A C‐terminal proline is required for bioluminescence of the Ca2+‐binding photoprotein, aequorin

Abstract
The requirement for a proline residue at the C‐terminus of the Ca2+‐binding photoprotein, aequorin, was investigated by measuring luminescence activities of a series of C‐terminal deletion mutants, substitution mutants and an addition mutant. CD spectral measurements of apoaequorin with the C‐terminal proline deleted showed a small change in secondary structure. In all cases studied, the C‐terminal proline was required for bioluminescence activity.