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Stability and assembly in vitro of bacteriophage PP7 virus-like particles
BACKGROUND: The stability of a virus-like particle (VLP) is an important consideration for its use in nanobiotechnology. The icosahedral capsid of the RNA bacteriophage PP7 is cross-linked by disulfide bonds between coat protein dimers at its 5-fold and quasi-6-fold symmetry axes. This work determin...
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2007
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2211308/ https://www.ncbi.nlm.nih.gov/pubmed/18039380 http://dx.doi.org/10.1186/1477-3155-5-10 |
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author | Caldeira, Jerri C Peabody, David S |
author_facet | Caldeira, Jerri C Peabody, David S |
author_sort | Caldeira, Jerri C |
collection | PubMed |
description | BACKGROUND: The stability of a virus-like particle (VLP) is an important consideration for its use in nanobiotechnology. The icosahedral capsid of the RNA bacteriophage PP7 is cross-linked by disulfide bonds between coat protein dimers at its 5-fold and quasi-6-fold symmetry axes. This work determined the effects of these disulfides on the VLP's thermal stability. RESULTS: Measurements of the thermal denaturation behavior of PP7 VLPs in the presence and absence of a reducing agent show that disulfide cross-links substantially stabilize them against thermal denaturation. Although dimers in the capsid are linked to one another by disulfides, the two subunits of dimers themselves are held together only by non-covalent interactions. In an effort to confer even greater stability a new cross-link was introduced by genetically fusing two coat protein monomers, thus producing a "single-chain dimer" that assembles normally into a completely cross-linked VLP. However, subunit fusion failed to increase the thermal stability of the particles, even though it stabilized the isolated dimer. As a step toward gaining control of the internal composition of the capsid, conditions that promote the assembly of PP7 coat protein dimers into virus-like particles in vitro were established. CONCLUSION: The presence of inter-dimer disulfide bonds greatly stabilizes the PP7 virus-like particle against thermal denaturation. Covalently cross-linking the subunits of the dimers themselves by genetically fusing them through a dipeptide linker sequence, offers no further stabilization of the VLP, although it does stabilize the dimer. PP7 capsids readily assemble in vitro in a reaction that requires RNA. |
format | Text |
id | pubmed-2211308 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2007 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-22113082008-01-19 Stability and assembly in vitro of bacteriophage PP7 virus-like particles Caldeira, Jerri C Peabody, David S J Nanobiotechnology Research BACKGROUND: The stability of a virus-like particle (VLP) is an important consideration for its use in nanobiotechnology. The icosahedral capsid of the RNA bacteriophage PP7 is cross-linked by disulfide bonds between coat protein dimers at its 5-fold and quasi-6-fold symmetry axes. This work determined the effects of these disulfides on the VLP's thermal stability. RESULTS: Measurements of the thermal denaturation behavior of PP7 VLPs in the presence and absence of a reducing agent show that disulfide cross-links substantially stabilize them against thermal denaturation. Although dimers in the capsid are linked to one another by disulfides, the two subunits of dimers themselves are held together only by non-covalent interactions. In an effort to confer even greater stability a new cross-link was introduced by genetically fusing two coat protein monomers, thus producing a "single-chain dimer" that assembles normally into a completely cross-linked VLP. However, subunit fusion failed to increase the thermal stability of the particles, even though it stabilized the isolated dimer. As a step toward gaining control of the internal composition of the capsid, conditions that promote the assembly of PP7 coat protein dimers into virus-like particles in vitro were established. CONCLUSION: The presence of inter-dimer disulfide bonds greatly stabilizes the PP7 virus-like particle against thermal denaturation. Covalently cross-linking the subunits of the dimers themselves by genetically fusing them through a dipeptide linker sequence, offers no further stabilization of the VLP, although it does stabilize the dimer. PP7 capsids readily assemble in vitro in a reaction that requires RNA. BioMed Central 2007-11-26 /pmc/articles/PMC2211308/ /pubmed/18039380 http://dx.doi.org/10.1186/1477-3155-5-10 Text en Copyright © 2007 Caldeira and Peabody; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Caldeira, Jerri C Peabody, David S Stability and assembly in vitro of bacteriophage PP7 virus-like particles |
title | Stability and assembly in vitro of bacteriophage PP7 virus-like particles |
title_full | Stability and assembly in vitro of bacteriophage PP7 virus-like particles |
title_fullStr | Stability and assembly in vitro of bacteriophage PP7 virus-like particles |
title_full_unstemmed | Stability and assembly in vitro of bacteriophage PP7 virus-like particles |
title_short | Stability and assembly in vitro of bacteriophage PP7 virus-like particles |
title_sort | stability and assembly in vitro of bacteriophage pp7 virus-like particles |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2211308/ https://www.ncbi.nlm.nih.gov/pubmed/18039380 http://dx.doi.org/10.1186/1477-3155-5-10 |
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