Serum albumin binding proteins

Abstract

The present invention relates to amino acid sequences that are capable of binding to serum albumin; to proteins and polypeptides comprising or essentially consisting of such amino acid sequences; to nucleic acids that encode such amino acid sequences, proteins or polypeptides; to compositions, and in particular pharmaceutical compositions, that comprise such amino acid sequences, proteins and polypeptides; and to uses of such amino acid sequences, proteins and polypeptides.

1 . Polypeptide, protein, construct, compound or other chemical entity that comprises or essentially consists of the amino acid sequence Alb-23 (SEQ ID NO:1) or a variant of Alb-23 which is capable of specifically binding to human serum albumin and in which the amino acid residue at position 5 is L, the amino acid residue at position 16 is G, the amino acid residues at positions 44 and 45 are GP, the amino acid residues at positions 74 to 76 are SKN, and the amino acid residue at position 83 is R, and one or more (such as one or two) other immunoglobulin single variable domains. 
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . Polypeptide, protein, construct, compound or other chemical entity according to  claim 1 , in which said one or more (such as one or two) other immunoglobulin single variable domains are one or more (such as one or two) therapeutic immunoglobulin single variable domains. 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . Polypeptide, protein construct, compound or other chemical entity according to  claim 1 , in which said one or more (such as one or two other immunoglobulin single variable domains are immunoglobulin single variable domains that comprise at least two disulphide bridges. 
     
     
         8 . Polypeptide, protein construct, compound or other chemical entity according to  claim 1 , in which at least one (and up to all) of the other immunoglobulin single variable domains is a Nanobody of VHH Class I. 
     
     
         9 .- 13 . (canceled)