In addition, electron transfer rates for stellacyanin are faster than for other type I copper proteins suggesting stellacyanin is more solvent accessible at the active site. The exact function of stellacyanin is unknown. However, given the fact that type I copper proteins are involved in electron transfer and stellacyanin appears to be associated with the plant cell wall, it is suggested that it is involved in oxidative cross-linking reactions to build polymeric material making up the cell wall.
The increased rate of electron transfer for stellacyanin compared to other type I copper proteins implies greater accessibility at its active site. The exact role of stellacyanin remains unclear, but the connection between type I copper proteins and electron transfer, combined with stellacyanin's association with plant cell walls, suggests that it may be involved in cross-linking reactions to form polymeric materials within the cell wall.