Provided is a technology related to a horseshoe crab factor B variant, and also provided is means for performing endotoxin measurement with high sensitivity. A polypeptide having an amino acid sequence in which the amino acid residue at the 193-position in an amino acid sequence of a polypeptide of horseshoe crab factor B is substituted with a cysteine (Cys) residue, is produced. Endotoxin measurement can be carried out with high sensitivity by configuring a Limulus reagent by combining this polypeptide with horseshoe crab factor C.

Provided is a technology related to a horseshoe crab factor B variant, and also provided is means for performing endotoxin measurement with high sensitivity. A polypeptide having an amino acid sequence in which the amino acid residue at the 193-position in an amino acid sequence of a polypeptide of horseshoe crab factor B is substituted with a cysteine (Cys) residue, is produced. Endotoxin measurement can be carried out with high sensitivity by configuring a Limulus reagent by combining this polypeptide with horseshoe crab factor C.

The invention relates generally to hybrid amebocyte lysate compositions (including both native and recombinant components) and their use in detecting and/or quantifying endotoxin in a sample.

Provided is a technology related to a horseshoe crab factor B variant, and also provided is means for performing endotoxin measurement with high sensitivity. A polypeptide having an amino acid sequence in which the amino acid residue at the 193-position in an amino acid sequence of a polypeptide of horseshoe crab factor B is substituted with a cysteine (Cys) residue, is produced. Endotoxin measurement can be carried out with high sensitivity by configuring a Limulus reagent by combining this polypeptide with horseshoe crab factor C.

The subject of this invention is point mutants of human proteins constituting the complement system's C3 and C5 convertases, where the mutation are as follows: For the factor B: —D279G, F286L, K323E, Y363A; D279G_F286L_K323E_Y363A—quadruple mutant; For the C2 protein: —C261A, Q.263G, Y347A, L348A; T442Q, double mutants C261A_Q263G and Y347A_Q263G, triple mutant Y347A_Q263G_T442Q The subject of this invention is the method of enhancing the activity of the anti-cancer antibodies, which includes the addition of mutants defined above. The subject of this invention is the pharmaceutical composition, which includes the therapeutically effective number of mutants defined above. The subject of this invention is the use of mutants defined above to enhance the cytotoxic activity of anti-cancer antibodies in therapy and in the treatment of neoplastic diseases.

The subject of this invention is point mutants of human proteins constituting the complement system's C3 and C5 convertases, where the mutation are as follows: For the factor B:—D279G, F286L, K323E, Y363A; D279G_F286L_K323E_Y363A-quadruple mutant; For the C2 protein:—C261A, Q.263G, Y347A, L348A; T442Q, double mutants C261A_Q263G and Y347A_Q263G, triple mutant Y347A_Q263G_T442Q The subject of this invention is the method of enhancing the activity of the anti-cancer antibodies, which includes the addition of mutants defined above. The subject of this invention is the pharmaceutical composition, which includes the therapeutically effective number of mutants defined above. The subject of this invention is the use of mutants defined above to enhance the cytotoxic activity of anti-cancer antibodies in therapy and in the treatment of neoplastic diseases.

An object of the present invention is to provide a method for enhancing a sensitivity of a current endotoxin measuring reagent employing a recombinant protein to the endotoxin of Helicobacter pylori. The present invention provides a method for enhancing the sensitivity of an endotoxin measuring reagent to the endotoxin of Helicobacter pylori, the endotoxin measuring reagent containing a recombinant protein of horseshoe crab factor C, the method including increasing a content of the recombinant protein of factor C at the time of endotoxin measurement to an amount that is sufficient for enhancing the sensitivity.

The invention relates generally to hybrid amebocyte lysate compositions (including both native and recombinant components) and their use in detecting and/or quantifying endotoxin in a sample.

The invention relates generally to hybrid amebocyte lysate compositions (including both native and recombinant components) and their use in detecting and/or quantifying endotoxin in a sample.

Provided is a technology related to a horseshoe crab factor B variant, and also provided is means for performing endotoxin measurement with high sensitivity. A polypeptide having an amino acid sequence in which the amino acid residue at the 193-position in an amino acid sequence of a polypeptide of horseshoe crab factor B is substituted with a cysteine (Cys) residue, is produced. Endotoxin measurement can be carried out with high sensitivity by combining this polypeptide with horseshoe crab factor C, as a Limulus reagent.