| Autor: |
Kini SG; School of Biological Sciences, Nanyang Technological University , Singapore 637551., Nguyen PQ; School of Biological Sciences, Nanyang Technological University , Singapore 637551., Weissbach S; Institut für Chemie, Universität zu Lübeck , Lübeck, Germany., Mallagaray A; Institut für Chemie, Universität zu Lübeck , Lübeck, Germany., Shin J; School of Biological Sciences, Nanyang Technological University , Singapore 637551., Yoon HS; School of Biological Sciences, Nanyang Technological University , Singapore 637551., Tam JP; School of Biological Sciences, Nanyang Technological University , Singapore 637551. |
| Jazyk: |
angličtina |
| Zdroj: |
Biochemistry [Biochemistry] 2015 Nov 03; Vol. 54 (43), pp. 6639-49. Date of Electronic Publication: 2015 Oct 21. |
| DOI: |
10.1021/acs.biochem.5b00872 |
| Abstrakt: |
Hevein-like peptides make up a family of cysteine-rich peptides (CRPs) and play a role in plants in their defense against insects and fungal pathogens. In this study, we report the isolation and characterization of six hevein-like peptides, aSG1-G3 and aSR1-R3, collectively named altides from green and red varieties of Alternanthera sessilis, a perennial herb belonging to the Amaranthaceae family. Proteomic analysis of altides revealed they contain six cysteines (6C), seven glycines, four prolines, and a conserved chitin-binding domain (SXYGY/SXFGY). Thus far, only four 6C-hevein-like peptides have been isolated and characterized; hence, our study expands the existing library of these peptides. Nuclear magnetic resonance (NMR) study of altides showed its three disulfide bonds were arranged in a cystine knot motif. As a consequence of this disulfide arrangement, they are stable against thermal and enzymatic degradation. Gene cloning studies revealed altides contain a three-domain precursor with an endoplasmic reticulum signal peptide followed by a mature CRP domain and a short C-terminal tail. This indicates that the biosynthesis of altides is through the secretory pathway. (1)H NMR titration experiments showed that the 29-30-amino acid altides bind to chitin oligomers with dissociation constants in the micromolar range. Aromatic residues in the chitin-binding domain of altides were involved in the binding interaction. To the best of our knowledge, aSR1 is the smallest hevein-like peptide with a dissociation constant toward chitotriose comparable to those of hevein and other hevein-like peptides. Together, our study expands the existing library of 6C-hevein-like peptides and provides insights into their structure, biosynthesis, and interaction with chitin oligosaccharides. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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