title: Application of reversible biotinylated label for directed immobilization of synthetic peptides and proteins: isolation of ligates from crude cell lysates.
abstract: Chaperonin 10 protein from Rattus norvegicus (Rat cpn 10) has been reported to bind chaperonin 60 from Escherichia coli (GroEL) in an ATP-dependent manner. Chemically synthesized Rat cpn10 was immobilized in a defined orientation to agarose-bound monomeric avidin using a reversible biotinylated affinity label (1), attached to the N alpha-terminal residue. The resulting affinity chromatographic matrix was then used to isolate binding proteins from a crude cell lysate. Following affinity separation the bound ligand and ligate was released by treatment with organic base. Rat cpn 10 was prepared using a highly effective synthetic protocol involving HBTU/HOBt activation and capping with N-(2-chlorobenzyloxycarbonyloxy) succinimide to terminate unreacted amino groups. The biotinylated Fmoc-based molecule (1) was introduced specifically onto the N alpha-terminal amino acid as the succinimidyl carbonate, before final cleavage and deprotection of side-chain protecting groups using a low-TFMSA/high-HF procedure. Crude biotinylated Rat cpn10 (Rat cpn10 + 1) was immobilized on monomeric avidin with a binding efficiency of approximately 75% and unlabelled truncated/capped impurities eluted off the column with buffer. The biotinylated Rat cpn10-avidin affinity matrix was then used to isolate GroEL from a crude cell lysate. The identity of the purified protein was confirmed by SDS-PAGE and binding to a specific anti-GroEL monoclonal antibody (MoAb). These results extend the applicability of the biotinylated label (1), providing a reversible non-covalent anchor for immobilization of peptide and protein ligands, thus simplifying isolation of ligates and enabling recovery of synthetic material under mild conditions.
authors.affiliation: Department of Chemistry, Italfarmaco Research Centre, Milan, Italy.
authors.forename: H L
authors.initials: HL
authors.lastname: Ball
authors.forename: P
authors.initials: P
authors.lastname: Mascagni
mesh_terms: D000818:Animals; D001710:Biotin / Q000737:chemistry*; D018835:Chaperonin 10 / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D018834:Chaperonin 60 / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D011485:Protein Binding; D051381:Rats
chemical_list: D018835:Chaperonin 10; D018834:Chaperonin 60; D010455:Peptides; D001710:Biotin