Biologically active proteins having increased in vivo and/or in vitro stability

Abstract

The present invention provides unstructured recombinant polymers (URPs) and proteins containing one or more of the URPs. The present invention also provides microproteins, toxins and other related proteinaceous entities, as well as genetic packages displaying these entities. The present invention also provides recombinant polypeptides including vectors encoding the subject proteinaceous entities, as well as host cells comprising the vectors. The subject compositions have a variety of utilities including a range of pharmaceutical applications.

1 .- 14 . (canceled) 
     
     
         15 . An unstructured recombinant polymer (URP) comprising at least 40 contiguous amino acids, wherein said URP is substantially incapable of non-specific binding to a serum protein, and wherein (a) the sum of glycine (G), aspartate (D), alanine (A), serine (S), threonine (T), glutamate (E) and proline (P) residues contained in the URP, constitutes more than about 80% of the total amino acids of the URP; and/or (b) at least 50% of the amino acids are devoid of secondary structure as determined by Chou-Fasman algorithm. 
     
     
         16 . An unstructured recombinant polymer (URP) comprising at least 40 contiguous amino acids, wherein said URP has an in vitro serum degradation half-life greater than about 24 hours, and wherein (a) the sum of glycine (G), aspartate (D), alanine (A), serine (S), threonine (T), glutamate (E) and proline (P) residues contained in the URP, constitutes more than about 80% of the total amino acids of the URP; and/or (b) at least 50% of the amino acids are devoid of secondary structure as determined by Chou-Fasman algorithm. 
     
     
         17 . The URP of claim  1  or  2 , wherein the URP comprises a non-natural amino acid sequence. 
     
     
         18 . The URP of claim  1  or  2 , wherein the URP is selected for incorporation into a heterologous protein, and wherein upon incorporation the URP into a heterologous protein, said heterologous protein exhibits a longer serum half-life and/or higher solubility as compared to the corresponding protein that is deficient in said URP. 
     
     
         19 . The URP of claim  1  or  2 , wherein upon incorporation of the URP into a heterologous protein, said heterologous protein exhibits a serum secretion half-life that is at least two times longer as compared to the corresponding protein that is deficient in said URP. 
     
     
         20 . The URP of claim  1  or  2 , wherein incorporation of the URP into a heterologous protein results in at least a 2-fold increase in apparent molecular weight of the protein as approximated by size exclusion chromatography. 
     
     
         21 . The URP of claim  1  or  2 , wherein the URP has a Tepitope score less than −4. 
     
     
         22 . The URP of claim  1  or  2 , wherein the amino acids are predominantly hydrophilic residues. 
     
     
         23 . The URP of claim  1  or  2 , wherein at least 50% of the amino acids of the URP are devoid of secondary structure as determined by Chou-Fasman algorithm. 
     
     
         24 . The URP of claim  1  or  2 , wherein glycine residues contained in the URP constitute at least about 50% of the total amino acids of the URP. 
     
     
         25 . The URP of claim  1  or  2 , wherein any one type of the amino acids alone selected from the group consisting of glycine (G), aspartate (D), alanine (A), serine (S), threonine (T), glutamate (E) and proline (P) constitutes more than about 20% of the total amino acids of the URP.