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. © 2012 Elsevier Inc.
Structural and enzymatic properties of an in vivo proteolytic form of PD-S2, type 1 ribosome-inactivating protein from seeds of Phytolacca dioica L
DI MARO, Antimo;
2012
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. © 2012 Elsevier Inc.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
