Nucleic acid-protein interactions. Degradation of double-stranded RNA by glycosylated ribonucleases.
1. Extensively glycosylated ribonucleases, like the enzymes from pig and horse pancreas, show a much higher activity on double-stranded RNAs than similarly charged, carbohydrate-free RNAases under stranded assay conditions (relatively high salt concentrations). Glycosylated pig and horse pancreas RNAases also show a larger destabilizing effect on double-stranded poly[d(A-T)] X poly[d(A-T)], than that displayed by bovine RNAase A under these conditions. Both activities show a similar dependence on the ionic strength of the medium. 2. A partial enzymic removal of the heterosaccharide side chains from pig and horse RNAases reduces but their degradative activity on double-stranded RNA and their destabilizing action on poly[d(A-T)] X poly[d(A-T)]. 3. These results are tentatively correlated with a modification of the microenvironment of the enzyme protein caused by its extensive glycosylation.
D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002417:Cattle; D006224:Cricetinae; D006023:Glycoproteins / Q000378:metabolism*; D006168:Guinea Pigs; D006736:Horses; D009691:Nucleic Acid Denaturation; D010179:Pancreas / Q000201:enzymology; D011067:Poly dA-dT; D012330:RNA, Double-Stranded; D012260:Ribonucleases / Q000378:metabolism*; D013045:Species Specificity; D013379:Substrate Specificity; D013552:Swine
D002241:Carbohydrates; D006023:Glycoproteins; D012330:RNA, Double-Stranded; D011067:Poly dA-dT; D012260:Ribonucleases