title: [Isolation and various properties of soluble and membrane-bound acid RNAse from rat brain lysosomes].
abstract: Preparations of soluble (I) and membrane-bound (II) acid RNAse with Mr 68,000 and 72,000 Da, respectively, and purified about 2000-fold were isolated from lysosome-rich fractions of rat brain large hemispheres. RNAase II differed from RNAase I by a lower temperature stability. The pH optimum (pH 5.8-6.1), temperature optimum and substrate specificity of RNAase I and II appeared to be identical. The Km values of RNAases I and II for poly(U) are 166 and 160 micrograms/ml; those for RNA--1200 and 1250 mu k/ml, respectively. RNAases I and II extensively hydrolyze soluble, polymeric RNA, rRNA from brain and yeast and poly(U) but do not influence poly(C), poly(A), poly(G), tRNA and DNA. Monovalent cations (K+, Na+, NH4+) activate both RNAase forms.
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D002850:Chromatography, Gel; D005095:Exoribonucleases / Q000032:analysis / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000201:enzymology; D008247:Lysosomes / Q000201:enzymology*; D051381:Rats; D012259:Ribonuclease, Pancreatic / Q000032:analysis / Q000302:isolation & purification*; D012995:Solubility; D013379:Substrate Specificity
chemical_list: D005095:Exoribonucleases; C022535:exoribonuclease II; D012259:Ribonuclease, Pancreatic
vernacular_title: Vydelenie i nekotorye svoĭstva rastvorimoĭ i membranosviazannoĭ kisloĭ RNKazy lizosom golovnogo mozga krys.