Peptide ligands for capture of host cell proteins

A composition for use in a method of removing one or more host cell proteins from a mixture comprising the one or more host cell proteins and one or more target biomolecules, wherein the composition comprises one or more peptides each independently comprising a sequence selected from the group consisting of GSRYRY (SEQ ID NO:

• 1), RYYYAI (SEQ ID NO:
• 2), AAHIYY (SEQ ID NO:
• 3), IYRIGR (SEQ ID NO:
• 4), HSKIYK (SEQ ID NO:
• 5), ADRYGH (SEQ ID NO:
• 6), DRIYYY (SEQ ID NO:
• 7), DKQRII (SEQ ID NO:
• 8), RYYDYG (SEQ ID NO:
• 9), YRIDRY (SEQ ID NO:
• 10), HYAI (SEQ ID NO:
• 11), FRYY (SEQ ID NO:
• 12), HRRY (SEQ ID NO:
• 13), RYFF (SEQ ID NO:
• 14), DKSI (SEQ ID NO:
• 15), DRNI (SEQ ID NO:
• 16), HYFD (SEQ ID NO:
• 17), and YRFD (SEQ ID NO:
• 18);
• and
• wherein each peptide in the composition has a greater binding affinity for the one or more host cell proteins than for the one or more target biomolecules.