Mutant protein and methods and materials for making and using it

The invention provides a mutant protein which has the same amino acid sequence as an unmutated C-reactive protein (CRP) subunit or an unmutated preCRP, except that at least one amino acid of the unmutated CRP subunit or unmutated preCRP has been deleted, at least one amino acid of the unmutated CRP subunit or unmutated preCRP has been replaced by another amino acid, at least one amino acid has been added to the unmutated CRP subunit or preCRP, or a combination of such changes has been made. The amino acid(s) added, deleted and/or replaced are chosen so that the mutant protein is less likely to form covalently cross-linked aggregates than the unmutated CRP subunit or unmutated preCRP. The mutant protein also exhibits at least one of the biological activities of modified-CRP. The invention also provides DNA molecules coding for the mutant proteins of the invention, vectors for expressing the mutant proteins, host cells which have been transformed so that they can express the mutant proteins, and a method of producing the mutant proteins of the invention comprising culturing the transformed host cells. Finally, the invention provides methods and materials for using the mutant proteins.