# Biosynthetic Development and Diversification of Moroidin Peptides for Cancer Applications

> **NIH NIH F31** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2024 · $48,974

## Abstract

PROJECT SUMMARY
Macrocyclic peptides are effective scaffolds for cancer drug discovery because they can combine the
metabolic stability and target specificity of biologics with oral bioavailability and membrane permeability of
small molecules. The bicyclic octapeptide moroidin is a promising lead structure for anticancer therapy.
Moroidin is characterized by an N-terminal pyroglutamate and two tryptophan side-chain cross-linkages. Due
to low-yield isolation from source-plant material and synthetic challenges toward macrocyclic complexity and
chirality, an optimized biosynthetic route is needed to diversify and produce moroidin analogs in a heterologous
expression system.
Moroidin is a ribosomally synthesized and post-translationally modified peptide derived from autocatalytic
Japanese kerria peptide cyclase KjaBURP, which installs the tryptophan-crosslinks to a leucine and a histidine
side chain in a copper-dependent reaction. KjaBURP encodes four moroidin core peptide motifs attached to
the C-terminal catalytic BURP domain. Based on preliminary work, I hypothesize that the second moroidin ring
can be exploited to generate hundreds of analogs with chemopreventative potential. In Specific Aim 1,
metabolic engineering of the moroidin pathway via heterologous expression of moroidin cyclase constructs
such as KjaBURP in Nicotiana benthamiana will maximize biosynthetic access to natural moroidins and its
analogs. Specific Aim 2 seeks to generate a small library of semi-pure moroidin analogs in transgenic tobacco
by engineered KjaBURP, test their cytotoxic activity against cancer cell lines, and use various high-throughput
scoring methods to propose a mechanism of action for dose-responsive peptides. The proposed research of
moroidin pathway engineering is an approach to generate and biologically screen new plant peptide libraries
for utility in cancer drug discovery.

## Key facts

- **NIH application ID:** 10994826
- **Project number:** 1F31GM155959-01
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** Khadija Shafiq
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $48,974
- **Award type:** 1
- **Project period:** 2024-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10994826

## Citation

> US National Institutes of Health, RePORTER application 10994826, Biosynthetic Development and Diversification of Moroidin Peptides for Cancer Applications (1F31GM155959-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10994826. Licensed CC0.

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