Patent ID: 8110197

Claim:
A detoxified E. coli heat-labile enterotoxin, comprising a mutated subunit A containing only one mutated residue as compared to its wild-type counterpart, the mutated residue being K and located at the position corresponding to position 61 of SEQ ID NO:5; and E. coli heat-labile enterotoxin subunit B, wherein the detoxified E. coli heat-labile enterotoxin is in AB 5 format, and wherein detoxified E. coli heat-labile enterotoxin proteins purified from an E. coli expressing the mutated subunit A and E. coli heat-labile enterotoxin subunit B are in the AB 5 format and the B 5 format, the AB 5 /AB 5 +B 5 ratio being at least 1.3 fold greater than the AB 5 /AB 5 +B 5 ratio of detoxified E. coli heat-labile enterotoxin proteins purified from an E. coli expressing a mutated E. coli heat-labile enterotoxin subunit A having F at the position, corresponding to position 61 of SEQ ID NO:5 and E. coli heat-labile enterotoxin subunit B.