Partial purification and properties of neutral PTHase from the cytosolic fraction of rat renal cortex.
A possible new enzyme, a cytosolic neutral PTH-degrading enzyme previously described by us, was purified by ammonium sulfate fractionation, Sephadex G-200 column chromatography and DEAE cellulose column chromatography from the 100,000 x g supernatant of rat kidney. Three active peaks (designated P-I, P-II and P-III) were obtained through a DEAE cellulose chromatographic column. These three activity peaks were interchangeable on rechromatography. Further characterization of the major P-II fraction was attempted. When PTH was used as the substrate, this enzyme preparation (P-II) was inhibited by Ca2+, ATP and glutathione (GSH), but not by trypsin inhibitor, PMSF, E-64, leupeptin, chymostatin or pepstatin. This enzyme preparation could hardly hydrolyze several synthetic analogs containing MCA but not Leu-MCA and Z-Phe-Arg-MCA. When Z-Phe-Arg-MCA was used as the substrate, this enzyme preparation was activated by ATP and GSH, while no activation was induced when PTH was used. These results indicate that the neutral PTH-degrading enzyme seems to represent a new PTHase capable of specifically splitting PTH at certain locations.
Sase
M
M
Department of Medicine, Kobe University School of Medicine, Japan.
Fukushima
M
M
Nishii
Y
Y
Baba
H
H
Fujita
T
T
D000818:Animals; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D003600:Cytosol / Q000201:enzymology*; D010450:Endopeptidases / Q000032:analysis / Q000302:isolation & purification*; D007672:Kidney Cortex / Q000201:enzymology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D010450:Endopeptidases; C058334:parathyroid hormone-degrading enzyme