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Publication Abstract from PubMed

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 alpha-lybatide, from L. barbarum bark. Herein, we report the discovery of beta-lybatide, a novel carboxypeptidase inhibitor belonging to a different CRP family from the wolfberry plant. Proteomic and transcriptomic analyses showed that beta-lybatide contains 36 amino acids with six cysteine residues. NMR spectroscopy revealed that beta-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 beta-lybatide is a potent carboxypeptidase inhibitor which could contribute to the wolfberry biological activities. Bioinformatics analysis revealed an additional 49 beta-lybatide-like plant carboxypeptidase inhibitors. Together, our results show that beta-lybatide is the first and the smallest plant-derived hyperstable carboxypeptidase inhibitor discovered from a functional food.

Identification and characterization of a wolfberry carboxypeptidase inhibitor from Lycium barbarum.,Huang J, Wong KH, Tan WL, Tay SV, Wang S, Tam JP Food Chem. 2021 Feb 19;351:129338. doi: 10.1016/j.foodchem.2021.129338. PMID:33647700^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.