Human placental ribonuclease inhibitor abolishes both angiogenic and ribonucleolytic activities of angiogenin.
- 1 April 1987
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 84 (8) , 2238-2241
- https://doi.org/10.1073/pnas.84.8.2238
Abstract
Human placental ribonuclease inhibitor (PRI) abolishes both the ribonucleolytic activity of angiogenin toward 28S and 18S rRNA and its angiogenic activity on the chicken embryo chorioallantoic membrane. Treatment of the angiogenin-PRI complex with p-hydroxymercuribenzoate releases enzymatically active angiogenin. Assays measuring competition between angiogenin and bovine pancreatic ribonuclease A for PRI reveal that binding of the inhibitor to angiogenin is extremely tight, with a Ki value well below 0.1 nM. The stability of the angiogenin-PRI complex was assessed by cation-exchange HPLC quantitation of free angiogenin. No significant dissociation was detected after 17 hr at 25 degrees C in the presence of a large excess of bovine ribonuclease, which serves as a scavenger for free inhibitor. The results of these experiments, based on the predictive capacity of the angiogenin/RNase homology, suggest that PRI and related inhibitors may participate in the in vivo regulation of angiogenin and that this might have pharmacologic and/or therapeutic implications.This publication has 17 references indexed in Scilit:
- Characteristic ribonucleolytic activity of human angiogeninBiochemistry, 1986
- A preliminary three-dimensional structure of angiogenin.Proceedings of the National Academy of Sciences, 1986
- Cloning and sequencing of the intronless gene for angiogenin, a human angiogenesis factorBiochemistry, 1985
- Isolation and characterization of angiogenin, an angiogenic protein from human carcinoma cellsBiochemistry, 1985
- The ribonuclease inhibitors from porcine thyroid and liver are slow, tight-binding inhibitors of bovine pancreatic ribonuclease ABiochemical and Biophysical Research Communications, 1983
- RIBONUCLEASE INHIBITOR FROM BOVINE BRAIN*International Journal of Peptide and Protein Research, 1980
- Role of mammalian RNase inhibitor in cell-free protein synthesisProceedings of the National Academy of Sciences, 1979
- A suggested control function for the animal tissue ribonuclease-ribonuclease inhibitor system, based on studies of isolated cells and phytohaemagglutinin-transformed lymphocytesBiochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, 1970
- Mechanism and binding sites in the ribonuclease reaction II. Kinetic studies on the first step of the reactionBiochemical and Biophysical Research Communications, 1962