Plasmodium falciparum dUTPase: studies on protein stability and binding of deoxyuridine derivatives.
Deoxyuridine triphosphate nucleotidohydrolase (dUTPase), a ubiquitous enzyme preventing a deleterious incorporation of uracil into DNA, has been thought of as a novel target for anticancer and antiviral drug design. The interaction of Plasmodium falciparum dUTPase (PfdUTPase) with deoxyuridine derivatives (dU, dUMP, dUDP and dUpNHpp) has been studied thermodynamically by both isothermal titration and differential scanning calorimetry. ITC shows no cooperativity for the binding of these derivatives. Dependencies in the binding thermodynamic parameters (enthalpy, entropy and Gibbs energy changes) with the number of phosphate groups in the nucleotide are obtained, and from the heat capacity changes no significant conformational changes upon binding are inferred. DSC shows PfdUTPase trimer is very stable but denatures irreversibly, with a more complex denaturation profile than other homologous trimeric dUTPases. The presence of magnesium ions does not influence the denaturation profile, while the presence of deoxyuridine derivatives increases the stability. The increase depends upon nucleotide concentration and type, with dUDP having the greater effect.
Quesada-Soriano
Indalecio
I
Dipartimento de Química Física, Bioquímica y Q. Inorgánica, Facultad de Ciencias Experimentales, Universidad de Almería, La Cañada de San Urbano, 04120 Almería, Spain.
Musso-Buendia
Juan Alexander
JA
Tellez-Sanz
Ramiro
R
Ruíz-Pérez
Luis Miguel
LM
Barón
Carmen
C
González-Pacanowska
Dolores
D
García-Fuentes
Luis
L
D000818:Animals; D001703:Biophysics / Q000379:methods; D002151:Calorimetry; D002152:Calorimetry, Differential Scanning; D003857:Deoxyuridine / Q000737:chemistry*; D007700:Kinetics; D008274:Magnesium / Q000737:chemistry; D008956:Models, Chemical; D009711:Nucleotides / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010963:Plasmodium falciparum / Q000378:metabolism*; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry; D011755:Pyrophosphatases / Q000737:chemistry*; D013696:Temperature
D009711:Nucleotides; D010710:Phosphates; D011506:Proteins; D011755:Pyrophosphatases; C020020:dUTP pyrophosphatase; D008274:Magnesium; D003857:Deoxyuridine