Bioprospecting a medicinal plant for therapeutics

• Main Author: Ho, Malcolm Zheng Hao
• Other Authors: James P Tam
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Science::Biological sciences
• Online Access: https://hdl.handle.net/10356/140947
• Institution: Nanyang Technological University

Eleutherococcus trifoliatus, a valuable medicinal plant, has been used to treat injuries and diseases for centuries. Its orally active decoction may have the presence of cysteine-rich peptides (CRPs), a 2-6 kDa, functionally diverse and hyperdisulfide mini-proteins that have therapeutic relevance. This study reports the discovery, characterisation and therapeutic bioprospection of a CRP termed eleutherotide eT3670 extracted from E. trifoliatus. eT3670 consists of 35 amino acids and possesses an 8C-cysteine motif potentially forming six inter- cysteine loops via four intramolecular disulfide bonds that confer it resistance to thermal, acidic, enzymatic and serum-mediated degradation. Transcriptomic and bioinformatics analyses revealed that eT3670 is synthesised as a three-domain precursor, its disulfide connectivity as Cys I-IV, II-VI, III-VII, V-VIII, its inter-cysteine loops tolerance to amino acid variation and that it contains a variant LC3-interacting region motif related to selective autophagy. Cell-based assays showed that eT3670 is cytoprotective and a potential adaptogen that may induce autophagy to maintain cellular homeostasis, protecting cells from hypoxia stress-mediated damage and cell death. Together, the study bioprospects eT3670 as a potential candidate to be developed as a stable orally active drug for the treatment of autophagy-related diseases and as a grafting scaffold to enhance the stability of peptidyl therapeutics.