Engineering S-protein fragments of bovine ribonuclease A for targeted drug delivery.
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.
Backer
Marina V
MV
SibTech Inc., 705 North Mountain Road, Newington, CT 06111, USA. mbacker@sibtech.com
Gaynutdinov
Timur I
TI
Aloise
Renee
R
Przekop
Kristen
K
Backer
Joseph M
JM
D000818:Animals; D002417:Cattle; D016503:Drug Delivery Systems / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods*; D017510:Protein Folding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012259:Ribonuclease, Pancreatic / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D012259:Ribonuclease, Pancreatic