7RN3

hyen D solution structure

Summary for 7RN3

• Entry DOI: 10.2210/pdb7rn3/pdb
• NMR Information: BMRB: 30938
• Descriptor: Cyclotide hyen-D (1 entity in total)
• Functional Keywords: cyclotides, plant protein
• Biological source: Hybanthus enneaspermus (Spade flower, Viola enneasperma)
• Total number of polymer chains: 1
• Total formula weight: 3182.78

Authors

Du, Q.,Huang, Y.H.,Craik, D.J.,Wang, C.K. (deposition date: 2021-07-29, release date: 2022-03-02, Last modification date: 2024-11-13)

Primary citation

Du, Q.,Huang, Y.H.,Wang, C.K.,Kaas, Q.,Craik, D.J.
Mutagenesis of bracelet cyclotide hyen D reveals functionally and structurally critical residues for membrane binding and cytotoxicity.
J.Biol.Chem., 298:101822-101822, 2022

PubMed Abstract: Cyclotides have a wide range of bioactivities relevant for agricultural and pharmaceutical applications. This large family of naturally occurring macrocyclic peptides is divided into three subfamilies, with the bracelet subfamily being the largest and comprising the most potent cyclotides reported to date. However, attempts to harness the natural bioactivities of bracelet cyclotides and engineer-optimized analogs have been hindered by a lack of understanding of the structural and functional role of their constituent residues, which has been challenging because bracelet cyclotides are difficult to produce synthetically. We recently established a facile strategy to make the I11L mutant of cyclotide hyen D that is as active as the parent peptide, enabling the subsequent production of a series of variants. In the current study, we report an alanine mutagenesis structure-activity study of [I11L] hyen D to probe the role of individual residues on peptide folding using analytical chromatography, on molecular function using surface plasmon resonance, and on therapeutic potential using cytotoxicity assays. We found that Glu-6 and Thr-15 are critical for maintaining the structure of bracelet cyclotides and that hydrophobic residues in loops 2 and 3 are essential for membrane binding and cytotoxic activity, findings that are distinct from the structural and functional characteristics determined for other cyclotide subfamilies. In conclusion, this is the first report of a mutagenesis scan conducted on a bracelet cyclotide, offering insights into their function and supporting future efforts to engineer bracelet cyclotides for biotechnological applications.

PubMed: 35283188
DOI: 10.1016/j.jbc.2022.101822

Experimental method

SOLUTION NMR