Back to Search
Start Over
Allotides: Proline-Rich Cystine Knot α-Amylase Inhibitors from Allamanda cathartica.
- Source :
-
Journal of natural products [J Nat Prod] 2015 Apr 24; Vol. 78 (4), pp. 695-704. Date of Electronic Publication: 2015 Apr 02. - Publication Year :
- 2015
-
Abstract
- Cystine knot α-amylase inhibitors belong to a knottin family of peptidyl inhibitors of 30-32 residues and contain two to four prolines. Thus far, only four members of the group of cystine knot α-amylase inhibitors have been characterized. Herein, the discovery and characterization of five cystine knot α-amylase inhibitors, allotides C1-C5 (Ac1-Ac5) (1-5), from the medicinal plant Allamanda cathartica are reported using both proteomic and genomic methods. Proteomic analysis showed that 1-5 are 30 amino acids in length with three or four proline residues. NMR determination of 4 revealed that it has two cis- and one trans-proline residues and adopts two equally populated conformations in solution. Determination of disulfide connectivity of 2 by differential S-reduction and S-alkylation provided clues of its unfolding process. Genomic analysis showed that allotide precursors contain a three-domain arrangement commonly found in plant cystine knot peptides with conserved residues flanking the processing sites of the mature allotide domain. This work expands the number of known cystine knot α-amylase inhibitors and furthers the understanding of both the structural and biological diversity of this type of knottin family.
- Subjects :
- Amino Acid Sequence
Cystine-Knot Miniproteins chemistry
Disulfides chemistry
Molecular Structure
Nuclear Magnetic Resonance, Biomolecular
Protein Conformation
Protein Structure, Tertiary
Proteomics
Singapore
Apocynaceae chemistry
Cystine chemistry
Cystine-Knot Miniproteins isolation & purification
Cystine-Knot Miniproteins pharmacology
Plants, Medicinal chemistry
Proline chemistry
alpha-Amylases antagonists & inhibitors
Subjects
Details
- Language :
- English
- ISSN :
- 1520-6025
- Volume :
- 78
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Journal of natural products
- Publication Type :
- Academic Journal
- Accession number :
- 25832441
- Full Text :
- https://doi.org/10.1021/np500866c