Expression of human placental ribonuclease inhibitor in Escherichia coli.
Human placental ribonuclease inhibitor (PRI) has been expressed in and isolated from Escherichia coli. Its apparent molecular weight, immunoreactivity and amino acid composition are virtually identical with those of native PRI. It inhibits the enzymatic activities of either angiogenin, a blood vessel inducing protein homologous to pancreatic RNase (RNase A), or RNase A in a stoichiometry of 1:1. Recombinant PRI binds to angiogenin and RNase A with Ki values of 2.9 x 10(-16) M and 6.8 x 10(-14) M, respectively, comparable to the affinities of native PRI for these enzymes. Thus, these results confirm that PRI inhibits angiogenin more effectively than RNase A.
Lee
F S
FS
Department of Biological Chemistry, Harvard Medical School, Boston, Massachusetts 02115.
Vallee
B L
BL
D000596:Amino Acids / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D007700:Kinetics; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D010926:Placental Hormones / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000096:biosynthesis*; D012259:Ribonuclease, Pancreatic / Q000037:antagonists & inhibitors / Q000378:metabolism; D012260:Ribonucleases / Q000037:antagonists & inhibitors; D014169:Transformation, Bacterial
D000596:Amino Acids; D009363:Neoplasm Proteins; D010926:Placental Hormones; D011994:Recombinant Proteins; C022052:placental ribonuclease inhibitor; D012260:Ribonucleases; C046366:angiogenin; D012259:Ribonuclease, Pancreatic