# Manipulation of sperm-specific proteases using genetic and chemical approaches

> **NIH NIH P01** · BAYLOR COLLEGE OF MEDICINE · 2020 · $317,589

## Abstract

PROJECT 3 SUMMARY (Manipulation of sperm-specific proteases using genetic and chemical approaches)
The overall goals of Project 3 are to elucidate the molecular mechanisms of action of male
reproductive tract-specific serine protease-like enzymes through the use of genetics and chemical
biology, and to use these data to guide discovery of novel non-hormonal contraceptive agents.
Biological targets ideal for drug discovery endeavors are those with significant and non-redundant biological
effects, highly specific molecular functions, and biochemical features amenable to molecular inhibition. No
single definitive methodology exists for the identification or validation of efficacious drug targets, and certainly
the processes of evolution are not driven to yield numerous physiologically vulnerable pathways, particularly
for contraception. Therefore, a thorough understanding of the molecular mechanisms governing fertility as well
as an approach that samples a wide array of intervention points is desirable. As a complement to targets
emerging from Projects 1 and 2, Project 3 will focus on the genetic and chemical analyses of five serine
protease-like enzymes with expression limited to the male reproductive tract. These mechanistic studies will
allow us to place these serine protease-like enzymes into reproductive pathways and simultaneously
determine the utility of each of these proteins as a contraceptive target. Early studies of the sperm-zona
pellucida interaction assumed that enzymes contained within the sperm acrosome were required for
penetration of cumulus cell layers and the zona pellucida. More recently, it has become apparent that whereas
the exocytotic event associated with release of acrosomal enzymes (during the acrosome reaction) is essential
for fertilization, it is neither induced by contact with the zona pellucida, nor required to occur in proximity of the
outer vestments of the oocyte. Similarly, motile sperm are essential for successful fertilization. Our overall
hypothesis is that serine protease-like enzymes are a novel class of proteins required for male fertility and the
discovery of small-molecule inhibitors for these spermatogenic-required enzymes will lead to the development
of unique male contraceptives. Our Specific Aims are as follows: 1) Use CRISPR/Cas9 models of male
reproductive tract-specific proteases to clarify their requirement in reproduction; 2) Aid in the expression and
purification of recombinant proteins from Projects 1, 2, and 3 for DNA-encoded chemistry technology (DEC-
Tec) affinity selections; and 3) Use DEC-Tec to uncover small-molecule probes and inhibitors of novel serine
protease-like enzymes required for fertility and evaluate early drug-like leads and analogues with acceptable
pharmacokinetic properties in proof-of-concept contraceptive studies in vivo.

## Key facts

- **NIH application ID:** 9941098
- **Project number:** 5P01HD087157-04
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** William Sonnenburg
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $317,589
- **Award type:** 5
- **Project period:** — → —

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9941098

## Citation

> US National Institutes of Health, RePORTER application 9941098, Manipulation of sperm-specific proteases using genetic and chemical approaches (5P01HD087157-04). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/9941098. Licensed CC0.

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