Martinez, ManuelDíaz Mendoza, María MercedesCarrillo, LauraDiaz, Isabel2024-01-222024-01-222007Martinez, Manuel, et al. «Carboxy Terminal Extended Phytocystatins Are Bifunctional Inhibitors of Papain and Legumain Cysteine Proteinases». FEBS Letters, vol. 581, n.o 16, junio de 2007, pp. 2914-18. https://doi.org/10.1016/j.febslet.2007.05.042.0014-579310.1016/j.febslet.2007.05.042https://hdl.handle.net/20.500.14352/94326The financial support from the Ministerio de Educación y Ciencia (BFU2005-00603) and from the Universidad Politécnica de Madrid (AL07-PID-008) is gratefully acknowledged.Plant legumains are cysteine proteinases putatively involved in processing endogenous proteins. Phytocystatins (PhyCys) have been described as plant inhibitors of papain-like cysteine proteinases. Some PhyCys contain a carboxy terminal extension with an amino acid motif (SNSL) similar to that involved in the inhibition of legumain-like proteins by human cystatins. The role of these carboxy terminal extended PhyCys as inhibitors of legumain-like cysteine proteinases is here shown by in vitro inhibition of human legumain and legumain-like activities from barley extracts. Moreover, site-directed mutagenesis has demonstrated that the asparagine of the SNSL motif is essential in this inhibition. We prove for first time the existence of legumain inhibitors in plants.engjournal article1873-3468https://doi.org/10.1016/j.febslet.2007.05.042open access577.112PhyCysPhytocystatinsBarleyCystatinCysteine proteinase inhibitorLegumainPapainBiotecnología2306 Química Orgánica