Pregnancy-Associated Plasma Protein-A

**Definition:** A product of the PLACENTA, and DECIDUA, secreted into the maternal circulation during PREGNANCY. It has been identified as an IGF binding protein (IGFBP)-4 protease that proteolyzes IGFBP-4 and thus increases IGF bioavailability. It is found also in human FIBROBLASTS, ovarian FOLLICULAR FLUID, and GRANULOSA CELLS. The enzyme is a heterotetramer of about 500-kDa.

**Tree numbers:** - D08.811.277.656.300.480.632 - D08.811.277.656.675.374.632 - D12.776.780.700

**Synonyms:** - IGFBP-4 Protease - IGFBP-4-Specific Proteinase - Insulin-Like Growth Factor-Dependent IGF Binding Protein-4 Protease - Insulin-Like-Growth Factor Binding Protein-4 Protease - IGFBP-4 Metalloproteinase - PAPP-alpha - Pregnancy Associated alpha Plasma Protein - Pregnancy-Associated alpha-Plasma Protein - PAPP-A