TitleMass spectrometric analysis of cyclotides from Clitoria ternatea: Xxx-Pro bond fragmentation as convenient diagnostic of Pro residue positioning.
Publication TypeJournal Article
Year of Publication2021
AuthorsVenkatesan R, Balaram P, Kalmankar NV
JournalChem Asian J
Date Published2021 Jul 20
ISSN1861-471X
Abstract

Cyclotides, a class of macrocyclic plant peptides, characterized by a cyclic backbone and three inter-locking disulfide bonds, may be divided into two structural subfamilies, Möbius and Bracelet, based on presence or absence of a specific proline residue. The present study describes the suite of cyclotides obtained from Clitoria ternatea , characterized by LC-MS and MS/MS techniques. Notable variations in product ion distributions were observed in cyclotides belonging to different structural subfamilies based on the number and positions of proline residues. For instance, Cter M which is an abundant Möbius cyclotide in this plant containing three proline residues, displayed distinct b- and y- ion characteristics in the MS/MS spectra compared to Cliotide T1, another commonly identified cyclotide but belonging to the Bracelet subfamily having two proline residues. The distinct fragmentation pattern of prototypical cyclotides of each structural subfamily, determined by Xxx-Pro bond fragmentation, was used to rapidly identify and sequence a novel cyclotide ctr pep 30 from this plant.

DOI10.1002/asia.202100585
Alternate JournalChem Asian J
PubMed ID34288513