Structural characterization and comparative modeling of PD-Ls 1-3, type 1 ribosome-inactivating proteins from summer leaves of Phytolacca dioica L.
Biochimie
; 91(3): 352-63, 2009 Mar.
Article
in En
| MEDLINE
| ID: mdl-19014994
ABSTRACT
The amino acid sequence and glycan structure of PD-L1, PD-L2 and PD-L3, type 1 ribosome-inactivating proteins isolated from Phytolacca dioica L. leaves, were determined using a combined approach based on peptide mapping, Edman degradation and ESI-Q-TOF MS in precursor ion discovery mode. The comparative analysis of the 261 amino acid residue sequences showed that PD-L1 and PD-L2 have identical primary structure, as it is the case of PD-L3 and PD-L4. Furthermore, the primary structure of PD-Ls 1-2 and PD-Ls 3-4 have 81.6% identity (85.1% similarity). The ESI-Q-TOF MS analysis confirmed that PD-Ls 1-3 were glycosylated at different sites. In particular, PD-L1 contained three glycidic chains with the well known paucidomannosidic structure (Man)(3) (GlcNAc)(2) (Fuc)(1) (Xyl)(1) linked to Asn10, Asn43 and Asn255. PD-L2 was glycosylated at Asn10 and Asn43, and PD-L3 was glycosylated only at Asn10. PD-L4 was confirmed to be not glycosylated. Despite an overall high structural similarity, the comparative modeling of PD-L1, PD-L2, PD-L3 and PD-L4 has shown potential influences of the glycidic chains on their adenine polynucleotide glycosylase activity on different substrates.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plant Proteins
/
Seasons
/
Plant Leaves
/
Phytolacca
/
Ribosome Inactivating Proteins
Language:
En
Journal:
Biochimie
Year:
2009
Document type:
Article
Affiliation country:
Italy
Publication country:
FR
/
FRANCE
/
FRANCIA
/
FRANÇA