# Novel approaches to understanding precursor protease autoprocessing in intact viruses

> **NIH NIH R01** · CASE WESTERN RESERVE UNIVERSITY · 2020 · $516,213

## Abstract

Project Abstract
This project aims to use two highly novel and powerful assays to investigate HIV-1 protease (PR) precursor
dimerization and autoprocessing in the context of intact viruses. In contrast to studies of the mature PR, little is
known about how the precursor PR is activated and regulated, particularly under physiological conditions. We
have developed a flow virometry-based assay that enables high-throughput analysis and sorting of individual
viral particles and provides a rapid and efficient method for identifying determinants of precursor PR activation.
To complement this method, we have also developed a selective reaction monitoring-mass spectrometry
(SRM-MS) assay that allows simultaneous monitoring of all Gag and Gag-Pol cleavage sites with extremely
accurate quantification of cleavage site processing efficiency. We will use these assays to:
Aim 1: Identify determinants of precursor PR autoprocessing in the context of intact viruses.
Aim 2: Determine the timing of PR activation in relation to budding, and define how premature activation of
precursor PR activity is regulated.
Aim 3: Evaluate how drug resistance and accessory mutations affect processing, budding, and the infectivity
of viruses under physiological conditions.

## Key facts

- **NIH application ID:** 9901451
- **Project number:** 5R01AI140847-02
- **Recipient organization:** CASE WESTERN RESERVE UNIVERSITY
- **Principal Investigator:** John Christian Tilton
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $516,213
- **Award type:** 5
- **Project period:** 2019-04-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9901451

## Citation

> US National Institutes of Health, RePORTER application 9901451, Novel approaches to understanding precursor protease autoprocessing in intact viruses (5R01AI140847-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9901451. Licensed CC0.

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