Placental beta-endorphin-like peptides.
Acid extract of human placental tissue contain, by both radioimmunoassay and radioreceptor assay, beta-endrophin-like material. Half of this material will not go through a 5000-dalton filter and on Sephadex G-200 has a molecular size between 25,00 and 50,000 daltons. Of the material going through a 5000-dalton ultrafilter, 80 percent is excluded on Sephadex G-25 and held back, very slightly, on Bio-Rad P6, indicating a molecular size of approximately 4500 to 4800 daltons. Thus, placenta appears to have macromolecular precursors from which a beta-endorphin-like material is released, with a size approximately 12 amino acids longer than half of the pituitary hormone.
D004723:Endorphins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008970:Molecular Weight; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011863:Radioimmunoassay; D011869:Radioligand Assay
D004723:Endorphins