title: Properties of purified salivary ribonuclease, and salivary ribonuclease levels in children with cystic fibrosis and in heterozygous carriers.
abstract: Alkaline acid- and thermo-stable ribonuclease was isolated from human saliva of healthy subjects, children with cystic fibrosis, and from parents of the latter. The enzyme was purified about 180-200 times, and its ionic requirements, and specificity towards various substrates, characterized and compared with those for human pancreatic ribonuclease. The level of acid- and thermo-stable ribonuclease activity was five times higher in terms of enzyme level per ml saliva, and three times higher in terms of salivary protein, for 62% of children with cystic fibrosis, and for 73% of carrier subjects, relative to co-nrol groups. Assay of the level of this ribonuclease activity appears to be a promising diagnostic tool for detection of heterozygote carriers.
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000201:enzymology* / Q000235:genetics; D006580:Genetic Carrier Screening; D006579:Heterozygote; D006720:Homozygote; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008875:Middle Aged; D012260:Ribonucleases / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D012463:Saliva / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D012260:Ribonucleases