Variant aim

Abstract

The present invention relates to the provision of a recombinant AIM that maintains functions, does not multimerize, and is not inactivated by IgM (e.g., a protein containing an amino acid sequence wherein cysteine at amino acid number 168 of the amino acid sequence shown in SEQ ID NO: 1 is substituted with another amino acid, and the like).

1 . A mutant human AIM comprising an amino acid sequence of any one of the following (1) to (5) and having an activity of wild-type human AIM
 (1) an amino acid sequence wherein cysteine at amino acid number 168 of the amino acid sequence shown in SEQ ID NO: 1 is substituted with another amino acid,   (2) an amino acid sequence wherein cysteine at amino acid number 277 of the amino acid sequence shown in SEQ ID NO: 1 is substituted with another amino acid,   (3) an amino acid sequence wherein cysteine at amino acid number 168 of the amino acid sequence shown in SEQ ID NO: 1 is substituted with another amino acid, and an amino acid sequence wherein cysteine at amino acid number 277 of the amino acid sequence shown in SEQ ID NO: 1 is substituted with another amino acid,   (4) an amino acid sequence substantially the same as the amino acid sequence of any one of (1) to (3), and cysteines present in the amino acid sequence of any one of (1) to (3) and the substituted another amino acid remain,   (5) an amino acid sequence further comprising deletion, addition, insertion or substitution of one to several amino acids or a combination thereof at a position other than cysteines present in the amino acid sequence of any one of (1) to (3) and the substituted another amino acid.   
     
     
         2 . The mutant human AIM according to  claim 1 , wherein said another amino acid is an amino acid selected from the group consisting of asparagine, glutamine, serine, and threonine. 
     
     
         3 . The mutant human AIM according to  claim 1 , wherein said another amino acid is serine. 
     
     
         4 . A mutant mouse AIM comprising an amino acid sequence of any one of the following (1) to (3) and having an activity of wild-type mouse AIM
 (1) an amino acid sequence wherein cysteine at amino acid number 168 of the amino acid sequence shown in SEQ ID NO: 2 is substituted with another amino acid,   (2) an amino acid sequence substantially the same as the amino acid sequence of (1), and cysteines present in the amino acid sequence of (1) and the substituted another amino acid remain,   (3) an amino acid sequence further comprising deletion, addition, insertion or substitution of one to several amino acids or a combination thereof at a position other than cysteines present in the amino acid sequence of (1) and the substituted another amino acid.   
     
     
         5 . The mutant mouse AIM according to  claim 4 , wherein said another amino acid is an amino acid selected from the group consisting of asparagine, glutamine, serine, and threonine. 
     
     
         6 . The mutant mouse AIM according to  claim 4 , wherein said another amino acid is serine. 
     
     
         7 . A nucleic acid comprising the base sequence of the following (1) or (2)
 (1) a base sequence encoding the mutant human AIM according to any one of  claims 1  to  3 ,   (2) a base sequence encoding the mutant mouse AIM according to any one of  claims 4  to  6 .   
     
     
         8 . An expression vector comprising the nucleic acid according to  claim 7 . 
     
     
         9 . A host cell comprising the expression vector according to  claim 8 . 
     
     
         10 . A method for producing a mutant human AIM or a mutant mouse AIM, comprising culturing the host cell according to  claim 9 . 
     
     
         11 . A pharmaceutical composition comprising a mutant AIM of the following (1) or (2)
 (1) the mutant human AIM according to any one of  claims 1  to  3 ,   (2) the mutant mouse AIM according to any one of  claims 4  to  6 .