title: An arginine regulated gamma-guanidobutyrate ureahydrolase from tench liver (Tinca tinca L.).
abstract: A gamma-guanidobutyrate ureahydrolase isolated from tench liver has been characterized. Some of its physicochemical properties like pH effect and thermal stability resemble those of arginases, however it shows some peculiarities that makes it different from arginases and other amidino hydrolases. Thus cation requirement is not as strong as in arginases, and the Km value for gamma-guanido-butyric acid (230 +/- 25 mM) is shifted to a lower value (45 +/- 5 mM) by 5 mM arginine. The possible regulatory role of arginine on gamma-guanidobutyrate ureahydrolase activity is discussed.
authors.affiliation: Dept. de Bioquímica y Biología Molecular y Genética, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: Campo
authors.forename: J M
authors.initials: JM
authors.lastname: Fuentes
authors.forename: G
authors.initials: G
authors.lastname: Soler
mesh_terms: D000818:Animals; D001120:Arginine / Q000502:physiology*; D002413:Cations, Divalent / Q000494:pharmacology; D003530:Cyprinidae / Q000378:metabolism*; D004795:Enzyme Stability / Q000502:physiology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D013379:Substrate Specificity; D014512:Ureohydrolases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D002413:Cations, Divalent; D001120:Arginine; D014512:Ureohydrolases; C020835:guanidinobutyrase