Alternative zinc binding peptides as potential tags for recombinant protein purification.

Efficient binding of peptides and proteins to metal-chelating resins is a cornerstone of modern biochemical purification. This study evaluates a novel heptapeptide sequence, acetyl-Aa-Aa-Gly-Pro-Aa-His-Cys, where Aa = His or Asp, Aa = Cys or Asp and Aa = Tyr or Gly for its capacity to bind zinc-chelating resin consisting of divalent zinc chelated by iminodiacetate coupled to 6 % cross-linked agarose beads. Comparisons were made against the widely utilized 7 × His tag using an internal standard method with ion mobility - mass spectrometry analyses and ultra-violet absorption analyses, which quantified the binding efficiency and selectivity of these peptides under pH 8 conditions and the elution from the zinc resin using pH 3.

Zn(II) Affinity and Structural Conformations of 2His-2Cys Zinc Finger-Like Motif Peptide Determined by Ion Mobility-Mass Spectrometry and PM6 Molecular Modeling.

This study focuses on investigating the conformational structure and zinc(II) affinity of a zinc finger-like motif (ZFM) peptide with the sequence acetyl-His-Cys-Gly-Pro-Gly-His-Cys, where bold highlights the potential zinc(II) binding sites. Zinc fingers are crucial protein motifs known for their high specificity and affinity for zinc ions. The ZFM peptide's sequence contains the 2His-2Cys zinc-binding sites similar to those in natural zinc finger proteins but without the hydrophobic core, making it a valuable model for studying zinc(II)-peptide interactions.