6JIC

Identification and Characterization of a carboxypeptidase inhibitor from Lycium barbarum

Summary for 6JIC

• Entry DOI: 10.2210/pdb6jic/pdb
• Descriptor: WCI (1 entity in total)
• Functional Keywords: carboxypeptidase inhibitor, wolfberry, cysteine-rich peptide, plant protein
• Biological source: Lycium barbarum
• Total number of polymer chains: 1
• Total formula weight: 4019.48

Authors

Tan, W.L.,Wong, K.H.,Huang, J.Y.,Tay, S.V.,Wang, S.J. (deposition date: 2019-02-20, release date: 2020-02-26, Last modification date: 2024-11-06)

Primary citation

Huang, J.,Wong, K.H.,Tan, W.L.,Tay, S.V.,Wang, S.,Tam, J.P.
Identification and characterization of a wolfberry carboxypeptidase inhibitor from Lycium barbarum.
Food Chem, 351:129338-129338, 2021

PubMed Abstract: Hyperstable cysteine-rich peptides (CRPs) represent an underexplored superfamily of bioactives in functional foods. An example is wolfberry of the Lycium barbarum family. Previously, we discovered a CRP, designated α-lybatide, from L. barbarum bark. Herein, we report the discovery of β-lybatide, a novel carboxypeptidase inhibitor belonging to a different CRP family from the wolfberry plant. Proteomic and transcriptomic analyses showed that β-lybatide contains 36 amino acids with six cysteine residues. NMR spectroscopy revealed that β-lybatide displays a knottin-like structure that renders it highly resistant to thermal, chemical and enzymatic degradation, conditions important for keeping its structural integrity in gastrointestinal tract. Biochemical assays showed that β-lybatide is a potent carboxypeptidase inhibitor which could contribute to the wolfberry biological activities. Bioinformatics analysis revealed an additional 49 β-lybatide-like plant carboxypeptidase inhibitors. Together, our results show that β-lybatide is the first and the smallest plant-derived hyperstable carboxypeptidase inhibitor discovered from a functional food.

PubMed: 33647700
DOI: 10.1016/j.foodchem.2021.129338

Experimental method

SOLUTION NMR