title: Alkaline ribonuclease associated with polyribosomes in fibroblasts of experimental granulation tissue.
abstract: Alkaline ribonuclease (RNase) from polyribosomes derived from experimental granulation tissue has been purified 1900-fold through affinity chromatography. The preparation was homogeneous in sodium dodecyl sulfate (SDS) polyacrylamide-gel electrophoresis with an estimated molecular weight of 15 000. Purified RNase was completely inhibited in the presence of divalent ions Mg2+(100 mM) and Ca2+(100 mM) but activated slightly with Na+(50 mM). The enzyme is an endonuclease and the best substrates were poly(U), mixed RNA from yeast, rRNA from granulation tissue and poly(C). The estimated apparent Km-values were 0.037, 0.064, 0.13 and 0.27 g1-1, respectively. In polyribosomes RNase occurred in both free and p-chloromercuribenzoate (pCMB)-liberated forms. The total activity was at the highest but the proportion of the free activity minimal in the granulation tissue during the maximal synthesis of collagen.
mesh_terms: D000818:Animals; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D005260:Female; D005347:Fibroblasts / Q000201:enzymology; D006097:Granulation Tissue / Q000201:enzymology*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008970:Molecular Weight; D011132:Polyribosomes / Q000201:enzymology*; D051381:Rats; D012260:Ribonucleases / Q000302:isolation & purification
chemical_list: D007477:Ions; D012260:Ribonucleases