Partial purification and characterization of a binding protein for biologically active phorbol and ingenol esters from murine sera
We have purified a protein (Mr approximately 71,000) from murine sera 104-fold which directly binds biologically active phorbol esters, ingenol esters, and mezerein in a specific, reversible, and saturable manner. The binding of labeled phorbol-12,13-dibutyrate (PDBu) to the purified protein is rapi...
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Published in | The Journal of biological chemistry Vol. 257; no. 1; pp. 439 - 445 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Bethesda, MD
American Society for Biochemistry and Molecular Biology
01.01.1982
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Subjects | |
Online Access | Get full text |
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Summary: | We have purified a protein (Mr approximately 71,000) from murine sera 104-fold which directly binds biologically active phorbol
esters, ingenol esters, and mezerein in a specific, reversible, and saturable manner. The binding of labeled phorbol-12,13-dibutyrate
(PDBu) to the purified protein is rapid and dose-dependent. Those phorbol and ingenol esters which stimulate cell growth in
culture and have tumor-promoting activity in vivo inhibit the binding of labeled PDBu, while the biologically inactive derivatives
fail to do so. Other nonditerpene tumor promoters, retinoids, steroids, and prostaglandins do not interfere with PDBu-protein
interaction. Epidermal growth factor, insulin, bovine serum albumin, hemoglobin, ovalbumin, ferritin, myoglobin, fetuin, and
lipase do not interact directly with PDBu. The purified binding protein competitively inhibits the binding of PDBu to its
specific receptors. It is nonglycosylated and slightly hydrophobic. The protein is heat- and acid-labile and is present in
sera of various mammalian species. Its concentration in murine sera is age-, sex-, and strain-independent. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/S0021-9258(19)68384-5 |