Arginine decarboxylase from a Pseudomonas species.
An arginine decarboxylase has been isolated from a Pseudomonas species. The enzyme is constitutive and did not appear to be repressed by a variety of carbon sources. After an approximately 40-fold purification, the enzyme appeared more similar in its properties to the Escherichia coli biosynthetic arginine decarboxylase than to the E. coli inducible (biodegradative) enzyme. The Pseudomonas arginine decarboxylase exhibited a pH optimum of 8.1 and an absolute requirement of Mg2+ and pyridoxal phosphate, and was inhibited significantly at lower Mg2+ concentrations by the polyamines putrescine, spermidine, and cadaverine. The Km for L-arginine was about 0.25 mM at pH 8.1 AND 7.2. The enzyme was completely inhibited by p-chloromercuribenzoate. The inhibition was prevented by dithiothreitol, a feature that suggests the involvement of an -SH group. Of a variety of labeled amino acids tested, only L-arginine, but not D-arginine was decarboxylated. D-Arginine was a potent inhibitor of arginine decarboxylase with a Ki of 3.2 muM.
D000625:Aminooxyacetic Acid / Q000494:pharmacology; D000645:Ammonium Sulfate; D001120:Arginine / Q000378:metabolism; D002262:Carboxy-Lyases / Q000302:isolation & purification / Q000378:metabolism; D002474:Cell-Free System; D005591:Chemical Fractionation; D002729:Chloromercuribenzoates / Q000494:pharmacology; D002850:Chromatography, Gel; D004492:Edetic Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000378:metabolism; D011073:Polyamines / Q000494:pharmacology; D011549:Pseudomonas / Q000201:enzymology*; D011732:Pyridoxal Phosphate / Q000378:metabolism; D013237:Stereoisomerism
D002729:Chloromercuribenzoates; D011073:Polyamines; D000625:Aminooxyacetic Acid; D011732:Pyridoxal Phosphate; D001120:Arginine; D004492:Edetic Acid; D002262:Carboxy-Lyases; D008274:Magnesium; D000645:Ammonium Sulfate