期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1982
卷号：79
期号：6
页码：2086-2090
DOI：10.1073/pnas.79.6.2086
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Multiple molecular forms of immunoreactive corticotropin (ACTH) and {beta}-endorphin were present in extracts of a unicellular eukaryote (Tetrahymena pyriformis). One form of immunoreactive ACTH reacted similarly with two different ACTH antisera (one specific for the 11-24 sequence and the other with determinants within sequences 1-14 and 17-39) and migrated with synthetic hACTH-(1-39) in a gel filtration system. This form also exhibited ACTH bioactivity in a dispersed rat adrenal cell bioassay system, with a mean immunoassay/bioassay ratio of 1.5. Gel filtration revealed multiple size classes of immunoreactive {beta}-endorphin; a major peak of radioreceptor activity was detected which exhibited a Kav similar to that of authentic {beta}-endorphin. A major portion of immunoreactive {beta}-endorphin-sized material exhibited retention times similar to those of synthetic human and camel {beta}-endorphin upon reverse-phase high-pressure liquid chromatography. These distinctive properties and specificities would seem to exclude the presence of limited homologies with sequences present in other proteins. High molecular weight material containing both ACTH and {beta}-endorphin antigenic determinants was also demonstrated, suggesting, but not proving, the presence of a common precursor molecule.
