Enhancing the proteolytic maturation of human immunodeficiency virus type 1 envelope glycoproteins
| Autor: | James M. Binley, Shawn E. Kuhmann, Charmagne Cayanan, Aditi Master, Rogier W. Sanders, Linnea Schiffner, John P. Moore, Shiu Lok Hu, Dennis R. Burton, Cheryl Wiley, William C. Olson, Bruce M. Travis |
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| Přispěvatelé: | Medical Microbiology and Infection Prevention |
| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: |
Proteases
viruses Immunology Mutant HIV Envelope Protein gp120 Biology V3 loop Cleavage (embryo) Microbiology HIV Envelope Protein gp160 law.invention law Virology Endopeptidases Vaccines and Antiviral Agents Humans Subtilisins Protein Precursors Furin chemistry.chemical_classification Gene Products env virus diseases Molecular biology HIV Envelope Protein gp41 Recombinant Proteins Transmembrane domain chemistry Insect Science HIV-1 biology.protein Recombinant DNA Glycoprotein HeLa Cells |
| Zdroj: | Journal of virology, 76(6), 2606-2616. American Society for Microbiology |
| ISSN: | 0022-538X |
| DOI: | 10.1128/jvi.76.6.2606-2616.2002 |
| Popis: | In virus-infected cells, the envelope glycoprotein (Env) precursor, gp160, of human immunodeficiency virus type 1 is cleaved by cellular proteases into a fusion-competent gp120-gp41 heterodimer in which the two subunits are noncovalently associated. However, cleavage can be inefficient when recombinant Env is expressed at high levels, either as a full-length gp160 or as a soluble gp140 truncated immediately N-terminal to the transmembrane domain. We have explored several methods for obtaining fully cleaved Env for use as a vaccine antigen. We tested whether purified Env could be enzymatically digested with purified protease in vitro. Plasmin efficiently cleaved the Env precursor but also cut at a second site in gp120, most probably the V3 loop. In contrast, a soluble form of furin was specific for the gp120-gp41 cleavage site but cleaved inefficiently. Coexpression of Env with the full-length or soluble form of furin enhanced Env cleavage but also reduced Env expression. When the Env cleavage site (REKR) was mutated in order to see if its use by cellular proteases could be enhanced, several mutants were found to be processed more efficiently than the wild-type protein. The optimal cleavage site sequences were RRRRRR, RRRRKR, and RRRKKR. These mutations did not significantly alter the capacity of the Env protein to mediate fusion, so they have not radically perturbed Env structure. Furthermore, unlike that of wild-type Env, expression of the cleavage site mutants was not significantly reduced by furin coexpression. Coexpression of Env cleavage site mutants and furin is therefore a useful method for obtaining high-level expression of processed Env. |
| Databáze: | OpenAIRE |
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