Atrioactivase, a specific peptidase in bovine atria for the processing of pro-atrial natriuretic factor. Purification and characterization.
A seryl protease which catalyzes conversion of proatrial natriuretic factor (ANF) to the active circulating form, ANF(99-126), was purified from a particulate fraction of bovine atria. The enzyme was solubilized with 1.6 M KCl. The molecular mass of the purified enzyme was 580 kDa on gel filtration, whereas by sodium dodecyl sulfate-polyacrylamide gel electrophoresis a cluster of six bands with molecular masses around 30 kDa was observed. The purified enzyme produced ANF(99-126) from partially purified bovine pro-ANF by the selective cleavage of the arginyl peptide bond in the -Pro97-Arg98-Ser99-sequence in pro-ANF. The enzyme was localized mainly in the microsomal fraction rather than the granule fraction. It is likely that the enzyme selectively cleaves the Arg98-Ser99 peptide bond in pro-ANF during the process of secretion.
Imada
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T
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
Takayanagi
R
R
Inagami
T
T
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000235:genetics* / Q000378:metabolism; D002417:Cattle; D006325:Heart Atria / Q000201:enzymology; D008970:Molecular Weight; D009206:Myocardium / Q000201:enzymology*; D011480:Protease Inhibitors / Q000494:pharmacology; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology
D011480:Protease Inhibitors; D011498:Protein Precursors; D009320:Atrial Natriuretic Factor; D012697:Serine Endopeptidases; C056294:atrioactivase