ISSN:
0148-7280
Keywords:
fertilization
;
zona-free egg
;
membrane polypeptides
;
radioiodination
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
The polypeptide composition of unfertilized, fertilized, and protease-treated zona-free mouse eggs was evaluated in this study. Zona-free eggs were radioiodinated by an Iodogen-catalyzed reaction. Light microscopic autoradiography of egg sections revealed that labeling was restricted to the cell surface. Labeled eggs were solubilized, and cell surface polypeptides were identified by one-dimensional SDS polyacrylamide gel electro-phoresis and autoradiography. The unfertilized egg demonstrated 8-10 peptides that incorporated125I, with major bands observed at approximately 145-150, 94, and 23 kilo-daltons (kD). Zona-free eggs fertilized in vitro and then radiolabeled demonstrated several new bands in comparison to unfertilized eggs, with a major band appearing at approxi mately 36 kD. Treatment of radiolabeled unfertilized eggs with either trypsin or chymo-trypsin (1 mg/ml for 5-20 min) caused enzyme-specific modifications in labeled polypep tides. Trypsin (T) treatment resulted in time-dependant modification of the three major peptides at 145-150,94, and 23 kD. Chymotrypsin (CT) treatment, in contrast, was asso ciated with loss or modification of the 94 kD band, with no apparent effect on either the 145-150 or 23 kD band. Taken together with previous data indicating that T or CT egg treatment interferes with sperm-egg attachment and fusion (Boldt et al.: Biol Reprod 39:19-27, 1988), these results suggest a possible role for the 94 kD protein in sperm-egg interaction.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1120230109
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