📄 Dissection of SARS coronavirus spike protein into discrete folded fragments

The spike protein of the severe acute respiratory syndrome coronavirus (SARS-CoV) mediates cell fusion by binding to target cell surface receptors. This paper reports a simple method for dissecting the viral protein and for searching for foldable fragments in a random but systematic manner. The method involves digestion by DNase I to generate a pool of short DNA segments, followed by an additional step of reassembly of these segments to produce a library of DNA fragments with random ends but controllable lengths. To rapidly screen for discrete folded polypeptide fragments, the reassembled gene fragments were further cloned into a vector as N-terminal fusions to a folding reporter gene which was a variant of green fluorescent protein. Two foldable fragments were identified for the SARS-CoV spike protein, which coincide with various anti-SARS peptides derived from the hepated repeat (HR) region 2 of the spike protein. The method should be applicable to other viral proteins to isolate antigen or vaccine candidates, thus providing an alternative to the full-length proteins (subunits) or linear short peptides.

keywords 🔗 severe acute (1373) 🔗 syndrome coronavirus (1074) 🔗 green fluorescent (28) 🔗 spike protein (353) 🔗 cell surface (110) 🔗 viral proteins (89) 🔗 respiratory syndrome (2004) 🔗 acute respiratory (1734)

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