title: Structural and enzymatic properties of an in vivo proteolytic form of PD-S2, type 1 ribosome-inactivating protein from seeds of Phytolacca dioica L.
abstract: PD-S2, type 1 ribosome-inactivating protein from Phytolacca dioica L. seeds, is an N-β-glycosidase likely involved in plant defence. In this work, we purified and characterized an in vivo proteolytic form of PD-S2, named cutPD-S2. Spectroscopic characterization of cutPD-S2 showed that the proteolytic cleavage between Asn195 and Arg196 does not alter the protein fold, but significantly affects its thermal stability. Most importantly, the proteolytic cleavage induces a 370-fold decrease of PD-S2 capacity of inhibiting in vitro protein biosynthesis. Our data catch the turning point from a typical role of PD-S2 as a defence protein to that of supplier of essential amino acids during seedling development.
authors.affiliation: Dipartimento di Scienze della Vita, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta, Italy. antimo.dimaro@unina2.it
authors.forename: Antimo
authors.initials: A
authors.lastname: Di Maro
authors.forename: Rita
authors.initials: R
authors.lastname: Berisio
authors.forename: Alessia
authors.initials: A
authors.lastname: Ruggiero
authors.forename: Rachele
authors.initials: R
authors.lastname: Tamburino
authors.forename: Valeria
authors.initials: V
authors.lastname: Severino
authors.forename: Enza
authors.initials: E
authors.lastname: Zacchia
authors.forename: Augusto
authors.initials: A
authors.lastname: Parente
mesh_terms: D000601:Amino Acids, Essential / Q000378:metabolism*; D018525:Germination; D029603:Phytolacca / Q000254:growth & development / Q000378:metabolism*; D014176:Protein Biosynthesis; D011487:Protein Conformation; D017510:Protein Folding; D055550:Protein Stability; D059748:Proteolysis; D054789:Ribosome Inactivating Proteins, Type 1 / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D012270:Ribosomes / Q000378:metabolism; D012639:Seeds / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000601:Amino Acids, Essential; D054789:Ribosome Inactivating Proteins, Type 1; C105087:PD-S2 protein, Phytolacca dioica