I C , an endogenous cytoplasmic inhibitor of vacuolar carboxypeptidase Y in the yeast Saccharomyces cerevisiae, is classified as a member of the phos-phatidylethanolamine-binding protein family. The binding of I C to phos-pholipid membranes was first analyzed using a liposome-binding assay and by surface plasmon resonance measurements, which revealed that the affin-