GFP:HIV-1 Protease Production and Packaging with a T4 Phage Expression-Packaging Processing System

Autor: Julienne M. Mullaney, Lindsay W. Black
Jazyk: angličtina
Rok vydání: 1998
Předmět:
Zdroj: BioTechniques, Vol 25, Iss 6, Pp 1008-1012 (1998)
Druh dokumentu: article
ISSN: 1940-9818
0736-6205
DOI: 10.2144/98256st03
Popis: A bacteriophage T4-derived protein expression, packaging and processing system was used to create recombinant phage that encode, produce and package a protein composed of human HIV-1 protease fused to green fluorescent protein (GFP). The fusion protein is targeted within the phage capsid by an N-terminal capsid targeting sequence (CTS), which is cleaved through proteolysis by the viral scaffold protease P21. The fusion protein is designated CTS▾ GFP:PR. The ▾ symbol indicates the linkage peptide sequence leu(ile)-N-glu that is cleaved by the T4 head morphogenetic proteinase gp21 during head maturation. The fusion protein is fluorescent and has protease activity as detected by the appearance of the expected substrate cleavage product on a Western blot. CTS▾ GFP:PR packaging occurs at about 200 molecules per phage particle. The CTS▾ GFP:PR fusion protein, when protected within the phage capsid, has been maintained stably for over 16 months at 4°C. Production and storage of fusion protein within the phage circumvents problems of toxicity and solubility encountered with E. coli expression systems. Because recombinant phage inhibit host proteolytic enzymes, foreign proteins are stabilized. This phage system packages and processes the fusion protein by means of the CTS. Proteins can be purified from the phage to give high yields of soluble, proteolytically processed protein. The T4 phage packaging system provides a novel means of identification, purification and long-term storage of toxic proteins whose folding and DNA-directed activities can be studied readily in vivo.
Databáze: Directory of Open Access Journals
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