Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) .... from spinach Rubiscoby using a model peptide and partially purified protein. ... This might be the case for most plant-derived peptide sequences acting on animal receptors. ... In C3 plants, Rubisco is located in the stroma of all chloroplasts.