Cardosin A is an RGD-containing aspartic proteinase from the stigmatic papillae ofCynara cardunculusL. A putative cardosin A-binding protein has previously been isolated from pollen suggesting its potential involve-ment in pollen–pistil interaction [Faro C, Ramalho-Santos M, Vieira M, Mendes A, Simo˜es I, Andrade R, Verissimo P, Lin X, Tang J & Pires E (1999) J Biol Chem274, 28724–28729].