Intersubunit interactions in human cytidine deaminase.
In order to design new efficient cytidine based drugs, an intersubunit interactions study related to the active site has been performed on the wild-type cytidine deaminase (CDA) and on the mutant enzyme F137W/W113F. F137 is the homologous to the Bacillus subtilis CDA F125 involved in the subunit interactions. In presence of the dissociating agent SDS, wild-type human CDA dissociate into enzymatically inactive monomers without intermediate forms via a non-cooperative transition. Extensive dialysis or dilution of the inactivated monomers restores completely the activity. The presence of the strong human CDA competitive inhibitor 5-fluorozebularine disfavour dissociation of the tetramer into subunits in the wild-type CDA but not in mutant enzyme F137W/W113F.
Vincenzetti
S
S
Dipartimento di Scienze Veterinarie, University of Camerino, Matelica (MC), Italy.
Costanzi
S
S
Cristalli
G
G
Mariani
P
P
Quadrini
B
B
Cammertoni
N
N
Vita
A
A
D019943:Amino Acid Substitution; D001412:Bacillus subtilis / Q000201:enzymology; D002850:Chromatography, Gel; D003564:Cytidine Deaminase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D021122:Protein Subunits; D011994:Recombinant Proteins; D003564:Cytidine Deaminase