title: The effects from combining urea and an alcohol on the heat-induced reversible denaturation of ribonuclease.
abstract: The effects of a combination of an alcohol and urea on the transition temperature of bovine ribonuclease were investigated. The combined effects on the transition temperature of ribonuclease of a polyvalent alcohol and urea are about equal to the algebraic sum of the effects of each individual additive. The effects of a monovalent alcohol and urea are not cummulative, especially not at low temperatures (30 degrees C). The presence of urea decreases the hydrophobic effect of a monovalent alcohol, strongly at low temperatures, to a lesser degree at high temperatures (60 degrees C). Consequently, urea hinders the interhydrophobic interactions by affecting the water molecules.
mesh_terms: D000433:1-Propanol / Q000494:pharmacology; D000438:Alcohols / Q000494:pharmacology*; D000818:Animals; D000440:Butanols / Q000494:pharmacology; D002417:Cattle; D004347:Drug Interactions; D000431:Ethanol / Q000494:pharmacology; D005026:Ethylene Glycols / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D006358:Hot Temperature; D000432:Methanol / Q000494:pharmacology; D011489:Protein Denaturation / Q000187:drug effects*; D012260:Ribonucleases / Q000378:metabolism*; D013012:Sorbitol / Q000494:pharmacology; D014508:Urea / Q000494:pharmacology*
chemical_list: D000438:Alcohols; D000440:Butanols; D005026:Ethylene Glycols; D000431:Ethanol; D013012:Sorbitol; D014508:Urea; D000433:1-Propanol; D012260:Ribonucleases; D005990:Glycerol; D000432:Methanol