# ACROSOMAL ENZYMES AND THEIR ROLE IN FERTILIZATION

> **NIH NIH R01** · UNIVERSITY OF GEORGIA · 1993 · $150,110

## Abstract

The ovum is surrounded by the cumulus, the corona, the zona and vitelline
membrane.  Capacitated rabbit sperm undergo the acrosome reaction during
the passage through the cumulus.  Enzymes released following the acrosome
reaction or enzymes still bound to the vesicles composed of the plasma (PM)
and the outer acrosomal membranes (OAM) hydrolyse the cumulus matrix and
allow sperm to reach the corona cells and sperm which are left with a
limiting inner acrosomal membrane (IAM) encounter the zona pellucida.  The
sperm binding to the zona and its subsequent penetration may involve a
sequential action of binding to the zona and its subsequent penetration may
involve a sequential action of acrosomal hydrolases bound to IAM.  The
fusion of spermatozoa with vitelline membrane probably involves
phospholipases of the persistent PM and OAM on the equatorial segment (ES)
and the post acrosomal region (PAR).  The subsequent exocytosis of corticle
granules may also be triggered by sperm enzymes.  This sequence of events
provides the rationale for this proposal.  The overall objective of this
proposal is to elucidate further the role of acrosomal enzymes in
fertilization.  Specifically, we will isolate and compare enzymes
associated with acrosomes; determine the localization of key enzymes
involved in sperm-egg binding; isolate acrosomal enzymes from rabbit
spermatozoa and determine their effects on rabbit ova.  After the
extraction of acrosomal enzymes, sperm still contain nearly one-half of
neuraminidase, one third of arylsulfatase, and one third of hyaluronidase.
these enzymes can be extracted by further extraction of the denuded sperm
with 1% Triton X-100 and 0.1 M CaCl2.  This treatment also solubilizes the
equatorial segment.  We will follow this extraction procedure by studying
simultaneous changes in sperm morphology at the ultrastructural level.  In
view of increasing importance of glycosyltransferase and sialic acid in
gamete interactions, we will attempt localization of these and other
acrosomal enzymes by immunofluorescence, radiolabeling, and cytochemical
techniques.  The enzyme purification will employ affinity chromatography on
hydrophobic columns, high pressure liquid chromatography coupled with
conventional methods.  The role of acrosomal enzymes in sperm-egg binding,
and the ovum penetration will be studied.

Enzymes will also be tested on isolated zona.

## Key facts

- **NIH application ID:** 2197147
- **Project number:** 5R01HD014947-11
- **Recipient organization:** UNIVERSITY OF GEORGIA
- **SAM.gov UEI:** NMJHD63STRC5
- **Principal Investigator:** PRAKASH N SRIVASTAVA
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $150,110
- **Award type:** 5
- **Project period:** 1980-04-01 → 1995-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2197147

## Citation

> US National Institutes of Health, RePORTER application 2197147, ACROSOMAL ENZYMES AND THEIR ROLE IN FERTILIZATION (5R01HD014947-11). Retrieved via MORVS 2026-10-26 from https://api.morvs.ai/grant/nih/2197147. Licensed CC0.

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