# Dual protease activated peptides for specific targeting

> **NIH NIH F32** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2023 · $69,080

## Abstract

Project Summary/Abstract
 Here we develop a platform for protease-activated peptide prodrugs. We initially focus the effort on
antimicrobial peptides (AMP), which have a broad spectrum of cell-penetrating, antimicrobial and cytotoxic
activities. However, they have multiple limitations, including off-target cytotoxicity and proteolytic instability. To
circumvent these unwanted effects, linear protease-activated prodrugs have been employed. Although effective
at enhancing the activity of the active payload, it does not adequately address the side effects stated above. To
mitigate the side effects of the traditional protease-activated prodrug approach, the proposed research strategy
herein seeks to design a branched protease-activated prodrug by coupling a cleavable linker to the sidechains
of amino acid residue that significantly impacts antimicrobial peptide activity. As a proof-of-concept, bombolitin
(an AMP that is cytotoxic to mammalian cells) will be used as the payload, masked with caspase-3 and fibroblast
activation protein (cancer biomarkers) substrate-specific linkers. By modifying the sidechains of Lys, Ser, Thr,
and Tyr with these linkers, we hypothesize that the physicochemical properties of bombolitin will be significantly
altered, thus reducing peptide-membrane interaction until activation. In this research, we propose to 1) design
and synthesize single and double-branched protease-activated prodrugs cleaved in the presence of either
caspase-3 and/or fibroblast activation protein to yield the active peptide, 2) confirm caspase-3 and fibroblast
activation protein cleavage of linker from prodrugs by performing in vitro enzymatic assays and biophysical
analysis, and 3) perform cell-based assays to validate prodrug cleavage, target specificity, activity enhancement,
and reduction of off-target effects.

## Key facts

- **NIH application ID:** 10680341
- **Project number:** 1F32GM150255-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Ethel Naa Odey Tackie-Yarboi
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $69,080
- **Award type:** 1
- **Project period:** 2023-07-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10680341

## Citation

> US National Institutes of Health, RePORTER application 10680341, Dual protease activated peptides for specific targeting (1F32GM150255-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10680341. Licensed CC0.

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