Patent ID: 8277820

Claim:
An isolated variant of an Erysipelothrix rhusiopathiae surface protective antigen SpaA protein or of a shortened form thereof (known as ΔSpaA protein), wherein the SpaA protein comprises the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:7, and the ΔSpaA protein is a shortened form of the SpaA protein in which the C-terminal 206 amino acid residues of the SpaA protein comprising the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:7 are deleted, wherein said variant is immunogenic, and expressed in E. coli as inclusion bodies, and is selected from the group consisting of: (1) the SpaA protein comprising the amino acid sequence encoded by SEQ ID NO:7 with the amino acid substitution of arginine to glycine at the residue corresponding to residue position 531 of SEQ ID NO:2; (2) the SpaA protein comprising the amino acid sequence encoded by SEQ ID NO:7 with the amino acid substitution of histidine to glutamine at the residue corresponding to residue position 214 of SEQ ID NO:2 and the amino acid substitution of methionine to threonine at the residue corresponding to residue position 253 of SEQ ID NO:2; (3) the ΔSpaA protein with the amino acid substitution of histidine to glutamine at the residue corresponding to residue position 214 of SEQ ID NO:2 and the amino acid substitution of methionine to threonine at the residue corresponding to residue position 253 of SEQ ID NO:2; (4) the ΔSpaA protein with the amino acid substitution of glutamic acid to glycine at the residue corresponding to residue position 69 of SEQ ID NO:2, the amino acid substitution of glutamic acid to glycine at the residue corresponding to residue position 154 of SEQ ID NO:2, and the amino acid substitution of isoleucine to threonine at the residue corresponding to residue position 203 of SEQ ID NO:2; and (5) the ΔSpaA protein with the amino acid substitution of aspartic acid to glycine at the residue corresponding to residue position 278 of SEQ ID NO:2.