Patent ID: 9115182
Filing Date: 2015-08-25
Classification: C07K,Y10T

Abstract:
1. A method comprising: a) providing a host cell comprising an expressible genetic construct encoding an insoluble fusion peptide comprising at least one first portion and at least one second portion, wherein said first portion comprises a multi-functional solubility tag (MST) and said second portion comprises a peptide of interest (POI); wherein the multi-functional solubility tag (MST) has the general formula of: wherein SEQ ID NO: 1 is Xaa1-Gln-[Xaa2] p -[Phe-Xaa3-Xaa4-Xaa5] s -Phe-Xaa6-[Xaa7] q -[Gin] r ; and SEQ ID NO: 2 is Xaa1-Gln-Xaa8-[Xaa4-Xaa8] s -Phe-[Glu-Gln-Gln] r ; wherein Xaa1=Gln or His; Xaa2=Gln, Arg, His, or Lys; Xaa3=Gln, His, Lys, Arg, or Glu; Xaa4=Trp or Phe; Xaa5=Gln, His, Lys, Arg or Glu; Xaa6=Glu, Gln, or Arg; Xaa7=Gln or Lys; Xaa8=Asp, Glu, Gln, His, Lys, or Arg; p, q, and r are independently 0 or 1; s is an integer ranging from 1 to 5; n is an integer ranging from 2 to 10; m=n or n-1; and Spacer=a peptide linker ranging from 3 to 60 amino acids in length; wherein said spacer comprises at least one cross-linkable cysteine residue; b) growing the microbial host cell whereby the insoluble fusion peptide is produced within the host cell in the form of at least one inclusion body; c) recovering the insoluble fusion peptide from the microbial host cell; d) subjecting the recovered insoluble fusion peptide of (c) to aqueous reducing conditions having a pH of at least 10 for a period of time to solubilize the insoluble fusion peptide and reduce cross-linkable cysteine residues; whereby an aqueous solution comprising a population of reduced fusion peptides is produced; e) contacting the aqueous solution comprising the population of reduced fusion peptides of (d) with a first target material whereby a mixture is formed; f) altering the pH of the mixture of (e) whereby the population of reduced fusion peptides non-covalently binds with the first target material forming fusion peptide-first target material complexes; wherein the binding between the fusion peptides and the first target material is dependent upon, or enhanced by, the presence of the multi-functional solubility tag; g) subjecting the fusion peptide-first target material complexes of (f) to oxidizing conditions whereby the cysteine residues cross-link; and h) optionally recovering the product of step (g).