Proteinase activities in bovine atrium and the possible role of mast cell tryptase in the processing of atrial natriuretic factor (ANF).
1. Using low salt, Triton X-100 and high salt extracts of bovine atria, two main proteinases were identified by means of fluorogenic oligopeptide substrates. 2. An acidic proteinase, extracted in low salt and Triton X-100 was identified as cathepsin B, but it caused little hydrolysis of the Z-Gly-Pro-Arg- containing substrate that resembles the cleavage site for activation of pro-ANF. 3. An alkaline proteinase was extracted only with high salt and had characteristics of the serine proteinase tryptase. It cleaved Z-Gly-Pro-Arg- containing substrates more efficiently than others tested and was localized in and around mast cells histochemically. Previously, Imada et al., 1988 (J. biol. Chem. 263, 9515-9519) found an identical enzyme would cleave ANF from pro-ANF. 4. These results suggest therefore that mast cell tryptase may be involved in the activation of ANF from pro-ANF.
Proctor
G B
GB
Department of Oral Pathology, King's College School of Medicine and Dentistry, Rayne Institute, London, UK.
Chan
K M
KM
Garrett
J R
JR
Smith
R E
RE
D000595:Amino Acid Sequence; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D002417:Cattle; D010450:Endopeptidases / Q000378:metabolism*; D006325:Heart Atria / Q000201:enzymology*; D008407:Mast Cells / Q000201:enzymology*; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D013379:Substrate Specificity
D011498:Protein Precursors; D009320:Atrial Natriuretic Factor; D010450:Endopeptidases; D010447:Peptide Hydrolases; C023073:tosylarginine methyl ester hydrolase