Volatiles.

    Science.gov (United States)

    Jacopini, Sabrina; Mariani, Magali; de Caraffa, Virginie Brunini-Bronzini; Gambotti, Claude; Vincenti, Sophie; Desjobert, Jean-Marie; Muselli, Alain; Costa, Jean; Berti, Liliane; Maury, Jacques

    2016-06-01

    Volatile C6-aldehydes are the main contributors to the characteristic odor of plants known as "green note" and are widely used by the flavor industry. Biotechnological processes were developed to fulfill the high demand in C6-aldehydes in natural flavorants and odorants. Recombinant hydroperoxide lyases (HPLs) constitute an interesting alternative to overcome drawbacks arising from the use of HPL from plant extracts. Thus, olive recombinant 13-HPL was assayed as biocatalysts to produce C6-aldehydes. Firstly, a cDNA encoding for olive HPL of Leccino variety was isolated and cloned in pQE-30 expression vector. In order to improve the enzyme solubility, its chloroplast transit peptide was deleted. Both enzymes (HPL wild type and HPL deleted) were expressed into Escherichia coli strain M15, purified, characterized, and then used for bioconversion of 13-hydroperoxides of linoleic and linolenic acids. Aldehydes produced were extracted, then identified and quantified using gas chromatography and mass spectrometry. Recombinant HPL wild type (HPLwt) allowed producing 5.61 mM of hexanal and 4.39 mM of 3Z-hexenal, corresponding to high conversion yields of 93.5 and 73 %, respectively. Using HPL deleted (HPLdel) instead of HPLwt failed to obtain greater quantities of hexanal or 3Z-hexenal. No undesirable products were formed, and no isomerization of 3Z-hexenal in 2E-hexenal occurred. The olive recombinant HPLwt appears to be a promising efficient biocatalyst for the production of C6-aldehydes.

  10. Inhibition of Arabidopsis O-acetylserine(thiol)lyase A1 by tyrosine nitration.

    Science.gov (United States)

    Alvarez, Consolación; Lozano-Juste, Jorge; Romero, Luís C; García, Irene; Gotor, Cecilia; León, José

    2011-01-07

    The last step of sulfur assimilation is catalyzed by O-acetylserine(thiol)lyase (OASTL) enzymes. OASTLs are encoded by a multigene family in the model plant Arabidopsis thaliana. Cytosolic OASA1 enzyme is the main source of OASTL activity and thus crucial for cysteine homeostasis. We found that nitrating conditions after exposure to peroxynitrite strongly inhibited OASTL activity. Among OASTLs, OASA1 was markedly sensitive to nitration as demonstrated by the comparative analysis of OASTL activity in nitrated crude protein extracts from wild type and different oastl mutants. Furthermore, nitration assays on purified recombinant OASA1 protein led to 90% reduction of the activity due to inhibition of the enzyme, as no degradation of the protein occurred under these conditions. The reduced activity was due to nitration of the protein because selective scavenging of peroxynitrite with epicatechin impaired OASA1 nitration and the concomitant inhibition of OASTL activity. Inhibition of OASA1 activity upon nitration correlated with the identification of a modified OASA1 protein containing 3-nitroTyr(302) residue. The essential role of the Tyr(302) residue for the catalytic activity was further demonstrated by the loss of OASTL activity of a Y302A-mutated version of OASA1. Inhibition caused by Tyr(302) nitration on OASA1 activity seems to be due to a drastically reduced O-acetylserine substrate binding to the nitrated protein, and also to reduced stabilization of the pyridoxal-5'-phosphate cofactor through hydrogen bonds. This is the first report identifying a Tyr nitration site of a plant protein with functional effect and the first post-translational modification identified in OASA1 enzyme.

  11. Selectivity of commonly used pharmacological inhibitors for cystathionine β synthase (CBS) and cystathionine γ lyase (CSE).

    Science.gov (United States)

    Asimakopoulou, Antonia; Panopoulos, Panagiotis; Chasapis, Christos T; Coletta, Ciro; Zhou, Zongmin; Cirino, Giuseppe; Giannis, Athanassios; Szabo, Csaba; Spyroulias, Georgios A; Papapetropoulos, Andreas

    2013-06-01

    Hydrogen sulfide (H₂S) is a signalling molecule that belongs to the gasotransmitter family. Two major sources for endogenous enzymatic production of H₂S are cystathionine β synthase (CBS) and cystathionine γ lyase (CSE). In the present study, we examined the selectivity of commonly used pharmacological inhibitors of H₂S biosynthesis towards CSE and CBS. To address this question, human CSE or CBS enzymes were expressed and purified from Escherichia coli as fusion proteins with GSH-S-transferase. After purification, the activity of the recombinant enzymes was tested using the methylene blue method. β-Cyanoalanine (BCA) was more potent in inhibiting CSE than propargylglycine (PAG) (IC₅₀ 14 ± 0.2 μM vs. 40 ± 8 μM respectively). Similar to PAG, L-aminoethoxyvinylglycine (AVG) only inhibited CSE, but did so at much lower concentrations. On the other hand, aminooxyacetic acid (AOAA), a frequently used CBS inhibitor, was more potent in inhibiting CSE compared with BCA and PAG (IC₅₀ 1.1 ± 0.1 μM); the IC₅₀ for AOAA for inhibiting CBS was 8.5 ± 0.7 μM. In line with our biochemical observations, relaxation to L-cysteine was blocked by AOAA in aortic rings that lacked CBS expression. Trifluoroalanine and hydroxylamine, two compounds that have also been used to block H₂S biosynthesis, blocked the activity of CBS and CSE. Trifluoroalanine had a fourfold lower IC₅₀ for CBS versus CSE, while hydroxylamine was 60-fold more selective against CSE. In conclusion, although PAG, AVG and BCA exhibit selectivity in inhibiting CSE versus CBS, no selective pharmacological CBS inhibitor is currently available. © 2013 The Authors. British Journal of Pharmacology © 2013 The British Pharmacological Society.

  12. Pyruvate formate lyase acts as a formate supplier for metabolic processes during anaerobiosis in Staphylococcus aureus.

    Science.gov (United States)

    Leibig, Martina; Liebeke, Manuel; Mader, Diana; Lalk, Michael; Peschel, Andreas; Götz, Friedrich

    2011-02-01

    Previous studies demonstrated an upregulation of pyruvate formate lyase (Pfl) and NAD-dependent formate dehydrogenase (Fdh) in Staphylococcus aureus biofilms. To investigate their physiological role, we constructed fdh and pfl deletion mutants (Δfdh and Δpfl). Although formate dehydrogenase activity in the fdh mutant was lost, it showed little phenotypic alterations under oxygen-limited conditions. In contrast, the pfl mutant displayed pleiotropic effects and revealed the importance of formate production for anabolic metabolism. In the pfl mutant, no formate was produced, glucose consumption was delayed, and ethanol production was decreased, whereas acetate and lactate production were unaffected. All metabolic alterations could be restored by addition of formate or complementation of the Δpfl mutant. In compensation reactions, serine and threonine were consumed better by the Δpfl mutant than by the wild type, suggesting that their catabolism contributes to the refilling of formyl-tetrahydrofolate, which acts as a donor of formyl groups in, e.g., purine and protein biosynthesis. This notion was supported by reduced production of formylated peptides by the Δpfl mutant compared to that of the parental strain, as demonstrated by weaker formyl-peptide receptor 1 (FPR1)-mediated activation of leukocytes with the mutant. FPR1 stimulation could also be restored either by addition of formate or by complementation of the mutation. Furthermore, arginine consumption and arc operon transcription were increased in the Δpfl mutant. Unlike what occurred with the investigated anaerobic conditions, a biofilm is distinguished by nutrient, oxygen, and pH gradients, and we thus assume that Pfl plays a significant role in the anaerobic layer of a biofilm. Fdh might be critical in (micro)aerobic layers, as formate oxidation is correlated with the generation of NADH/H(+), whose regeneration requires respiration.

  13. The roles of active site residues in the catalytic mechanism of methylaspartate ammonia-lyase.

    Science.gov (United States)

    Raj, Hans; Poelarends, Gerrit J

    2013-01-01

    Methylaspartate ammonia-lyase (MAL; EC 4.3.1.2) catalyzes the reversible addition of ammonia to mesaconate to yield l-threo-(2S,3S)-3-methylaspartate and l-erythro-(2S,3R)-3-methylaspartate as products. In the proposed minimal mechanism for MAL of Clostridium tetanomorphum, Lys-331 acts as the (S)-specific base catalyst and abstracts the 3S-proton from l-threo-3-methylaspartate, resulting in an enolate anion intermediate. This enolic intermediate is stabilized by coordination to the essential active site Mg(2+) ion and hydrogen bonding to the Gln-329 residue. Collapse of this intermediate results in the release of ammonia and the formation of mesaconate. His-194 likely acts as the (R)-specific base catalyst and abstracts the 3R-proton from the l-erythro isomer of 3-methylaspartate, yielding the enolic intermediate. In the present study, we have investigated the importance of the residues Gln-73, Phe-170, Gln-172, Tyr-356, Thr-360, Cys-361 and Leu-384 for the catalytic activity of C. tetanomorphum MAL. These residues, which are part of the enzyme surface lining the substrate binding pocket, were subjected to site-directed mutagenesis and the mutant enzymes were characterized for their structural integrity, ability to catalyze the amination of mesaconate, and regio- and diastereoselectivity. Based on the observed properties of the mutant enzymes, combined with previous structural studies and protein engineering work, we propose a detailed catalytic mechanism for the MAL-catalyzed reaction, in which the side chains of Gln-73, Gln-172, Tyr-356, Thr-360, and Leu-384 provide favorable interactions with the substrate, which are important for substrate binding and activation. This detailed knowledge of the catalytic mechanism of MAL can serve as a guide for future protein engineering experiments.

  14. The role of active site tyrosine 58 in Citrobacter freundii methionine γ-lyase.

    Science.gov (United States)

    Anufrieva, Natalya V; Faleev, Nicolai G; Morozova, Elena A; Bazhulina, Natalia P; Revtovich, Svetlana V; Timofeev, Vladimir P; Tkachev, Yaroslav V; Nikulin, Alexei D; Demidkina, Tatyana V

    2015-09-01

    In the spatial structure of methionine γ-lyase (MGL, EC 4.4.1.11) from Citrobacter freundii, Tyr58 is located at H-bonding distance to the oxygen atom of the phosphate "handle" of pyridoxal 5'-phosphate (PLP). It was replaced for phenylalanine by site-directed mutagenesis. The X-ray structure of the mutant enzyme was determined at 1.96Å resolution. Comparison of spatial structures and absorption spectra of wild-type and mutant holoenzymes demonstrated that the replacement did not result in essential changes of the conformation of the active site Tyr58Phe MGL. The Kd value of PLP for Tyr58Phe MGL proved to be comparable to the Kd value for the wild-type enzyme. The replacement led to a decrease of catalytic efficiencies in both γ- and β-elimination reactions of about two orders of magnitude as compared to those for the wild-type enzyme. The rates of exchange of C-α- and C-β- protons of inhibitors in D2O catalyzed by the mutant form are comparable with those for the wild-type enzyme. Spectral data on the complexes of the mutant form with the substrates and inhibitors showed that the replacement led to a change of rate the limiting step of the physiological reaction. The results allowed us to conclude that Tyr58 is involved in an optimal positioning of the active site Lys210 at some stages of γ- and β-elimination reactions. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.

  15. Simultaneous determination of the lipoxygenase and hydroperxide lyase specificity in olive fruit pulp

    Directory of Open Access Journals (Sweden)

    Salas, Joaquín J.

    2000-06-01

    Full Text Available Olive pulp lipoxygenase regiospecificity and hydroperoxide lyase substrate specificity are important parameters in order to justify the volatile composition of olive oil. A new radiolabelling method to determine simultaneously these properties using only thin layer chromatography steps is described in the present work. The method involves incubation of an enzyme preparation from olive pulp with radiolabelled linoleate, followed by the fractionation of the resulting lipid products, previously treated with 2,4-dinitrophenyl hydrazine, on thin layer chromatography plates coated with polyethylenglycol 400. The results obtained are in agreement with previous studies carried out by other methods.La regioespecificidad de la lipoxigenasa y la especificidad del sustrato hidroperóxido liasa de pulpa de aceituna son parámetros importantes en la justificación de la composición en volátiles del aceite de oliva. En este trabajo se describe un nuevo método de marcaje radioactivo para determinar simultáneamente estas propiedades, usando solo etapas de cromatografía en capa fina. El método implica la incubación de una preparación enzimática de pulpa de aceituna con linoleato marcado, seguido del fraccionamiento de los productos lipídicos resultantes, previamente tratados con 2,4-dinitrofenil hidrazina, sobre placas de cromatografía en capa fina soportadas con polietilenglicol 400. Los resultados obtenidos están de acuerdo con estudios previos llevados a cabo con otros métodos.

  16. Phenylalanine ammonia-lyase gene families incucurbit species:Structure, evolution, and expression

    Institute of Scientific and Technical Information of China (English)

    DONG Chun-juan; CAO Ning; ZHANG Zhi-gang; SHANG Qing-mao

    2016-01-01

    Phenylalanine ammonia-lyase (PAL), the ifrst enzyme of phenylpropanoid pathway, is always encoded by multigene families in plants. In this study, using genome-wide searches, 13PAL genes in cucumber (CsPAL1–13) and 13PALsin melon (Cm-PAL1–13) were identiifed. In the corresponding genomes, ten of thesePAL genes were located in tandem in two clusters, while the others were widely dispersed in different chromosomes as a single copy. The protein sequences of CsPALs and CmPALs shared an overal high identity to each other. In our previous report, 12PAL genes were identiifed in watermelon (ClPAL1–12). Thereby, a total of 38 cucurbitPAL members were included. Here, a comprehensive comparison ofPAL gene families was performed among three cucurbit plants. The phylogenetic and syntenic analyses placed the cucurbit PALs as 11 CsPAL-CmPAL-ClPAL triples, of which ten triples were clustered into the dicot group, and the remaining one, CsPAL1-CmPAL8-ClPAL2, was grouped with gymnosperm PALs and might serve as an ancestor of cucurbit PALs. By comparing the syntenic relationships and gene structure of these PAL genes, the expansion of cucurbit PALfamilies might arise from a series of segmental and tandem duplications and intron insertion events. Furthermore, the expression proifling in different tissues suggested that different cucurbit PALs displayed divergent but overlapping expression proifles, and the CsPAL-CmPAL-ClPAL orthologs showed correlative expression patterns among three cucurbit plants. Taken together, this study provided an extensive description on the evolution and expression of cucurbit PAL gene families and might facilitate the further studies for elucidating the functions of PALs in cucurbit plants.

  17. ATP citrate lyase mediated cytosolic acetyl-CoA biosynthesis increases mevalonate production in Saccharomyces cerevisiae.

    Science.gov (United States)

    Rodriguez, Sarah; Denby, Charles M; Van Vu, T; Baidoo, Edward E K; Wang, George; Keasling, Jay D

    2016-03-03

    With increasing concern about the environmental impact of a petroleum based economy, focus has shifted towards greener production strategies including metabolic engineering of microbes for the conversion of plant-based feedstocks to second generation biofuels and industrial chemicals. Saccharomyces cerevisiae is an attractive host for this purpose as it has been extensively engineered for production of various fuels and chemicals. Many of the target molecules are derived from the central metabolite and molecular building block, acetyl-CoA. To date, it has been difficult to engineer S. cerevisiae to continuously convert sugars present in biomass-based feedstocks to acetyl-CoA derived products due to intrinsic physiological constraints-in respiring cells, the precursor pyruvate is directed away from the endogenous cytosolic acetyl-CoA biosynthesis pathway towards the mitochondria, and in fermenting cells pyruvate is directed towards the byproduct ethanol. In this study we incorporated an alternative mode of acetyl-CoA biosynthesis mediated by ATP citrate lyase (ACL) that may obviate such constraints. We characterized the activity of several heterologously expressed ACLs in crude cell lysates, and found that ACL from Aspergillus nidulans demonstrated the highest activity. We employed a push/pull strategy to shunt citrate towards ACL by deletion of the mitochondrial NAD(+)-dependent isocitrate dehydrogenase (IDH1) and engineering higher flux through the upper mevalonate pathway. We demonstrated that combining the two modifications increases accumulation of mevalonate pathway intermediates, and that both modifications are required to substantially increase production. Finally, we incorporated a block strategy by replacing the native ERG12 (mevalonate kinase) promoter with the copper-repressible CTR3 promoter to maximize accumulation of the commercially important molecule mevalonate. By combining the push/pull/block strategies, we significantly improved mevalonate

  18. Partial deficiency of sphingosine-1-phosphate lyase confers protection in experimental autoimmune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Andreas Billich

    Full Text Available BACKGROUND: Sphingosine-1-phosphate (S1P regulates the egress of T cells from lymphoid organs; levels of S1P in the tissues are controlled by S1P lyase (Sgpl1. Hence, Sgpl1 offers a target to block T cell-dependent inflammatory processes. However, the involvement of Sgpl1 in models of disease has not been fully elucidated yet, since Sgpl1 KO mice have a short life-span. METHODOLOGY: We generated inducible Sgpl1 KO mice featuring partial reduction of Sgpl1 activity and analyzed them with respect to sphingolipid levels, T-cell distribution, and response in models of inflammation. PRINCIPAL FINDINGS: The partially Sgpl1 deficient mice are viable but feature profound reduction of peripheral T cells, similar to the constitutive KO mice. While thymic T cell development in these mice appears normal, mature T cells are retained in thymus and lymph nodes, leading to reduced T cell numbers in spleen and blood, with a skewing towards increased proportions of memory T cells and T regulatory cells. The therapeutic relevance of Sgpl1 is demonstrated by the fact that the inducible KO mice are protected in experimental autoimmune encephalomyelitis (EAE. T cell immigration into the CNS was found to be profoundly reduced. Since S1P levels in the brain of the animals are unchanged, we conclude that protection in EAE is due to the peripheral effect on T cells, leading to reduced CNS immigration, rather than on local effects in the CNS. SIGNIFICANCE: The data suggest Sgpl1 as a novel therapeutic target for the treatment of multiple sclerosis.

  19. PhnJ – A novel radical SAM enzyme from the C–P lyase complex

    Directory of Open Access Journals (Sweden)

    Siddhesh S. Kamat

    2015-03-01

    Full Text Available PhnJ from the C–P lyase complex catalyzes the cleavage of the carbon–phosphorus bond in ribose-1-phosphonate-5-phosphate (PRPn to produce methane and ribose-1,2-cyclic-phosphate-5-phosphate (PRcP. This protein is a novel radical SAM enzyme that uses glycyl and thiyl radicals as reactive intermediates in the proposed reaction mechanism. The overall reaction is initiated with the reductive cleavage of S-adenosylmethionine (SAM by a reduced [4Fe–4S]1+-cluster to form an Ado-CH2∙ radical intermediate. This intermediate abstracts the proR hydrogen from Gly-32 of PhnJ to form Ado-CH3 and a glycyl radical. In the next step, there is hydrogen atom transfer from Cys-272 to the Gly-32 radical to generate a thiyl radical. The thiyl radical attacks the phosphorus center of the substrate, PRPn, to form a transient thiophosphonate radical intermediate. This intermediate collapses via homolytic C–P bond cleavage and hydrogen atom transfer from the proS hydrogen of Gly-32 to produce a thiophosphate intermediate, methane, and a radical intermediate at Gly-32. The final product, PRcP, is formed by nucleophilic attack of the C2-hydroxyl on the transient thiophosphate intermediate. This reaction regenerates the free thiol group of Cys-272. After hydrogen atom transfer from Cys-272 to the Gly-32 radical, the entire process is repeated with another substrate molecule without the use of another molecule of SAM or involvement from the [4Fe–4S]-cluster again.

  20. Formulation and PEGylation optimization of the therapeutic PEGylated phenylalanine ammonia lyase for the treatment of phenylketonuria

    Science.gov (United States)

    Bell, Sean M.; Wendt, Dan J.; Zhang, Yanhong; Long, Shinong; Tsuruda, Laurie; Zhao, Bin; Laipis, Phillip; Fitzpatrick, Paul A.

    2017-01-01

    Phenylketonuria (PKU) is a genetic metabolic disease in which the decrease or loss of phenylalanine hydroxylase (PAH) activity results in elevated, neurotoxic levels of phenylalanine (Phe). Due to many obstacles, PAH enzyme replacement therapy is not currently an option. Treatment of PKU with an alternative enzyme, phenylalanine ammonia lyase (PAL), was first proposed in the 1970s. However, issues regarding immunogenicity, enzyme production and mode of delivery needed to be overcome. Through the evaluation of PAL enzymes from multiple species, three potential PAL enzymes from yeast and cyanobacteria were chosen for evaluation of their therapeutic potential. The addition of polyethylene glycol (PEG, MW = 20,000), at a particular ratio to modify the protein surface, attenuated immunogenicity in an animal model of PKU. All three PEGylated PAL candidates showed efficacy in a mouse model of PKU (BTBR Pahenu2) upon subcutaneous injection. However, only PEGylated Anabaena variabilis (Av) PAL-treated mice demonstrated sustained low Phe levels with weekly injection and was the only PAL evaluated that maintained full enzymatic activity upon PEGylation. A PEGylated recombinant double mutant version of AvPAL (Cys503Ser/Cys565Ser), rAvPAL-PEG, was selected for drug development based on its positive pharmacodynamic profile and favorable expression titers. PEGylation was shown to be critical for rAvPAL-PEG efficacy as under PEGylated rAvPAL had a lower pharmacodynamic effect. rAvPAL and rAvPAL-PEG had poor stability at 4°C. L-Phe and trans-cinnamate were identified as activity stabilizing excipients. rAvPAL-PEG is currently in Phase 3 clinical trials to assess efficacy in PKU patients. PMID:28282402

  1. A carbon-nitrogen lyase from Leucaena leucocephala catalyzes the first step of mimosine degradation.

    Science.gov (United States)

    Negi, Vishal Singh; Bingham, Jon-Paul; Li, Qing X; Borthakur, Dulal

    2014-02-01

    The tree legume Leucaena leucocephala contains a large amount of a toxic nonprotein aromatic amino acid, mimosine, and also an enzyme, mimosinase, for mimosine degradation. In this study, we isolated a 1,520-bp complementary DNA (cDNA) for mimosinase from L. leucocephala and characterized the encoded enzyme for mimosine-degrading activity. The deduced amino acid sequence of the coding region of the cDNA was predicted to have a chloroplast transit peptide. The nucleotide sequence, excluding the sequence for the chloroplast transit peptide, was codon optimized and expressed in Escherichia coli. The purified recombinant enzyme was used in mimosine degradation assays, and the chromatogram of the major product was found to be identical to that of 3-hydroxy-4-pyridone (3H4P), which was further verified by electrospray ionization-tandem mass spectrometry. The enzyme activity requires pyridoxal 5'-phosphate but not α-keto acid; therefore, the enzyme is not an aminotransferase. In addition to 3H4P, we also identified pyruvate and ammonia as other degradation products. The dependence of the enzyme on pyridoxal 5'-phosphate and the production of 3H4P with the release of ammonia indicate that it is a carbon-nitrogen lyase. It was found to be highly efficient and specific in catalyzing mimosine degradation, with apparent Km and Vmax values of 1.16×10(-4) m and 5.05×10(-5) mol s(-1) mg(-1), respectively. The presence of other aromatic amino acids, including l-tyrosine, l-phenylalanine, and l-tryptophan, in the reaction did not show any competitive inhibition. The isolation of the mimosinase cDNA and the biochemical characterization of the recombinant enzyme will be useful in developing transgenic L. leucocephala with reduced mimosine content in the future.

  2. Transcriptional Regulation of Cystathionine-γ-Lyase in Endothelial Cells by NADPH Oxidase 4-Dependent Signaling*

    Science.gov (United States)

    Mistry, Rajesh K.; Murray, Thomas V. A.; Prysyazhna, Oleksandra; Martin, Daniel; Burgoyne, Joseph R.; Santos, Celio; Eaton, Philip; Shah, Ajay M.; Brewer, Alison C.

    2016-01-01

    The gasotransmitter, hydrogen sulfide (H2S) is recognized as an important mediator of endothelial cell homeostasis and function that impacts upon vascular tone and blood pressure. Cystathionine-γ-lyase (CSE) is the predominant endothelial generator of H2S, and recent evidence suggests that its transcriptional expression is regulated by the reactive oxygen species, H2O2. However, the cellular source of H2O2 and the redox-dependent molecular signaling pathway that modulates this is not known. We aimed to investigate the role of Nox4, an endothelial generator of H2O2, in the regulation of CSE in endothelial cells. Both gain- and loss-of-function experiments in human endothelial cells in vitro demonstrated Nox4 to be a positive regulator of CSE transcription and protein expression. We demonstrate that this is dependent upon a heme-regulated inhibitor kinase/eIF2α/activating transcription factor 4 (ATF4) signaling module. ATF4 was further demonstrated to bind directly to cis-regulatory sequences within the first intron of CSE to activate transcription. Furthermore, CSE expression was also increased in cardiac microvascular endothelial cells, isolated from endothelial-specific Nox4 transgenic mice, compared with wild-type littermate controls. Using wire myography we demonstrate that endothelial-specific Nox4 transgenic mice exhibit a hypo-contractile phenotype in response to phenylephrine that was abolished when vessels were incubated with a CSE inhibitor, propargylglycine. We, therefore, conclude that Nox4 is a positive transcriptional regulator of CSE in endothelial cells and propose that it may in turn contribute to the regulation of vascular tone via the modulation of H2S production. PMID:26620565

  3. Lactic acid bacteria involved in cocoa beans fermentation from Ivory Coast: Species diversity and citrate lyase production.

    Science.gov (United States)

    Ouattara, Hadja D; Ouattara, Honoré G; Droux, Michel; Reverchon, Sylvie; Nasser, William; Niamke, Sébastien L

    2017-09-01

    Microbial fermentation is an indispensable process for high quality chocolate from cocoa bean raw material. lactic acid bacteria (LAB) are among the major microorganisms responsible for cocoa fermentation but their exact role remains to be elucidated. In this study, we analyzed the diversity of LAB in six cocoa producing regions of Ivory Coast. Ribosomal 16S gene sequence analysis showed that Lactobacillus plantarum and Leuconostoc mesenteroides are the dominant LAB species in these six regions. In addition, other species were identified as the minor microbial population, namely Lactobacillus curieae, Enterococcus faecium, Fructobacillus pseudoficulneus, Lactobacillus casei, Weissella paramesenteroides and Weissella cibaria. However, in each region, the LAB microbial population was composed of a restricted number of species (maximum 5 species), which varied between the different regions. LAB implication in the breakdown of citric acid was investigated as a fundamental property for a successful cocoa fermentation process. High citrate lyase producer strains were characterized by rapid citric acid consumption, as revealed by a 4-fold decrease in citric acid concentration in the growth medium within 12h, concomitant with an increase in acetic acid and lactic acid concentration. The production of citrate lyase was strongly dependent on environmental conditions, with optimum production at acidic pH (pH<5), and moderate temperature (30-40°C), which corresponds to conditions prevailing in the early stage of natural cocoa fermentation. This study reveals that one of the major roles of LAB in the cocoa fermentation process involves the breakdown of citric acid during the early stage of cocoa fermentation through the activity of citrate lyase. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. New Mechanistic Insight from Substrate- and Product-Bound Structures of the Metal-Dependent Dimethylsulfoniopropionate Lyase DddQ.

    Science.gov (United States)

    Brummett, Adam E; Dey, Mishtu

    2016-11-08

    The marine microbial catabolism of dimethylsulfoniopropionate (DMSP) by the lyase pathway liberates ∼300 million tons of dimethyl sulfide (DMS) per year, which plays a major role in the biogeochemical cycling of sulfur. Recent biochemical and structural studies of some DMSP lyases, including DddQ, reveal the importance of divalent transition metal ions in assisting DMSP cleavage. While DddQ is believed to be zinc-dependent primarily on the basis of structural studies, excess zinc inhibits the enzyme. We examine the importance of iron in regulating the DMSP β-elimination reaction catalyzed by DddQ as our as-isolated purple-colored enzyme possesses ∼0.5 Fe/subunit. The UV-visible spectrum exhibited a feature at 550 nm, consistent with a tyrosinate-Fe(III) ligand-to-metal charge transfer transition. Incubation of as-isolated DddQ with added iron increases the intensity of the 550 nm peak, whereas addition of dithionite causes a bleaching as Fe(III) is reduced. Both the Fe(III) oxidized and Fe(II) reduced species are active, with similar kcat values and 2-fold differences in their Km values for DMSP. The slow turnover of Fe(III)-bound DddQ allowed us to capture a substrate-bound form of the enzyme. Our DMSP-Fe(III)-DddQ structure reveals conformational changes associated with substrate binding and shows that DMSP is positioned optimally to bind iron and is in the proximity of Tyr 120 that acts as a Lewis base to initiate catalysis. The structures of Tris-, DMSP-, and acrylate-bound forms of Fe(III)-DddQ reported here illustrate various states of the enzyme along the reaction pathway. These results provide new insights into DMSP lyase catalysis and have broader significance for understanding the mechanism of oceanic DMS production.

  5. 电子商务系统内的人力资源管理模式解析%The analytic model of human resource management in electronic commerce system

    Institute of Scientific and Technical Information of China (English)

    王斌

    2013-01-01

      企业人力资源管理工作在现代电子商务环境下呈现出多方面的电子化新特征,且较之于传统的人力资源管理工作有非常多显著的优势可言,基本上已经成为了企业获取更大成功的基本导向。电子商务系统内的人力资源管理新模式E-HR就是在这样一种背景下应运而生的,E-HR管理模式不仅已经成为了众多企业发展的趋势,而且在实际应用的过程当中也已经给企业带来了非常多的利益。本文正是在此背景之下对电子商务系统内的人力资源管理模式E-HR进行解析,希望能够对其有更深入的理解并更好的应用到实践当中去。%The enterprise human resources management in modern electronic commerce environment presents many new characteristics of the electron,and compared with the traditional human resource management has many significant advantages,basically has become a basic guide for more successful enterprises.E-HR is a new mode of human resource management system emerge as the times require electronic commerce is in such a background,the E-HR management model not only has become the trend of development of many enterprises, but also in the process of practical application also has to the enterprise has brought a lot of benefits. This paper is analyzed under this background to the electronic commerce system within the human resources management mode of E-HR,the application wishes to have a deeper understanding and better on it into practice.

  6. INFLUENCE OF COBALT IONS ON ENZYME ACTIVTY OF ISOCITRIATE LYASE AND ITS REGULATION IN CONDITION OF SEED GERMINATION OF GLYCINE MAX L.

    Directory of Open Access Journals (Sweden)

    Chechui O. F.

    2012-12-01

    Full Text Available We investigated the activity of isocitrate lyase in seeds of Glycine max L. after 24, 72, and 120 hours of germination and effect of cobalt ions on the activity of the enzyme in time limit of the experiment. We fixed the increase in the activity of isocitrate lyase under influence of cobalt ions occurs by means of enzyme induction on third day of experiment while maintaining performance of enzyme activity on the fifth day; one of the reasons caused the increased activity of the key enzyme of the glyoxylate cycle under the influence of cobalt ions can be increasing of the concentration of lipid peroxidation. In addition, during experiments with usage of actinomycin D we determined the increasing of activity ofisocitrate lyase under the influence of cobalt ions by enzyme induction.

  7. Positive Perceptions of Access to Online Library Resources Correlates with Quality and Quantity of Scholarly Publications among Finnish Academics. A Review of: Vakkari, Pertti. “Perceived Influence of the Use of Electronic Information Resources on Scholarly Work and Publication Productivity.” Journal of the American Society for Information Science and Technology 59.4 (Feb. 15, 2008: 602-12.

    Directory of Open Access Journals (Sweden)

    Scott Marsalis

    2008-12-01

    Full Text Available Objective – To investigate the relationship between academics’ use of library electronic resources and their opinions regarding how these resources have impacted their work, and to investigate the association between this perceived influence and publication productivity during the previous two years.Design – Two specific questions added to an annual online user-survey questionnaire; additional data mined from surveySetting – Twenty-two Finnish Universities served by FinELib, the Finnish Electronic Library.Subjects – Seven hundred and sixty seven academic staff and full-time doctoral students.Methods – A questionnaire was posted in April 2007 on FinELib’s homepage and advertised on each university library’s mainpage, and focused on respondents’ experience in the previous two years. Participants selected answers either from a list of category choices, or, when measuring perceptions, by rating agreement with statements along a four-point scale. Controlled variables measured were the respondents’ academic position, their discipline, membership in a research group, whether their literature use was discipline-specific or interdisciplinary, and their perception of the availability online of the relevant core literature. The independent variable measured was the scholars’ perception of the impact of the use of electronic library resources on their work. The dependent variable measured was the scholars’ self-reported publications in the two years preceding the survey.Main Results – Participants reported a positive impact on the efficiency of their work, most strongly in areas of ease of access, with lesser impacts in the range of materials available to them and the ease with which they can keep up-to-date in their field. To a lesser extent, the scholars perceived a positive impact on the quality of their work. Upon analysis, the study found that access to online library resources improved scholars’ work by the interconnected

  8. Discovery of the Selective CYP17A1 Lyase Inhibitor BMS-351 for the Treatment of Prostate Cancer.

    Science.gov (United States)

    Huang, Audris; Jayaraman, Lata; Fura, Aberra; Vite, Gregory D; Trainor, George L; Gottardis, Marco M; Spires, Thomas E; Spires, Vanessa M; Rizzo, Cheryl A; Obermeier, Mary T; Elzinga, Paul A; Todderud, Gordon; Fan, Yi; Newitt, John A; Beyer, Sophie M; Zhu, Yongxin; Warrack, Bethanne M; Goodenough, Angela K; Tebben, Andrew J; Doweyko, Arthur M; Gold, David L; Balog, Aaron

    2016-01-14

    Efforts to identify a potent, reversible, nonsteroidal CYP17A1 lyase inhibitor with good selectivity over CYP17A1 hydroxylase and CYPs 11B1 and 21A2 for the treatment of castration-resistant prostate cancer (CRPC) culminated in the discovery of BMS-351 (compound 18), a pyridyl biaryl benzimidazole with an excellent in vivo profile. Biological evaluation of BMS-351 at a dose of 1.5 mg in castrated cynomolgus monkeys revealed a remarkable reduction in testosterone levels with minimal glucocorticoid and mineralcorticoid perturbation. Based on a favorable profile, BMS-351 was selected as a candidate for further preclinical evaluation.

  9. Molecular cloning and characterization of an Erwinia carotovora subsp. carotovora pectin lyase gene that responds to DNA-damaging agents.

    OpenAIRE

    McEvoy, J L; Murata, H.; Chatterjee, A. K.

    1990-01-01

    recA-mediated production of pectin lyase (PNL) and the bacteriocin carotovoricin occurs in Erwinia carotovora subsp. carotovora 71 when this organism is subjected to agents that damage or inhibit the synthesis of DNA. The structural gene pnlA was isolated from a strain 71 cosmid gene library following mobilization of the cosmids into a moderate PNL producer, strain 193. The cosmid complemented pnl::Tn5 but not ctv::Tn5 mutations. A constitutive level of PNL activity was detected in RecA+ and ...

  10. Effects of pectin lyase-modified red ginseng extracts in high-fat diet-fed obese mice

    OpenAIRE

    Lee, Hak-Yong; Park, Kwang-Hyun; PARK, Young-mi; Moon, Dae-In; Oh, Hong-Geun; Kwon, Dae-Young; Yang, Hye-Jeong; Kim, Okjin; Kim, Dong-Woo; Yoo, Ji-Hyun; Hong, Se-Chul; Lee, Kun-Hee; Seol, Su-Yeon; Park, Yong-Sik; Park, Jong-Dae

    2014-01-01

    Red ginseng and its extracts have been used as traditional medicines and functional foods in countries worldwide. The aim of this study was to examine the bioavailability of pectin lyase-modified red ginseng extracts (GS-E3D), and the effects of GS-E3D on adipogenesis of 3T3-L1 adipocytes, as well as on metabolic disorders such as hyperglycemia, dyslipidemia, and fatty liver in high-fat diet fed obese C57BL/6 mice. Mice were divided into 5 groups: normal diet group, high fat diet-vehicle grou...

  11. Structure of PhnP: a phosphodiesterase of the carbon-phosphorous lyase pathway for phosphonate degradation

    DEFF Research Database (Denmark)

    Podzelinska, Kateryna; He, Shu-Mei; Wathier, Matthew;

    2009-01-01

    similar to that of the tRNase Z endonucleases but lacks the long exosite module used by these enzymes to bind their tRNA substrates. The active site of PhnP contains what are probably two Mn2+ ions surrounded by an array of active site residues that are identical to those observed in the tRNase Z enzymes......Carbon-phosphorus lyase is a multienzyme system encoded by the phn operon that enables bacteria to metabolize organophosphonates when the preferred nutrient, inorganic phosphate, is scarce. One of the enzymes encoded by this operon, PhnP, is predicted by sequence homology to be a metal...

  12. Sunlight-stimulated phenylalanine ammonia-lyase (PAL activity and anthocyanin accumulation in exocarp of ‘Mahajanaka’ mango

    Directory of Open Access Journals (Sweden)

    Kobkiat Saengnil

    2011-11-01

    Full Text Available The activity of phenylalanine ammonia-lyase (PAL required for anthocyanin synthesis was stimulated by sunlight exposure resulting in the development of red colour in ‘Mahajanaka’ mango exocarp, which occurred only on the sunlight-exposed side of the fruit. The accumulation of anthocyanin was concurrent with the increase in PAL activity in the mature stage of the fruit. The exposed side of the fruit had higher PAL activity, endogenous sugar content, and anthocyanin accumulation than the unexposed side. It is concluded that sunlight increases red colour development of the mango exocarp by inducing PAL activity. Exposure to sunlight also enhances endogenous sugar accumulation in mango fruit.

  13. Elicitor modulation of the turnover of L-phenylalanine ammonia-lyase in French bean cell suspension cultures.

    Science.gov (United States)

    Lawton, M A; Dixon, R A; Lamb, C J

    1980-12-01

    (1) The mechanisms underlying the transient increase in phenylalanine ammonia-lyase activity during phaseollin accumulation in cell suspension cultures of Dwarf French bean (Phaseolus volgaris) have been investigated using density labelling with 3H from 2H2O coupled with residual analysis of the equilibrium distribution of enzyme activity in high-resolution KBr density gradients. (2) The resolution achieved in this system is sufficient to allow quantitative analysis of the relative proportions of light, unlabelled, pre-existing enzyme and heavy, labelled, newly synthesised enzyme. (3) Elicitor released by heat treatment of cell walls of Colletotrichum lindemuthianum, the causal agent of anthracnose disease of French bean, caused a marked but transient increase in phenylalanine ammonia-lyase activity concomitant with the onset of phaseollin accumulation in the bean cultures. The induction of enzyme activity was highly dependent on elicitor concentration, with maximum induction occurring in two discrete concentration ranges; at an intermediate elicitor concentration, or at supra-optimal elicitor concentrations, no enzyme induction was observed. (4) At low concentrations of elicitor the induction of enzyme was entirely a result of elicitor stimulation of the rate of de novo enzyme production. In contrast, at higher elicitor concentrations the increase in enzyme activity was accompanied by a marked apparent stabilization of the enzyme in vivo, and the rapid but transient increase in enzyme activity was achieved by a programme of reciprocal changes in the rate constant for de novo enzyme production and the rate constant for removal of enzyme activity. Such reciprocal control of the rates of enzyme production and removal may be crucial in determining the magnitude and duration of the phytoalexin defense response. (5) Information on the specific activity of 2H label in the amino acid pools was obtained from analysis of the equilibrium distribution of residual, labelled

  14. Complementation of a phycocyanin-bilin lyase from Synechocystis sp. PCC 6803 with a nucleomorph-encoded open reading frame from the cryptophyte Guillardia theta

    Directory of Open Access Journals (Sweden)

    Nyalwidhe Julius

    2008-05-01

    Full Text Available Abstract Background Cryptophytes are highly compartmentalized organisms, expressing a secondary minimized eukaryotic genome in the nucleomorph and its surrounding remnant cytoplasm, in addition to the cell nucleus, the mitochondrion and the plastid. Because the members of the nucleomorph-encoded proteome may contribute to essential cellular pathways, elucidating nucleomorph-encoded functions is of utmost interest. Unfortunately, cryptophytes are inaccessible for genetic transformations thus far. Therefore the functions of nucleomorph-encoded proteins must be elucidated indirectly by application of methods in genetically accessible organisms. Results Orf222, one of the uncharacterized nucleomorph-specific open reading frames of the cryptophyte Guillardia theta, shows homology to slr1649 of Synechocystis sp. PCC 6803. Recently a further homolog from Synechococcus sp. PCC 7002 was characterized to encode a phycocyanin-β155-bilin lyase. Here we show by insertion mutagenesis that the Synechocystis sp. PCC 6803 slr1649-encoded protein also acts as a bilin lyase, and additionally contributes to linker attachment and/or stability of phycobilisomes. Finally, our results indicate that the phycocyanin-β155-bilin lyase of Synechocystis sp. PCC 6803 can be complemented in vivo by the nucleomorph-encoded open reading frame orf222. Conclusion Our data show that the loss of phycocyanin-lyase function causes pleiotropic effects in Synechocystis sp. PCC 6803 and indicate that after separating from a common ancestor protein, the phycoerythrin lyase from Guillardia theta has retained its capacity to couple a bilin group to other phycobiliproteins. This is a further, unexpected example of the universality of phycobiliprotein lyases.

  15. Lactation resources for clinicians.

    Science.gov (United States)

    Turner-Maffei, Cynthia

    2007-01-01

    Breastfeeding is widely acknowledged as the optimal infant feeding choice. However, many clinicians working in maternal and child health do not receive adequate university preparation to support breastfeeding. Knowledge and skill are most often gained through on-the-job and personal experience. Myriad resources exist to support clinicians in delivering the best quality care to breastfeeding clients. Among the available resources are policies and protocols of professional organizations, governmental, and health advocacy groups. Breastfeeding-focused academic and continuing education programs are identified. Electronic and other resources for breastfeeding information are available for both professional and consumer audiences.

  16. Renewable energy resources

    DEFF Research Database (Denmark)

    Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

    2014-01-01

    Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

  17. Merge of terminological resources

    DEFF Research Database (Denmark)

    Henriksen, Lina; Braasch, Anna

    2012-01-01

    In our globalized world, the amount of cross-national communication increases rapidly, which also calls for easy access to multi-lingual high quality terminological resources. Sharing of terminology resources is currently becoming common practice, and efficient strategies for integration...... – or merging – of terminology resources are strongly needed. This paper discusses prerequisites for successful merging with the focus on identification of candidate duplicates of a subject domain found in the resources to be merged, and it describes automatic merging strategies to be applied to such duplicates...... in electronic terminology resources. Further, some perspectives of manual, supplementary assessment methods supporting the automatic procedures are sketched. Our considerations are primarily based on experience gained in the IATE and EuroTermBank projects, as merging was a much discussed issue in both projects....

  18. Crystallization and preliminary X-ray analysis of l-methionine γ-lyase 1 from Entamoeba histolytica

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Dan [Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052 (Japan); Center for Integrated Medical Research, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Karaki, Tsuyoshi; Shimizu, Akira; Kamei, Kaeko; Harada, Shigeharu, E-mail: harada@kit.ac.jp [Graduate School of Science and Technology, Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Nozaki, Tomoyoshi [Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640 (Japan); Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052 (Japan)

    2008-08-01

    l-Methionine γ-lyase 1, a key enzyme in sulfur-containing amino-acid degradation, from the protozoan parasite E. histolytica was crystallized in a form suitable for X-ray structure analysis. l-Methionine γ-lyase (MGL) is a pyridoxal phosphate-dependent enzyme that is involved in the degradation of sulfur-containing amino acids. MGL is an attractive drug target against amoebiasis because the mammalian host of its causative agent Entamoeba histolytica lacks MGL. For the development of anti-amoebic agents based on the structure of MGL, one of two MGL isoenzymes (EhMGL1) was crystallized in the monoclinic space group P2{sub 1}, with unit-cell parameters a = 99.12, b = 85.38, c = 115.37 Å, β = 101.82°. The crystals diffract to beyond 2.0 Å resolution. The presence of a tetramer in the asymmetric unit (4 × 42.4 kDa) gives a Matthews coefficient of 2.8 Å{sup 3} Da{sup −1} and a solvent content of 56%. The structure was solved by the molecular-replacement method and structure refinement is now in progress.

  19. Two Novel Alliin Lyase (Alliinase Genes from Twisted-Leaf Garlic (Allium obliquum and Mountain Garlic (Allium senescens ssp. montanum

    Directory of Open Access Journals (Sweden)

    Nicolae DRAGOŞ

    2011-11-01

    Full Text Available Alliinase (Alliin lyase EC 4.4.1.4, a pyridoxal phosphate-dependent lyase, represents one of the major protein components of Allium species. The enzyme is a homodimeric glycoprotein and catalyzes the synthesis of allicin (diallyl thiosulfinate, a biologically active compound, pyruvate, and ammonia starting from the specific non-protein sulfur-containing amino acid alliin ((+S-allyl-L-cysteine sulfoxide. Using newly developed specific primers two new alliinase genes from Allium obliquum and Allium senescens ssp. montanum were amplified and sequenced, as well as their homologs, from Allium fistulosum and Allium schoenoprasum. The G+C content of the alliinase region ranges between that of other dicot plants and that reported in monocot cereal plants, in all four species. Investigations of gene expression revealed a significantly higher enzyme expression level in bulbs than in leaves in all four taxa. The deduced alliinase sequences displayed a high variability among different species, since the lowest sequence similarity was found to be 55.5% between Allium senescens ssp. montanum and Allium cepa, while the highest similarity is 77.5%, between Allium senescens ssp. montanum and Allium fistulosum. Leucine is the most common amino acid in all four alliinases, while cysteine is also more frequent than in other enzymes, suggesting a high stability of the molecules due to the possible disulfide bonds.

  20. Two Novel Alliin Lyase (Alliinase Genes from Twisted-Leaf Garlic (Allium obliquum and Mountain Garlic (Allium senescens var. montanum

    Directory of Open Access Journals (Sweden)

    Bogdan DRUGĂ

    2011-11-01

    Full Text Available Alliinase (Alliin lyase EC 4.4.1.4, a pyridoxal phosphate-dependent lyase, represents one of the major protein components of Allium species. The enzyme is a homodimeric glycoprotein and catalyzes the synthesis of allicin (diallyl thiosulfinate, a biologically active compound, pyruvate, and ammonia starting from the specific non-protein sulfur-containing amino acid alliin ((+S-allyl-L-cysteine sulfoxide. Using newly developed specific primers two new alliinase genes from Allium obliquum and Allium senescens ssp. montanum were amplified and sequenced, as well as their homologs, from Allium fistulosum and Allium schoeonoprasum. The G+C content of the alliinase region ranges between that of other dicot plants and that reported in monocot cereal plants, in all four species. Investigations of gene expression revealed a significantly higher enzyme expression level in bulbs than in leaves in all four taxa. The deduced alliinase sequences displayed a high variability among different species, since the lowest sequence similarity was found to be 55.5% between Allium senescens var. montanum and Allium cepa, while the highest similarity is 77.5%, between Allium senescens var. montanum and Allium fistulosum. Leucine is the most common amino acid in all four alliinases, while cysteine is also more frequent that in other enzymes, suggesting a high stability of the molecules due to the possible disulfide bonds.

  1. Dehydroepiandrosterone formation is independent of cytochrome P450 17alpha-hydroxylase/17, 20 lyase activity in the mouse brain.

    Science.gov (United States)

    Liu, Ying; Pocivavsek, Ana; Papadopoulos, Vassilios

    2009-07-01

    Cytochrome P450 17alpha-hydroxylase/17, 20 lyase (CYP17) is a microsomal enzyme reported to have two distinct catalytic activities, 17alpha-hydroxylase and 17, 20 lyase, that are essential for the biosynthesis of peripheral androgens such as dehydroepiandrosterone (DHEA). Paradoxically, DHEA is present and plays a role in learning and memory in the adult rodent brain, while CYP17 activity and protein are undetectable. To determine if CYP17 is required for DHEA formation and function in the adult rodent brain, we generated CYP17 chimeric mice that had reduced circulating testosterone levels. There were no detectable differences in cognitive spatial learning between CYP17 chimeric and wild-type mice. In addition, while CYP17 mRNA levels were reduced in CYP17 chimeric compared to wild-type mouse brain, the levels of brain DHEA levels were comparable. To determine if adult brain DHEA is formed by an alternative Fe(2+)-dependent pathway, brain microsomes were isolated from wild-type and CYP17 chimeric mice and treated with FeSO(4). Fe(2+) caused comparable levels of DHEA production by both wild-type and CYP17 chimeric mouse brain microsomes; DHEA production was not reduced by a CYP17 inhibitor. Taken together these in vivo studies suggest that in the adult mouse brain DHEA is formed via a Fe(2+)-sensitive CYP17-independent pathway.

  2. Structural Snapshots of an Engineered Cystathionine-γ-lyase Reveal the Critical Role of Electrostatic Interactions in the Active Site

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Wupeng; Stone, Everett; Zhang, Yan Jessie

    2017-02-01

    Enzyme therapeutics that can degrade l-methionine (l-Met) are of great interest as numerous malignancies are exquisitely sensitive to l-Met depletion. To exhaust the pool of methionine in human serum, we previously engineered an l-Met-degrading enzyme based on the human cystathionine-γ-lyase scaffold (hCGL-NLV) to circumvent immunogenicity and stability issues observed in the preclinical application of bacterially derived methionine-γ-lyases. To gain further insights into the structure–activity relationships governing the chemistry of the hCGL-NLV lead molecule, we undertook a biophysical characterization campaign that captured crystal structures (2.2 Å) of hCGL-NLV with distinct reaction intermediates, including internal aldimine, substrate-bound, gem-diamine, and external aldimine forms. Curiously, an alternate form of hCGL-NLV that crystallized under higher-salt conditions revealed a locally unfolded active site, correlating with inhibition of activity as a function of ionic strength. Subsequent mutational and kinetic experiments pinpointed that a salt bridge between the phosphate of the essential cofactor pyridoxal 5'-phosphate (PLP) and residue R62 plays an important role in catalyzing β- and γ-eliminations. Our study suggests that solvent ions such as NaCl disrupt electrostatic interactions between R62 and PLP, decreasing catalytic efficiency.

  3. Stereochemical course of the generation of 3-mercaptohexanal and 3-mercaptohexanol by beta-lyase-catalyzed cleavage of cysteine conjugates.

    Science.gov (United States)

    Wakabayashi, Hidehiko; Wakabayashi, Motoko; Eisenreich, Wolfgang; Engel, Karl-Heinz

    2004-01-14

    The product resulting from the reaction between E-2-hexenal and l-cysteine was shown to be a diastereoisomeric mixture of 2-(2-S-l-cysteinylpentyl)-1,3-thiazolidine-4-carboxylic acid 1. Treatment of the conjugate with two sources of cysteine-S-conjugate beta-lyase (tryptophanase from E. coli and a crude enzyme extract prepared from Eubacterium limosum) resulted in the formation of 3-mercaptohexanal. The reaction proceeded with a slight preference for the (S)-configured product, however, with low conversion rate. The role of 3-S-l-cysteinylhexanal 2 as substrate for beta-lyases was demonstrated by in situ generation of 2 from 3-S-(N-acetyl-l-cysteinyl)hexanal using acylase. Opposite enantioselectivity was observed for the liberation of 3-mercaptohexanol from 3-S-l-cysteinylhexanol 5 by the enzyme preparations from Eubacterium limosum and tryptophanase. Various yeasts produced 3-mercaptohexanol starting from 1 as well as from 5. The reactions proceeded without preferential formation of one of the enantiomers.

  4. Lactoylglutathione lyase, a critical enzyme in methylglyoxal detoxification, contributes to survival of Salmonella in the nutrient rich environment

    Science.gov (United States)

    Chakraborty, Sangeeta; Gogoi, Mayuri; Chakravortty, Dipshikha

    2015-01-01

    Glyoxalase I which is synonymously known as lactoylglutathione lyase is a critical enzyme in methylglyoxal (MG) detoxification. We assessed the STM3117 encoded lactoylglutathione lyase (Lgl) of Salmonella Typhimurium, which is known to function as a virulence factor, due in part to its ability to detoxify methylglyoxal. We found that STM3117 encoded Lgl isomerises the hemithioacetal adduct of MG and glutathione (GSH) into S-lactoylglutathione. Lgl was observed to be an outer membrane bound protein with maximum expression at the exponential growth phase. The deletion mutant of S. Typhimurium (Δlgl) exhibited a notable growth inhibition coupled with oxidative DNA damage and membrane disruptions, in accordance with the growth arrest phenomenon associated with typical glyoxalase I deletion. However, growth in glucose minimal medium did not result in any inhibition. Endogenous expression of recombinant Lgl in serovar Typhi led to an increased resistance and growth in presence of external MG. Being a metalloprotein, Lgl was found to get activated maximally by Co2+ ion followed by Ni2+, while Zn2+ did not activate the enzyme and this could be attributed to the geometry of the particular protein-metal complex attained in the catalytically active state. Our results offer an insight on the pivotal role of the virulence associated and horizontally acquired STM3117 gene in non-typhoidal serovars with direct correlation of its activity in lending survival advantage to Salmonella spp. PMID:25517857

  5. Comparison of expression, purification and characterization of a new pectate lyase from Phytophthora capsici using two different methods

    Directory of Open Access Journals (Sweden)

    Zhang Xiuguo

    2011-04-01

    Full Text Available Abstract Background Pectate lyases (PELs play an important role in the infection process of plant pathogens and also have a commercial significance in industrial applications. Most of the PELs were expressed as soluble recombinant proteins, while a few recombinant proteins were insoluble. The production of a large-scale soluble recombinant PEL would allow not only a more detailed structural and functional characterization of this enzyme but also may have important applications in the food industry. Results We cloned a new pectate lyase gene (Pcpel2 from Phytophthora capsici. Pcpel2 was constructed by pET system and pMAL system, and both constructs were used to express the PCPEL2 in Escherichia coli BL21 (DE3 pLysS. The expressed products were purified using affinity chromatography and gel filtration chromatography. The purity, specific activity and pathogenicity of the purified PCPEL2 expressed by the pMAL system were higher than the purified PCPEL2 expressed by the pET system. In addition, some other characteristics of the purified PCPEL2 differed from the two systems, such as crystallographic features. Purified PCPEL2 expressed by the pMAL system was crystallized by the hanging-drop vapour-diffusion method at 289 K, and initial crystals were grown. Conclusion The two different methods and comparison presented here would be highly valuable in obtaining an ideal enzyme for the downstream experiments, and supply an useful alternative to purify some insoluble recombinant proteins.

  6. Evaluating the use of a simulated electronic health record and online drug reference in a case study to enhance nursing students' understanding of pharmacologic concepts and resources.

    Science.gov (United States)

    Vana, Kimberly D; Silva, Graciela E

    2014-01-01

    Nursing students should learn to navigate the complexities of the healthcare arena, such as integrating use of electronic health records (EHRs) and online drug references into patient care. Using a simulated EHR in a nursing pharmacology course allowed students to interact with these technologies while learning and applying pharmacologic concepts to a case study. The authors discuss how they created and facilitated such a case study, as well as students' outcomes.

  7. Essential histidine pairs indicate conserved haem binding in epsilonproteobacterial cytochrome c haem lyases.

    Science.gov (United States)

    Kern, Melanie; Scheithauer, Juliane; Kranz, Robert G; Simon, Jörg

    2010-12-01

    Bacterial cytochrome c maturation occurs at the outside of the cytoplasmic membrane, requires transport of haem b across the membrane, and depends on membrane-bound cytochrome c haem lyase (CCHL), an enzyme that catalyses covalent attachment of haem b to apocytochrome c. Epsilonproteobacteria such as Wolinella succinogenes use the cytochrome c biogenesis system II and contain unusually large CCHL proteins of about 900 amino acid residues that appear to be fusions of the CcsB and CcsA proteins found in other bacteria. CcsBA-type CCHLs have been proposed to act as haem transporters that contain two haem b coordination sites located at different sides of the membrane and formed by histidine pairs. W. succinogenes cells contain three CcsBA-type CCHL isoenzymes (NrfI, CcsA1 and CcsA2) that are known to differ in their specificity for apocytochromes and apparently recognize different haem c binding motifs such as CX(2)CH (by CcsA2), CX(2)CK (by NrfI) and CX(15)CH (by CcsA1). In this study, conserved histidine residues were individually replaced by alanine in each of the W. succinogenes CCHLs. Characterization of NrfI and CcsA1 variants in W. succinogenes demonstrated that a set of four histidines is essential for maturing the dedicated multihaem cytochromes c NrfA and MccA, respectively. The function of W. succinogenes CcsA2 variants produced in Escherichia coli was also found to depend on each of these four conserved histidine residues. The presence of imidazole in the growth medium of both W. succinogenes and E. coli rescued the cytochrome c biogenesis activity of most histidine variants, albeit to different extents, thereby implying the presence of two functionally distinct histidine pairs in each CCHL. The data support a model in which two conserved haem b binding sites are involved in haem transport catalysed by CcsBA-type CCHLs.

  8. 浅谈高职院校图书馆电子资源的管理和服务%On the Management and Service of the Electronic Resources of Higher Vocational College Library

    Institute of Scientific and Technical Information of China (English)

    邓正芳

    2014-01-01

    Under the background of rapid development of social economy, the computer technology, computer network technology, communication technology, database technology and other information technology, China has entered the information age ahead of time. In higher vocational colleges, the library electronic resources have become an important way for teachers and students to get teaching knowledge and scientific research information, providing reliable, timely and accurate books resources information service for teachers and students. In order to ensure the effective utilization of library electronic resources in higher vocational colleges, scientific and reasonable management is necessary, so as to promote the construction of digital libraries in higher vocational colleges, to achieve better and faster development.%在社会经济的快速发展背景下,我国计算机技术、计算机网络技术、通讯技术以及数据库技术等信息技术的产生,使我国提前进入信息化时代。在高职院校中,图书馆电子资源已经成为老师和学生获取教学知识、科研信息等方面的重要途径,为学校老师和学生提供了可靠、及时、准确的图书资源信息化服务。为了确保高职院校图书馆电子资源的有效利用,需要对其进行科学合理的管理,促进高职院校图书馆数字化建设,使其更好更快地发展。

  9. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  10. Electronic collection management

    CERN Document Server

    Mcginnis, Suzan D

    2013-01-01

    Build and manage your collection of digital resources with these successful strategies! This comprehensive volume is a practical guide to the art and science of acquiring and organizing electronic resources. The collections discussed here range in size from small college libraries to large research libraries, but all are facing similar problems: shrinking budgets, increasing demands, and rapidly shifting formats. Electronic Collection Management offers new ideas for coping with these issues. Bringing together diverse aspects of collection development, Electronic Collection

  11. 基于高校图书馆电子资源的采访调查与分析——以海南大学图书馆为例%Survey and Analysis Based on the Electronic Resource of University Libraries Taking Hainan University library as an Example

    Institute of Scientific and Technical Information of China (English)

    杨莹

    2011-01-01

    随着信息化时代的到来,高校图书馆的馆藏资源建设模式已经发生了变化,形成了纸质资源与电子资源并存的局面,电子资源以其方便快捷深受读者喜爱,电子资源的采购比例越来越重,如何协调电子资源的采购比例,是图书馆界丞待解决的问题.文章通过对海南大学2006-2010年间的电子资源经费使用情况进行统计、对比和分析,对此问题进行了初步的探讨.%With the arrival of information age, college library collection resources construction mode has changed, and the paper-based resources and electroic resources coexist.With the convenience of electronic resources, the acquisition proportion of electronic resources grows.How to coordinate the acquisition of electronic resource proportion is a problem faced by the libraries.Through the funds statistics, contrast and analysis of electronic resources in hainan university 2006-2010 this article provides a preliminary discussion.

  12. EFFECTIVE ELECTRONIC TUTORIAL

    Directory of Open Access Journals (Sweden)

    Andrei A. Fedoseev

    2014-01-01

    Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

  13. Silencing of grapevine pectate lyase-like genes VvPLL2 and VvPLL3 confers resistance against Erysiphe necator and differentially modulates gene expression

    Science.gov (United States)

    Broad-spectrum resistance against powdery mildew (PM) has been reported by silencing susceptibility genes in the model plant Arabidopsis. Here we used artificial microRNA constructs in PM-susceptible Vitis vinifera cv. Chardonnay to stably silence two pectate lyase-like orthologs (VvPLL2 and VvPLL3)...

  14. A mutation in the cytosolic O-acetylserine (thiol) lyase induces a genome-dependent early leaf death phenotype in Arabidopsis

    NARCIS (Netherlands)

    Shirzadian-Khorramabad, Reza; Jing, Hai-Chun; Everts, Gerja E.; Schippers, Jos H. M.; Hille, Jacques; Dijkwel, Paul P.

    2010-01-01

    Background: Cysteine is a component in organic compounds including glutathione that have been implicated in the adaptation of plants to stresses. O-acetylserine (thiol) lyase (OAS-TL) catalyses the final step of cysteine biosynthesis. OAS-TL enzyme isoforms are localised in the cytoplasm, the plasti

  15. Correlation of Rutin Accumulation with 3-O-Glucosyl Transferase and Phenylalanine Ammonia-lyase Activities During the Ripening of Tomato Fruit

    NARCIS (Netherlands)

    Capanoglu, E.; Beekwilder, J.; Matros, A.; Boyacioglu, D.; Hall, R.D.; Mock, H.P.

    2012-01-01

    In tomato, the predominant flavonoid is quercetin-3-rutinoside (rutin). In this study, we aim to investigate the phenylalanine ammonia-lyase (PAL) and the quercetin-3-O-glucosyl transferase (3-GT) reactions in the formation of rutin during tomato fruit ripening. Tomatoes of the Moneymaker variety at

  16. Mutation R96W in cytochrome P450c17 gene causes combined 17{alpha}-hydroxylase/17-20-lyase deficiency in two french canadian patients

    Energy Technology Data Exchange (ETDEWEB)

    LaFlamme, N.; Leblanc, J.F.; Mailloux, J. [Laval Univ., Quebec (Canada)

    1996-01-01

    Congenital adrenal hyperplasia (CAH) is the most frequent cause of adrenal insufficiency and ambiguous genitalia in newborn children. In contrast to CAH caused by 21{alpha}-hydroxylase and 11{beta}-hydroxylase deficiencies, which impairs steroid formation in the adrenal exclusively, 17{alpha}-hydroxylase/17,20-lyase deficiency impairs steroid biosynthesis in the adrenals and gonads. The sequence of CYP17 gene was determined by direct sequencing of asymmetric PCR products in two French-Canadian 46,XY pseudohermaphrodite siblings suffering from combined 17{alpha}-hydroxylase/17,20-lyase deficiency. The two patients are homozygous for the novel missense mutation R96W caused by a C to T transition converting codon Arg{sup 96} (CGG) into a Trp (TGG) in exon 1. Both parents are heterozygous for this missense mutation. We assessed the effect of the R96W mutation on 17{alpha}-hydroxylase/17,20-lyase activity by analysis of mutant enzyme, generated by site-directed mutagenesis, expressed in COS-1 cells. The presence of R96W substitution almost completely abolished the activity of the mutant protein. The present findings provide a molecular explanation for the signs and symptoms of combined 17 {alpha}-hydroxylase/17,20-lyase deficiency in these two patients and provide useful information on the structure-activity relationships of the P450c17 enzyme. 31 refs., 4 figs., 1 tab.

  17. Modification of potato cell wall pectin by the introduction of rhamnogalacturonan lyase and β-galactosidase transgenes and their side effects

    NARCIS (Netherlands)

    Huang, Jie Hong; Kortstee, Anne; Dees, Dianka C.T.; Trindade, Luisa M.; Schols, Henk A.; Gruppen, Harry

    2016-01-01

    Genes encoding pectic enzymes were introduced to wild-type potato Karnico. Cell wall materials were extracted from Karnico and transgenic lines expressing β-galactosidase (β-Gal-14 mutant) or rhamnogalacturonan lyase (RGL-18 mutant). After sequential extraction, β-Gal-14 hot buffer-soluble solids

  18. The structure of RdDddP from Roseobacter denitrificans reveals that DMSP lyases in the DddP-family are metalloenzymes.

    Directory of Open Access Journals (Sweden)

    Jan-Hendrik Hehemann

    Full Text Available Marine microbes degrade dimethylsulfoniopropionate (DMSP, which is produced in large quantities by marine algae and plants, with DMSP lyases into acrylate and the gas dimethyl sulfide (DMS. Approximately 10% of the DMS vents from the sea into the atmosphere and this emission returns sulfur, which arrives in the sea through rivers and runoff, back to terrestrial systems via clouds and rain. Despite their key role in this sulfur cycle DMSP lyases are poorly understood at the molecular level. Here we report the first X-ray crystal structure of the putative DMSP lyase RdDddP from Roseobacter denitrificans, which belongs to the abundant DddP family. This structure, determined to 2.15 Å resolution, shows that RdDddP is a homodimeric metalloprotein with a binuclear center of two metal ions located 2.7 Å apart in the active site of the enzyme. Consistent with the crystallographic data, inductively coupled plasma mass spectrometry (ICP-MS and total reflection X-ray fluorescence (TRXF revealed the bound metal species to be primarily iron. A 3D structure guided analysis of environmental DddP lyase sequences elucidated the critical residues for metal binding are invariant, suggesting all proteins in the DddP family are metalloenzymes.

  19. Effects of phenylalanine ammonia lyase (PAL) knockdown on cell wall composition, biomass digestibility, and biotic and abiotic stress responses in Brachypodium

    Science.gov (United States)

    Phenylalanine Ammonia Lyase (PAL) catalyzes the first step in the phenylpropanoid pathway in plants, controlling biosynthesis of a variety of structural and defense compounds including monolignols that polymerize into lignin. Gaps remain in our understanding of how genetic alterations to this pathwa...

  20. L-Phenylalanine ammonia-lyase from Phaseolus vulgaris. Characterisation and differential induction of multiple forms from elicitor-treated cell suspension cultures.

    Science.gov (United States)

    Bolwell, G P; Bell, J N; Cramer, C L; Schuch, W; Lamb, C J; Dixon, R A

    1985-06-03

    L-Phenylalanine ammonia-lyase (EC 4.3.1.5) has been purified over 200-fold from cell cultures of bean (phaseolus vulgaris L.) exposed to elicitor heat-released from the cell walls of the phytopathogenic fungus Colletotrichum lindemuthianum. Four forms of the enzyme, with identical Mr but differing apparent pI values of 5.4, 5.2, 5.05 and 4.85, were observed following the final chromatofocussing stage of the purification. A preparation (purified 43-fold by ammonium sulphate precipitation, gel-filtration and ion-exchange chromatography) containing all four forms exhibited apparent negative rate cooperativity with respect to substrates. However, the individual forms displayed normal Michaelis-Menten kinetics, with Km values of 0.077 mM, 0.122 mM, 0.256 mM and 0.302 mM in order of decreasing apparent pI value. A preparation purified 200-fold and containing all four forms was used to immunise rabbits for the production of anti-(phenylalanine ammonia-lyase) serum. The antiserum was characterised by: immunotitration experiments; solid phase enzyme-linked immunosorbent assays; comparison of immunoprecipitates of 35S-labelled phenylalanine ammonia-lyase subunits (synthesized both in vivo and in vitro) on both one-dimensional and two-dimensional polyacrylamide gels after immunoprecipitation with the bean antiserum or antisera raised against pea and parsley phenylalanine ammonia-lyase preparations and immune blotting. SDS/polyacrylamide gels and SDS/polyacrylamide gel electrophoresis followed by immune blotting, indicated that the Mr of newly synthesized (in vivo and in vitro) bean phenylalanine ammonia-lyase subunits is 77000; a 70000-Mr form is readily generated as a partial degradation product during purification. Immunoprecipitates of bean phenylalanine ammonia-lyase synthesized both in vivo and in vitro showed the presence of multiple subunit types of identical Mr but differing in pI. Furthermore, treatment of bean cultures with Colletotrichum elicitor resulted in a 10

  1. The pectate lyase encoded by the pecCl1 gene is an important determinant for the aggressiveness of Colletotrichum lindemuthianum.

    Science.gov (United States)

    Cnossen-Fassoni, Andréia; Bazzolli, Denise Mara Soares; Brommonschenkel, Sérgio Hermínio; Fernandes de Araújo, Elza; de Queiroz, Marisa Vieira

    2013-08-01

    Colletotrichum lindemuthianum is the causal agent of anthracnose in the common bean, and the genes that encode its cell-wall-degrading enzymes are crucial for the development of the disease. Pectinases are the most important group of cell wall-degrading enzymes produced by phytopathogenic fungi. The pecC1l gene, which encodes a pectate lyase in C. lindemuthianum, was isolated and characterized. Possible cis-regulatory elements and transcription factor binding sites that may be involved in the regulation of genetic expression were detected in the promoter region of the gene. pecCl1 is represented by a single copy in the genome of C. lindemuthianum, though in silico analyses of the genomes of Colletotrichum graminicola and Colletotrichum higginsianum suggest that the genome of C. lindemuthianum includes other genes that encode pectate lyases. Phylogenetic analysis detected two groups that clustered based on different members of the pectate lyase family. Analysis of the differential expression of pecCl1 during different stages of infection showed a significant increase in pecCl1 expression five days after infection, at the onset of the necrotrophic phase. The split-maker technique proved to be an efficient method for inactivation of the pecCl1 gene, which allowed functional study of a mutant with a site-specific integration. Though gene inactivation did not result in complete loss of pectate lyase activity, the symptoms of anthracnose were reduced. Analysis of pectate lyases might not only contribute to the understanding of anthracnose in the common bean but might also lead to the discovery of an additional target for controlling anthracnose.

  2. Mechanistic pathways of mercury removal from the organomercurial lyase active site

    Directory of Open Access Journals (Sweden)

    Pedro J. Silva

    2015-07-01

    Full Text Available Bacterial populations present in Hg-rich environments have evolved biological mechanisms to detoxify methylmercury and other organometallic mercury compounds. The most common resistance mechanism relies on the H+-assisted cleavage of the Hg–C bond of methylmercury by the organomercurial lyase MerB. Although the initial reaction steps which lead to the loss of methane from methylmercury have already been studied experimentally and computationally, the reaction steps leading to the removal of Hg2+ from MerB and regeneration of the active site for a new round of catalysis have not yet been elucidated. In this paper, we have studied the final steps of the reaction catalyzed by MerB through quantum chemical computations at the combined MP2/CBS//B3PW91/6-31G(d level of theory. While conceptually simple, these reaction steps occur in a complex potential energy surface where several distinct pathways are accessible and may operate concurrently. The only pathway which clearly emerges as forbidden in our analysis is the one arising from the sequential addition of two thiolates to the metal atom, due to the accumulation of negative charges in the active site. The addition of two thiols, in contrast, leads to two feasible mechanistic possibilities. The most straightforward pathway proceeds through proton transfer from the attacking thiol to Cys159 , leading to its removal from the mercury coordination sphere, followed by a slower attack of a second thiol, which removes Cys96. The other pathway involves Asp99 in an accessory role similar to the one observed earlier for the initial stages of the reaction and affords a lower activation enthalpy, around 14 kcal mol−1, determined solely by the cysteine removal step rather than by the thiol ligation step. Addition of one thiolate to the intermediates arising from either thiol attack occurs without a barrier and produces an intermediate bound to one active site cysteine and from which Hg(SCH32 may be removed

  3. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...

  4. Study of time-lapse processing for dynamic hydrologic conditions. [electronic satellite image analysis console for Earth Resources Technology Satellites imagery

    Science.gov (United States)

    Serebreny, S. M.; Evans, W. E.; Wiegman, E. J.

    1974-01-01

    The usefulness of dynamic display techniques in exploiting the repetitive nature of ERTS imagery was investigated. A specially designed Electronic Satellite Image Analysis Console (ESIAC) was developed and employed to process data for seven ERTS principal investigators studying dynamic hydrological conditions for diverse applications. These applications include measurement of snowfield extent and sediment plumes from estuary discharge, Playa Lake inventory, and monitoring of phreatophyte and other vegetation changes. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The most unique feature of the system is the capability to time lapse the imagery and analytic displays of the imagery. Data products included quantitative measurements of distances and areas, binary thematic maps based on monospectral or multispectral decisions, radiance profiles, and movie loops. Applications of animation for uses other than creating time-lapse sequences are identified. Input to the ESIAC can be either digital or via photographic transparencies.

  5. Polyphenol Oxidase, Peroxidase and Phenylalanine Ammonium Lyase Induced in Postharvest Peach Fruits by Inoculation with Pichia membranefaciens or Rhizopus stolonifer

    Institute of Scientific and Technical Information of China (English)

    QIN Guo-zheng; TIAN Shi-ping; LIU Hai-bo; XU Yong

    2002-01-01

    Rhizopus rot of peach fruits could be significantly suppressed by Pichia membranefaciens.Polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonium-lyase (PAL) activities inducedby inoculation with P. membranefaciens or R. stolonifer were studied in postharvest peach fruits. The activ-ities of PPO and PAL in peaches increased significantly after being inoculated with P. membranefaciens + R.stolonifer by 24 h, the activities maintained at a high level throughout the experiment. Under the condition ofinfected with R. stolonifer alone, activity of PPO and PAL could also increased, but the levels were lowerthan those treated with P. membranefaciens+ R. stolonifer. However, fruits inoculaed with P. membrane-faciens+ R. stolonifer or R. stolonifer alone did not stimulated POD activity. The results suggest that theactivation of these defense enzymes is involved in the action of P. membranefaciens against R. stolonifer.

  6. Studies on the inhibition of sphingosine-1-phosphate lyase by stabilized reaction intermediates and stereodefined azido phosphates.

    Science.gov (United States)

    Sanllehí, Pol; Abad, José-Luís; Bujons, Jordi; Casas, Josefina; Delgado, Antonio

    2016-11-10

    Two kinds of inhibitors of the PLP-dependent enzyme sphingosine-1-phosphate lyase have been designed and tested on the bacterial (StS1PL) and the human (hS1PL) enzymes. Amino phosphates 1, 12, and 32, mimicking the intermediate aldimines of the catalytic process, were weak inhibitors on both enzyme sources. On the other hand, a series of stereodefined azido phosphates, resulting from the replacement of the amino group of the natural substrates with an azido group, afforded competitive inhibitors in the low micromolar range on both enzyme sources. This similar behavior represents an experimental evidence of the reported structural similarities for both enzymes at their active site level. Interestingly, the anti-isomers of the non-natural enantiomeric series where the most potent inhibitors on hS1PL.

  7. Pre-steady-state kinetic and structural analysis of interaction of methionine γ-lyase from Citrobacter freundii with inhibitors.

    Science.gov (United States)

    Kuznetsov, Nikita A; Faleev, Nicolai G; Kuznetsova, Alexandra A; Morozova, Elena A; Revtovich, Svetlana V; Anufrieva, Natalya V; Nikulin, Alexei D; Fedorova, Olga S; Demidkina, Tatyana V

    2015-01-01

    Methionine γ-lyase (MGL) catalyzes the γ-elimination of l-methionine and its derivatives as well as the β-elimination of l-cysteine and its analogs. These reactions yield α-keto acids and thiols. The mechanism of chemical conversion of amino acids includes numerous reaction intermediates. The detailed analysis of MGL interaction with glycine, l-alanine, l-norvaline, and l-cycloserine was performed by pre-steady-state stopped-flow kinetics. The structure of side chains of the amino acids is important both for their binding with enzyme and for the stability of the external aldimine and ketimine intermediates. X-ray structure of the MGL·l-cycloserine complex has been solved at 1.6 Å resolution. The structure models the ketimine intermediate of physiological reaction. The results elucidate the mechanisms of the intermediate interconversion at the stages of external aldimine and ketimine formation.

  8. Structural dynamics of a methionine γ-lyase for calicheamicin biosynthesis: Rotation of the conserved tyrosine stacking with pyridoxal phosphate

    Directory of Open Access Journals (Sweden)

    Hongnan Cao

    2016-05-01

    Full Text Available CalE6 from Micromonospora echinospora is a (pyridoxal 5′ phosphate PLP-dependent methionine γ-lyase involved in the biosynthesis of calicheamicins. We report the crystal structure of a CalE6 2-(N-morpholinoethanesulfonic acid complex showing ligand-induced rotation of Tyr100, which stacks with PLP, resembling the corresponding tyrosine rotation of true catalytic intermediates of CalE6 homologs. Elastic network modeling and crystallographic ensemble refinement reveal mobility of the N-terminal loop, which involves both tetrameric assembly and PLP binding. Modeling and comparative structural analysis of PLP-dependent enzymes involved in Cys/Met metabolism shine light on the functional implications of the intrinsic dynamic properties of CalE6 in catalysis and holoenzyme maturation.

  9. Structural dynamics of a methionine γ-lyase for calicheamicin biosynthesis: Rotation of the conserved tyrosine stacking with pyridoxal phosphate.

    Science.gov (United States)

    Cao, Hongnan; Tan, Kemin; Wang, Fengbin; Bigelow, Lance; Yennamalli, Ragothaman M; Jedrzejczak, Robert; Babnigg, Gyorgy; Bingman, Craig A; Joachimiak, Andrzej; Kharel, Madan K; Singh, Shanteri; Thorson, Jon S; Phillips, George N

    2016-05-01

    CalE6 from Micromonospora echinospora is a (pyridoxal 5' phosphate) PLP-dependent methionine γ-lyase involved in the biosynthesis of calicheamicins. We report the crystal structure of a CalE6 2-(N-morpholino)ethanesulfonic acid complex showing ligand-induced rotation of Tyr100, which stacks with PLP, resembling the corresponding tyrosine rotation of true catalytic intermediates of CalE6 homologs. Elastic network modeling and crystallographic ensemble refinement reveal mobility of the N-terminal loop, which involves both tetrameric assembly and PLP binding. Modeling and comparative structural analysis of PLP-dependent enzymes involved in Cys/Met metabolism shine light on the functional implications of the intrinsic dynamic properties of CalE6 in catalysis and holoenzyme maturation.

  10. Enzymatic changes in phenylalanine ammonia-lyase, cinnamic-4-hydroxylase, capsaicin synthase, and peroxidase activities in capsicum under drought stress.

    Science.gov (United States)

    Phimchan, Paongpetch; Chanthai, Saksit; Bosland, Paul W; Techawongstien, Suchila

    2014-07-23

    Penylalanine ammonia-lyase (PAL), cinnamic-4-hydroxylase (C4H), capsaicin synthase (CS), and peroxidase (POD) are involved in the capsaicinoid biosynthesis pathway and may be altered in cultivars with different pungency levels. This study clarified the action of these enzymes under drought stress for hot Capsicum cultivars with low, medium,and high pungency levels. At the flowering stage, control plants were watered at field capacity, whereas drought-induced plants were subjected to gradual drought stress. Under drought stress, PAL, C4H, CS, and POD enzyme activities increased as compared to the non-drought-stressed plants. A novel discovery was that PAL was the critical enzyme in capsaicinoid biosynthesis under drought stress because its activities and capsaicinoid increased across the different pungency levels of hot pepper cultivars examined.

  11. Phytochrome-mediated induction of phenylalanine ammonia-lyase in the cotyledons of tomato (Lycopersicon esculentum Mill.) plants.

    Science.gov (United States)

    Lercari, B; Sodi, F; Fastami, C

    1982-01-01

    Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5.) induction in cotyledons from 96-h dark-grown Lycopersicon esculentum Mill. was studied in response to continuous light and hourly light pulses (blue, red, far red). The increases of PAL promoted by blue and red pulses are reversed completely by immediately following 758 nm irradiations. The response to continuous red light could be substituted for by hourly 6-min red light pulses. The effect of continuous red treatments is mainly due to a multiple induction effect of phytochrome. In contrast to red light, hourly light pulses with far red and blue, light can only partially substitute for continuous irradiation. The continuous blue response could be due to a combination of a multiple induction response and of a high irradiance response of phytochrome. The continuous far red response, could represent a high irradiance response of phytochrome. Dichromatic irradiations indicate that phytochrome is the photoreceptor controlling the light response (PAL) in tomato seedlings.

  12. Establishment of chondroitin B lyase-based analytical methods for sensitive and quantitative detection of dermatan sulfate in heparin.

    Science.gov (United States)

    Wu, Jingjun; Ji, Yang; Su, Nan; Li, Ye; Liu, Xinxin; Mei, Xiang; Zhou, Qianqian; Zhang, Chong; Xing, Xin-hui

    2016-06-25

    Dermatan sulfate (DS) is one of the hardest impurities to remove from heparin products due to their high structural similarity. The development of a sensitive and feasible method for quantitative detection of DS in heparin is essential to ensure the clinical safety of heparin pharmaceuticals. In the current study, based on the substrate specificity of chondroitin B lyase, ultraviolet spectrophotometric and strong anion-exchange high-performance liquid chromatographic methods were established for detection of DS in heparin. The former method facilitated analysis in heparin with DS concentrations greater than 0.1mgmL(-1) at 232nm, with good linearity, precision and recovery. The latter method allowed sensitive and accurate detection of DS at concentrations lower than 0.1mgmL(-1), exhibiting good linearity, precision and recovery. The linear range of DS detection using the latter method was between 0.01 and 0.5mgmL(-1).

  13. Enhancement of cell viability and alkaline polygalacturonate lyase production by sorbitol co-feeding with methanol in Pichia pastoris fermentation.

    Science.gov (United States)

    Wang, Zhihao; Wang, Yun; Zhang, Dongxu; Li, Jianghua; Hua, Zhaozhe; Du, Guocheng; Chen, Jian

    2010-02-01

    Alkaline polygalacturonate lyase (PGL) production by Pichia pastoris GS115 was used as a model to study the mechanism and strategy for enhancing heterologous protein production. In order to enhance cell viability and volumetric recombinant protein productivity, sorbitol, which had been confirmed to be a non-repressive carbon source, was added together with methanol during the induction phase. The resultant PGL activity was up to 1593 U mL(-1), which was enhanced 1.85-fold compared to the control (863 U mL(-1)) cultured with sorbitol added at a constant rate of 3.6 g h(-1)L(-1) after an induction period of 100 h. Further results revealed that an appropriate sorbitol co-feeding strategy not only decreased the cell mortality to 8.8% (the control is about 23.1%) in the end of fermentation, but also reduced the proteolytic degradation of PGL.

  14. Molecular Basis of C–N Bond Cleavage by the Glycyl Radical Enzyme Choline Trimethylamine-Lyase

    Energy Technology Data Exchange (ETDEWEB)

    Bodea, Smaranda; Funk, Michael A.; Balskus, Emily P.; Drennan, Catherine L.

    2016-10-01

    We report that deamination of choline catalyzed by the glycyl radical enzyme choline trimethylamine-lyase (CutC) has emerged as an important route for the production of trimethylamine, a microbial metabolite associated with both human disease and biological methane production. Here, we have determined five high-resolution X-ray structures of wild-type CutC and mechanistically informative mutants in the presence of choline. Within an unexpectedly polar active site, CutC orients choline through hydrogen bonding with a putative general base, and through close interactions between phenolic and carboxylate oxygen atoms of the protein scaffold and the polarized methyl groups of the trimethylammonium moiety. These structural data, along with biochemical analysis of active site mutants, support a mechanism that involves direct elimination of trimethylamine. Lastly, this work broadens our understanding of radical-based enzyme catalysis and will aid in the rational design of inhibitors of bacterial trimethylamine production.

  15. Analysis of promoter activity of members of the PECTATE LYASE-LIKE (PLL) gene family in cell separation in Arabidopsis.

    Science.gov (United States)

    Sun, Lingxia; van Nocker, Steven

    2010-07-22

    Pectate lyases depolymerize pectins by catalyzing the eliminative cleavage of alpha-1,4-linked galacturonic acid. Pectate lyase-like (PLL) genes make up among the largest and most complex families in plants, but their cellular and organismal roles have not been well characterized, and the activity of these genes has been assessed only at the level of entire organs or plant parts, potentially obscuring important sub-organ or cell-type-specific activities. As a first step to understand the potential functional diversity of PLL genes in plants and specificity of individual genes, we utilized a reporter gene approach to document the spatial and temporal promoter activity for 23 of the 26 members of the Arabidopsis thaliana (Arabidopsis) PLL gene family throughout development, focusing on processes involving cell separation. Numerous PLL promoters directed activity in localized domains programmed for cell separation, such as the abscission zones of the sepal, petal, stamen, and seed, as well as the fruit dehiscence zone. Several drove activity in cell types expected to facilitate separation, including the style and root endodermal and cortical layers during lateral root emergence. However, PLL promoters were active in domains not obviously programmed for separation, including the stipule, hydathode and root axis. Nearly all PLL promoters showed extensive overlap of activity in most of the regions analyzed. Our results document potential for involvement of PLL genes in numerous aspects of growth and development both dependent and independent of cell separation. Although the complexity of the PLL gene family allows for enormous potential for gene specialization through spatial or temporal regulation, the high degree of overlap of activity among the PLL promoters suggests extensive redundancy. Alternatively, functional specialization might be determined at the post-transcriptional or protein level.

  16. Resource Manual

    Science.gov (United States)

    Human Development Institute, 2008

    2008-01-01

    This manual was designed primarily for use by individuals with developmental disabilities and related conditions. The main focus of this manual is to provide easy-to-read information concerning available resources, and to provide immediate contact information for the purpose of applying for resources and/or locating additional information. The…

  17. Rethinking Resourcing.

    Science.gov (United States)

    Norris, Donald M.; Olson, Mark A.

    2003-01-01

    This adaptation of an excerpt from a book, "The Business Value Web: Resourcing Business Processes and Solutions in Higher Education," addresses ways to look at college business processes systematically, take fresh approaches to resourcing, and create real value for stakeholders. (EV)

  18. Assessment of use of library resources on research activities of ...

    African Journals Online (AJOL)

    Open Access DOWNLOAD FULL TEXT ... Library resources use contribute immensely to the research output of agricultural scientists and ... electronics Library resources such as electronic journals, e-books, scholarly databases, ... researchers to have access to a wide range of high quality electronic information resources.

  19. Genetic toxicology: web resources.

    Science.gov (United States)

    Young, Robert R

    2002-04-25

    Genetic toxicology is the scientific discipline dealing with the effects of chemical, physical and biological agents on the heredity of living organisms. The Internet offers a wide range of online digital resources for the field of Genetic Toxicology. The history of genetic toxicology and electronic data collections are reviewed. Web-based resources at US National Library of Medicine (NLM), including MEDLINE, PUBMED, Gateway, Entrez, and TOXNET, are discussed. Search strategies and Medical Subject Headings (MeSH) are reviewed in the context of genetic toxicology. The TOXNET group of databases are discussed with emphasis on those databases with genetic toxicology content including GENE-TOX, TOXLINE, Hazardous Substances Data Bank, Integrated Risk Information System, and Chemical Carcinogenesis Research Information System. Location of chemical information including chemical structure and linkage to health and regulatory information using CHEMIDPLUS at NLM and other databases is reviewed. Various government agencies have active genetic toxicology research programs or use genetic toxicology data to assist fulfilling the agency's mission. Online resources at the US Food and Drug Administration (FDA), the US Environmental Protection Agency (EPA), the National Institutes of Environmental Health Sciences, and the National Toxicology Program (NTP) are outlined. Much of the genetic toxicology for pharmaceuticals, industrial chemicals and pesticides that is performed in the world is regulatory-driven. Regulatory web resources are presented for the laws mandating testing, guidelines on study design, Good Laboratory Practice (GLP) regulations, and requirements for electronic data collection and reporting. The Internet provides a range of other supporting resources to the field of genetic toxicology. The web links for key professional societies and journals in genetic toxicology are listed. Distance education, educational media resources, and job placement services are also

  20. 地方高校的电子文献资源建设——以南京晓庄学院为例%Construction of Electronic Literature Resources of Local University Library —— A Case Study ofNanjing Xiaozhuang University

    Institute of Scientific and Technical Information of China (English)

    王雯

    2012-01-01

    以南京晓庄学院图书馆为蓝本,从电子资源的文献价值入手,阐明了编制电子资源的采访标准和评价指标的意义,指出在当前网络环境下,地方高校加强电子文献资源建设的重要性和发展方向。%This paper is on the original version ofNanjing Xiaozhuang University library, from the literature value of electron- ic resource, expounds the meaning of compiling electronic resources acquisition standard and evaluation index, points out under current network environment, the importance of local university library strengthen electronic litera-ture resources construction and development direction.