| 摘要 |
<p>A soluble polypeptide has an IgE-binding functionality corresponding to that of the α-chain of the mast-cell Fc-ε-R1 IgE receptor protein, and enhanced binding to the Fc portion of IgE, and comprises substantially the sequence and conformation of at least one and preferably both of the two C2-type immunoglobulin-like domains of the α-chain of the Fc-ε-R1 IgE receptor protein, substantially lacks a sequence corresponding to the transmembrane segment of said receptor protein, and has a mutation relative to a natural sequence of said receptor protein, especially for example (a) lys117 to large hydrophobic residue such as phe, tyr or trp; (b) glu132 to a large hydrophobic residue such as tyr; (c) lys154 to a large hydrophobic residue such as phe, leu, or tyr; (d) gly124 to a positively charged residue such as lysine or arginine; (e) lys128 to a negatively charged residue such as glutamate; (f) gln157 to a negatively charged residue such as glutamate or aspartate; (g) leu158 to a negatively charged residue such as glutamate or aspartate; (h) asp159 to a positively charged residue such as lysine or arginine. Also provided are corresponding polynucleotides and host cells and methods and pharmaceutical compositions for use in reducing excessive IgE action, e.g. allergic reaction.</p> |
