title: A protein inhibitor of acid deoxyribonucleases.
abstract: A protein extracted and partially purified (about 100-fold) from mouse liver is able to inhibit the acid DNases from different tissues and species, whereas pancreatic DNase and E. coli endonuclease I are not inhibited. The acid DNase displays typical Michaelis-Menten kinetics in the absence of this inhibitor, but the kinetics become sigmoidal in its presence. The existence of a DNase-inhibitor complex is demonstrated by physicochemical experiments. Moreover, the inhibitor is able to reactivate the DNase treated by urea, probably through a reassociation of the inactive monomers to a dimeric state. An allosteric model in which the DNase-inhibitor complex is composed of catalytic (DNase) and regulatory (inhibitor) subunits could explain these data.
mesh_terms: D000818:Animals; D002417:Cattle; D002499:Centrifugation, Density Gradient; D003851:Deoxyribonucleases / Q000037:antagonists & inhibitors*; D004926:Escherichia coli / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D051379:Mice; D008956:Models, Chemical; D010179:Pancreas / Q000201:enzymology; D011506:Proteins; D012908:Snails / Q000201:enzymology; D013154:Spleen / Q000201:enzymology
chemical_list: D011506:Proteins; D003851:Deoxyribonucleases