Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | PubMed Central |
|---|---|
| Author | Rogowski, R. S. Krueger, B. K. Collins, J. H. Blaustein, M. P. |
| Abstract | Two nonhomologous polypeptide toxins, tityustoxinK alpha (TsTX-K alpha) and tityustoxin K beta (TsTX-K beta), purified from thevenom of the Brazilian scorpion Tityus serrulatus, selectively blockvoltage-gated noninactivating K+ channels in synaptosomes (IC50 values of 8 nMand 30 nM, respectively). In contrast, alpha-dendrotoxin (alpha-DTX) andcharybdotoxin (ChTX) block voltage-gated inactivating K+ channels insynaptosomes (IC50 values of 90 nM and 40 nM, respectively). We studiedinteractions among these toxins in 125I-alpha-DTX binding and 86Rb effluxexperiments. Both TsTX-K alpha and ChTX completely displaced specifically bound125I-alpha-DTX from synaptic membranes, but TsTX-K beta had no effect on boundalpha-DTX. TsTX-K alpha and TsTX-K beta blocked the same noninactivatingcomponent of 100 mM K(+)-stimulated 86Rb efflux in synaptosomes. Both alpha-DTXand ChTX blocked the same inactivating component of the K(+)-stimulated 86Rbefflux in synaptosomes. Both the inactivating and the noninactivating componentsof the 100 mM K(+)-stimulated 86Rb efflux were completely blocked when 200 nMTsTX-K beta and either 600 nM alpha-DTX or 200 nM ChTX were present. The effectsof TsTX-K alpha and ChTX on 86Rb efflux were also additive. When TsTX-K alphawas added in the presence of alpha-DTX, however, only the noninactivatingcomponent of the K(+)-stimulated efflux was blocked. The inactivating componentcould then be blocked by ChTX, which is structurally homologous to TsTX-K alpha.We conclude that TsTX-K alpha unblocks the voltage-gated inactivating K+channels in synaptosomes when they are blocked by alpha-DTX, but not when theyare blocked by ChTX. TsTX-K alpha binds to a site on the inactivating K+ channelthat does not occlude the pore; its binding apparently prevents alpha-DTX (7054Da), but not ChTX (4300 Da), from blocking the pore. The effects of TsTX-K alphaon 125I-alpha-DTX binding and 86Rb efflux are mimicked by noxiustoxin, which ishomologous to TsTX-K alpha and ChTX. |
| Starting Page | 1475 |
| File Format | |
| ISSN | 10916490 |
| e-ISSN | 10916490 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Issue Number | 4 |
| Volume Number | 91 |
| Language | English |
| Publisher Date | 1994-02-15 |
| Access Restriction | Open |
| Subject Keyword | Research in Higher Education |
| Content Type | Text |
| Resource Type | Article |
| Subject | Multidisciplinary |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|