Neutral protease cleaving the N-terminal propeptide of type III procollagen: partial purification and characterization of the enzyme from smooth muscle cells of bovine aorta.
Procollagen type III amino-terminal protease was detected in cultures of smooth muscle cells of fetal calf aorta, and this protease was purified about 400-fold. Only about half of the enzyme activity was consistently attached to concanavalin A-agarose (Con A-agarose). After affinity chromatography on type III pN-collagen-Sepharose, the Con A bound fraction showed only one major band with a molecular weight of about 72000, this value corresponding well with the elution position of enzyme activity in gel filtration. The enzyme did not cleave procollagens type I or type IV, and denatured type III pN-collagen also remained uncleaved. The Km of the enzyme activity for iodo[14C]acetamide-labeled type III pN-collagen was 0.76 microM. Neutral pH and Ca2+ wer required for maximal enzymic activity. The metal chelators ethylenediaminetetraacetic acid and ethylene glycol bis(beta-amino-ethyl ether)-N,N,N',N'-tetraacetic acid inhibited the activity as well as did dithiothreitol, but there was only little if any inhibition by several other proteinase inhibitors tested.
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002846:Chromatography, Affinity; D004533:Egtazic Acid / Q000378:metabolism; D010450:Endopeptidases / Q000302:isolation & purification*; D005260:Female; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D015260:Neprilysin; D011247:Pregnancy; D011347:Procollagen / Q000378:metabolism*
D011347:Procollagen; D004533:Egtazic Acid; D010450:Endopeptidases; D015260:Neprilysin; D002118:Calcium