An assay for assessing the proteolysis of IGFBP-3 by a biological fluid or protein has been developed using 125I hIGFBP-3 recombinantly derived from Escherichia coli as a substrate indicator. The labelled substrate is incubated at 37° in the presence of the agent being tested and proteolysis is visualized by SDS-PAGE and autoradiography. The assay showed that the pregnancy associtatcd protease is Ca++ dependent. The substrate is also proteolyed by rat and mouse pregnancy sera, making the assay applicable to studies in those animal systems.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Clinical Biochemistry
- Biochemistry, medical