Immobilized palladium(II) ion affinity chromatography for recovery of recombinant proteins with peptide tags containing histidine and cysteine

Abstract

Fusion of peptide-based tags to recombinant proteins is currently one of the most used tools for protein production. Also, immobilized metal ion affinity chromatography (IMAC) has a huge application in protein purification, especially in research labs. The combination of expression systems of recombinant tagged proteins with this robust chromatographic system has become an efficient and rapid tool to produce milligram-range amounts of proteins. IMAC-Ni(II) columns have become the natural partners of 6xHis-tagged proteins. The Ni(II) ion is considered as the best compromise of selectivity and affinity for purification of a recombinant His-tagged protein. The palladium(II) ion is also able to bind to side chains of amino acids and form ternary complexes with iminodiacetic acid and free amino acids and other sulfur-containing molecules. In this work, we evaluated two different cysteine- and histidine-containing six amino acid tags linked to the N-terminal group of green fluorescent protein (GFP) and studied the adsorption and elution conditions using novel eluents. Both cysteine-containing tagged GFPs were able to bind to IMAC-Pd(II) matrices and eluted successfully using a low concentration of thiourea solution. The IMAC-Ni(II) system reaches less than 20% recovery of the cysteine-containing tagged GFP from a crude homogenate of recombinant Escherichia coli, meanwhile the IMAC-Pd(II) yields a recovery of 45% with a purification factor of 13.

Cancer-derived exosomes loaded with ultrathin palladium nanosheets for targeted bioorthogonal catalysis

“…This artefact may be consequence of the Pd-Exo A549 lysing step during sample processing and attributed to coordination with free Pd species. 61 The low impact of the process to the protein composition of the exosomes is further supported by the XPS data (Suppl. Fig.…”

Protein Particles Decorated with Pd Nanoparticles for the Catalytic Reduction of p-Nitrophenol to p-Aminophenol

“…In addition, as a few PdNPs were synthesized in (w/o H 6 ) HBVcAg PPs, it is possible to control the number of PdNPs by changing the number of H 6 in PPs . It is well known that a Pd ion can bind to two histidines. ,, Thus, we can expect that the size of PdNPs on PPs is different depending on the length of histag (i.e., H 8 , H 12 , etc.) owing to the difference of the metal ion binding efficiency and the number of metal ions at the initial nucleation stage. , …”

“…48 It is well known that a Pd ion can bind to two histidines. 47,49,50 Thus, we can expect that the size of PdNPs on PPs is different depending on the length of histag (i.e., H 8 , H 12 , etc.) owing to the difference of the metal ion binding efficiency and the number of metal ions at the initial nucleation stage.…”