pH and protease control of acrosomal content stasis and release during the guinea pig sperm acrosome reaction
The purpose of this study was to examine how trypsin inhibitors affect the guinea pig sperm acrosome reaction in vitro. Using spermatozoa pretreated with lysophosphatidyl choline, we found that both naturally occurring high molecular weight and the smaller synthetic trypsin inhibitor p-aminobenzamid...
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Published in | Biology of reproduction Vol. 32; no. 2; pp. 451 - 462 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Society for the Study of Reproduction
01.03.1985
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Subjects | |
Online Access | Get full text |
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Summary: | The purpose of this study was to examine how trypsin inhibitors affect the guinea pig sperm acrosome reaction in vitro. Using
spermatozoa pretreated with lysophosphatidyl choline, we found that both naturally occurring high molecular weight and the
smaller synthetic trypsin inhibitor p-aminobenzamidine (PAB) delayed the onset of the acrosome reaction as monitored by light
microscopy. Examination with electron microscopy revealed that acrosomal matrix dispersal rather than membrane fusion was
affected. Despite the morphologic delay in acrosomal content release, PAB unexpectedly permitted 96% of soluble acrosomal
antigen to be released into the supernatant. In addition, total acrosin release in the presence of PAB was 74% of control,
with the vast majority as latent rather than active enzyme. A morphologically intact but membrane-free target of acrosomal
matrix (AM), which is sensitive to trypsin inhibitor, was partially purified using Triton-x-100 at pH 5.2. AM remained morphologically
stable at pH 5.2; however, shift up to pH 7 resulted in rapid dissolution within several minutes as monitored by light and
electron microscopy and light scattering. Trypsin inhibitor prevented dispersion of AM at pH 7. The results suggest that,
during the acrosome reaction, one distinct region of the acrosomal contents disperses after membrane vesiculation in a pH
and trypsin inhibitor-insensitive fashion while a pH sensitive trypsin-like activity (acrosin?) disperses another discrete
region of acrosomal matrix. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0006-3363 1529-7268 |
DOI: | 10.1095/biolreprod32.2.451 |