Studies on Human Pregnancy-Induced Insulin-Like Growth Factor (IGF)-Binding Protein-4 Proteases in Serum: Determination of IGF-II Dependency and Localization of Cleavage Site1
| Autor: | Xuezhong Qin, Dongwon Byun, Subburaman Mohan, Kyoil Suh, Myung Hi Yoo, Hae-Hyeog Lee, Chul-Hee Kim, David J. Baylink |
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| Rok vydání: | 2000 |
| Předmět: |
Proteases
medicine.medical_specialty Protease biology medicine.diagnostic_test Endocrinology Diabetes and Metabolism medicine.medical_treatment Proteolysis Growth factor Biochemistry (medical) Clinical Biochemistry Biochemistry Insulin-like growth factor-binding protein Insulin-like growth factor Endocrinology In vivo Insulin-like growth factor 2 Internal medicine biology.protein medicine hormones hormone substitutes and hormone antagonists |
| Zdroj: | The Journal of Clinical Endocrinology & Metabolism. 85:373-381 |
| ISSN: | 1945-7197 0021-972X |
| DOI: | 10.1210/jcem.85.1.6319 |
| Popis: | Insulin-like growth factor (IGF)-binding protein-4 (IGFBP-4), a consistent inhibitor of IGF action, is subject to proteolytic cleavage by the IGF-II-dependent IGFBP-4 protease. However, regulation of the IGF-II-dependent IGFBP-4 protease in vivo is not known. As IGFBP proteases are known to be triggered during pregnancy, we systematically evaluated the changes in IGFBP-4 proteolysis by serum collected throughout human pregnancy. Results from in vitro protease assays using recombinant IGFBP-4 revealed that IGFBP-4 proteolysis determined in both the presence and absence of exogenous IGF-II significantly increased during the first and second trimesters and reached a plateau by the third trimester. However, in the absence of IGF-II, IGFBP-4 proteolysis by pregnancy serum was only observed after prolonged incubation. IGF-II dose dependently increased IGFBP-4 proteolysis by pregnancy serum, with maximal stimulation observed at a concentration of 0.7 mol/L relative to IGFBP-4. In contrast, IGF-II at an equimolar... |
| Databáze: | OpenAIRE |
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