OVA Peptide(257-264) acetate salt is a Class I (Kb)-restricted epitope of OVA. This octamer peptide is presented by Class I MHC molecule H-2Kb derived from ovalbumin.

OVA Peptide(257-264) epitope processing varies based on its protein context, affecting its TAP transporter dependency for MHC class I presentation. TAP1-I- and C57BL/6 macrophages may handle Crl-OVA and full-length OVA differently within various cellular compartments. The epitope within MBPCrl-OVA or Crl-OVA fusion proteins shows minimal TAP dependence, whereas when part of full-length ovalbumin, it largely relies on the TAP transporter, regardless of whether the recombinant OVA is expressed in bacteria or coupled to polystyrene beads.