Purification and characterization of a 32-kDa protein that localizes to the sea urchin extraembryonic matrix, the hyaline layer.
We have purified a 32 kilodalton (kDa) protein that localized with isolated, intact hyaline layers prepared from 1-h-old embryos. The protein appeared not to bind calcium and was not quantitatively released from 1-h-old embryos in the absence of Ca2+ and Mg2+. Using polyclonal antiserum prepared against the 32-kDa protein, the antigen was detected throughout embryonic development. By the hatched blastula stage of development, the 32-kDa protein was replaced by a species of slightly smaller molecular mass. Quantitative determination indicated that the 32-kDa protein accounted for approximately 6% of the total protein present in the sea urchin egg. This result is suggestive of a structural role for the 32-kDa protein that is required throughout embryonic development, although perhaps in a modified form from the hatched blastula stage on.
Robinson
J J
JJ
Department of Biochemistry, Memorial University of Newfoundland, St. John's, Canada.
D000818:Animals; D001755:Blastocyst / Q000737:chemistry; D002118:Calcium / Q000378:metabolism; D002850:Chromatography, Gel; D004527:Egg Proteins / Q000302:isolation & purification; D005314:Embryonic and Fetal Development; D005109:Extracellular Matrix / Q000737:chemistry*; D005775:Gastrula / Q000737:chemistry; D008274:Magnesium / Q000378:metabolism; D008970:Molecular Weight; D009865:Oocytes / Q000737:chemistry; D011485:Protein Binding; D012617:Sea Urchins / Q000737:chemistry / Q000196:embryology*
D004527:Egg Proteins; D008274:Magnesium; D002118:Calcium