Human placenta cytidine deaminase: a zinc metalloprotein.
Cytidine deaminase, a tetrameric enzyme purified from human placenta, was shown to contain a single atom of tightly bound zinc per subunit by Inductively Coupled Plasma Optical Emission Spectrometry analysis. The metal appears to be involved in catalysis, as suggested by the inhibition exerted by 1,10-phenanthroline and dipicolinic acid. This hypothesis is further supported by the finding that the presence of substrate protects the enzymatic activity from dipicolinic acid inhibition. Furthermore the total cysteine residues per subunit were investigated by sulphydryl groups titrating agents.
Vincenzetti
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Dipartimento di Biologia M.C.A., Università di Camerino, Italy.
Cambi
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A
Balducci
E
E
Natalini
P
P
Volpini
R
R
Vita
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D002614:Chelating Agents / Q000494:pharmacology; D003545:Cysteine / Q000032:analysis; D003564:Cytidine Deaminase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D010618:Phenanthrolines / Q000494:pharmacology; D010848:Picolinic Acids / Q000494:pharmacology; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013438:Sulfhydryl Compounds / Q000032:analysis; D015032:Zinc / Q000032:analysis*
D001426:Bacterial Proteins; D002614:Chelating Agents; D010618:Phenanthrolines; D010848:Picolinic Acids; D013438:Sulfhydryl Compounds; D003564:Cytidine Deaminase; D015032:Zinc; D003545:Cysteine; C004860:dipicolinic acid; C025205:1,10-phenanthroline