title: Studies of rabbit brain, intestine and liver guanine aminohydrolase.
abstract: Guanine aminohydrolase (EC 3.5.4.3) from rabbit brain, intestine, and liver has been purified to homogeneity by affinity chromatography at room temperature and 0-4 degrees C. In all cases the recovery and fold purification was greatest for purification at room temperature. Each enzyme has a subunit mol. wt of 49,500 and crosslinking studies revealed the native form to be a dimer. The amino acid analysis showed a high content of asx, glx, ser, gly and leu; the pI was 5.0 for each prep. The Michaelis constants at pH 8.0 were 6.1, 6.1 and 5.8 X 10(-6) M for brain, intestine and liver GAH respectively. The enzymes had a broad pH activity profile with an optimum of pH 8.0-8.5.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000619:Aminohydrolases / Q000302:isolation & purification*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D055598:Chemical Phenomena; D002621:Chemistry; D002846:Chromatography, Affinity / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006148:Guanine Deaminase / Q000302:isolation & purification*; D007422:Intestines / Q000201:enzymology*; D007525:Isoelectric Focusing; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight; D010179:Pancreas / Q000201:enzymology; D011817:Rabbits; D013154:Spleen / Q000201:enzymology
chemical_list: D000596:Amino Acids; D000619:Aminohydrolases; D006148:Guanine Deaminase