Engineering S-protein fragments of bovine ribonuclease A for targeted drug delivery

Protein Expr Purif. 2002 Dec;26(3):455-61. doi: 10.1016/s1046-5928(02)00546-6.

Abstract

High affinity interaction between S-protein and S-peptide fragments of bovine pancreatic RNase A has been recently used for construction of molecular vehicles for targeted drug delivery. The vehicle is assembled as a complex of drug carrier conjugated S-protein with S-peptide-tagged targeting protein. To avoid random chemical crosslinking of drug carriers to S-protein, we constructed a mutant 16-124aa fragment of RNase A in which 122ala is replaced with a cysteine residue. The mutant and the corresponding wild type fragments expressed in Escherichia coli are refolded into functional conformations only in the presence of S-peptide. After the removal of S-peptide, both fragments retain the ability to bind S-peptide and S-peptide-tagged proteins. The 122cys residue in the mutant fragment is available for site-specific conjugation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cattle
  • Drug Delivery Systems / methods*
  • Escherichia coli / genetics
  • Mutation
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics*
  • Peptide Fragments / metabolism*
  • Protein Engineering / methods*
  • Protein Folding
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Ribonuclease, Pancreatic / chemistry
  • Ribonuclease, Pancreatic / genetics*
  • Ribonuclease, Pancreatic / metabolism*

Substances

  • Peptide Fragments
  • Recombinant Fusion Proteins
  • Ribonuclease, Pancreatic