Sushi peptide multimer
Endotoxin, also known as lipopolysaccharides (LPS), is the major mediator of septic shock due to Gram-negative bacterial infection. Chemically synthesized S3 peptide, derived from Sushi3 domain of Factor C, which is the endotoxin-sensitive serine protease of the limulus coagulation cascade, binds and neutralizes LPS activity. Fluorescent tagged-S3 is shown to detect LPS-containing bacteria. For large-scale production of S3 and to mimic other pathogen-recognizing molecules, tandem multimers of the S3 gene were constructed and expressed in E. coli . Tetramer of S3 for example is shown to display an enhanced inhibitory effect on LPS-induced activities. An affinity matrix based on tetramer of S3 is also shown to be particularly efficient at removing LPS.
1. A polypeptide comprising more than one S3 peptides comprising the amino acid sequence set forth in SEQ ID No: 1, wherein at least two of the S3 peptides are separated by a linking sequence cleavable by a protease.
2. The polypeptide of claim 1 wherein the S3 peptides are in tandem repeat.
3. The polypeptide of claim 1 comprising 2 to 10 S3 peptides.
4. The polypeptide of claim 1 comprising two S3 peptides.
5. The polypeptide of claim 1 comprising three S3 peptides.
6. The polypeptide of claim 1 comprising four S3 peptides.
7. The polypeptide of claim 1 comprising eight S3 peptides.
8. A polypeptide comprising more than one S3 peptides comprising the amino acid sequence set forth in SEQ ID No: 1, wherein at least two of the S3 peptides are separated by a linking sequence cleavable by acid digestion.
9. The polypeptide of claim 8 wherein at least one of the linking sequences comprises Asp-Pro.
10. A polypeptide comprising the amino acid sequence set forth in SEQ ID NO:9, having a linking sequence cleavable by a protease.
11. The polypeptide of claim 1 wherein the more than one S3 peptide is tagged with a detectable label.
12. The polypeptide of claim 11 wherein the label is detectable by fluorescence.
13. The polypeptide of claim 1 immobilized on a solid medium.
14. The polypeptide of claim 11 immobilized on a solid medium.
15. The polypeptide of claim 14 wherein the solid medium is agarose.
16. A package comprising the polypeptide of claim 1 and instructions for its use in detecting LPS-containing bacteria in a sample.
17. A package comprising the polypeptide of claim 13 and instructions for its use for removing LPS or LPS-containing bacteria from a sample.