Abstract: The present application is directed to a peptides comprising an a-helix forming-amino acid sequence that binds a heat shock protein. Also included is a polypeptide comprising (a) a first peptide portion that comprises an ?-helix-forming amino acid sequence that binds a heat shock protein; and (b) at least one second peptide portion comprising an antigenic amino acid sequence and/or an a-helix-stabilizing amino acid sequence that increases the interaction of the first peptide portion with the heat shock protein. The present application also includes compositions comprising the peptides and/or polypeptides of present application and uses of the peptides and/or polypeptides of the present application for fractionating substances relevant for discovery, research or clinical analysis from a biological sample and as therapeutics.