RESUMO
Nucleobase and nucleoside analogs (NNA) are widely used as anti-viral and anti-cancer agents, and NNA phosphorylation is essential for the activity of this class of drugs. Recently, diphosphatase NUDT15 was linked to thiopurine metabolism with NUDT15 polymorphism associated with drug toxicity in patients. Profiling NNA drugs, we identify acyclovir (ACV) and ganciclovir (GCV) as two new NNAs metabolized by NUDT15. NUDT15 hydrolyzes ACV and GCV triphosphate metabolites, reducing their effects against cytomegalovirus (CMV) in vitro. Loss of NUDT15 potentiates cytotoxicity of ACV and GCV in host cells. In hematopoietic stem cell transplant patients, the risk of CMV viremia following ACV prophylaxis is associated with NUDT15 genotype (P = 0.015). Donor NUDT15 deficiency is linked to graft failure in patients receiving CMV-seropositive stem cells (P = 0.047). In conclusion, NUDT15 is an important metabolizing enzyme for ACV and GCV, and NUDT15 variation contributes to inter-patient variability in their therapeutic effects.
Assuntos
Aciclovir/farmacologia , Antivirais/farmacologia , Infecções por Citomegalovirus/prevenção & controle , Ganciclovir/análogos & derivados , Pirofosfatases/genética , Aciclovir/uso terapêutico , Adolescente , Adulto , Idoso , Animais , Antibioticoprofilaxia , Antivirais/uso terapêutico , Variação Biológica da População/genética , Linhagem Celular , Criança , Pré-Escolar , Cristalografia por Raios X , Citomegalovirus/efeitos dos fármacos , Citomegalovirus/genética , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/etiologia , Infecções por Citomegalovirus/virologia , DNA Viral/sangue , DNA Viral/isolamento & purificação , Modelos Animais de Doenças , Farmacorresistência Viral , Feminino , Ganciclovir/farmacologia , Ganciclovir/uso terapêutico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Interações entre Hospedeiro e Microrganismos/genética , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Muromegalovirus/isolamento & purificação , Muromegalovirus/patogenicidade , Variantes Farmacogenômicos , Polimorfismo de Nucleotídeo Único , Pirofosfatases/metabolismo , Pirofosfatases/ultraestrutura , Resultado do Tratamento , Adulto JovemRESUMO
Inorganic pyrophosphatase was purified to homogeneity from the vacuolar membranes of pumpkin hypocotyl tissue. The purified Inorganic pyrophosphatase consists of a single kind of 75-kDa polypeptide, and the stacked molecules with a repeating unit of 5.8 x 3.8 nm are seen under electron micrography. It exhibits H(+)-translocating activity across membranes coupled with PPi hydrolysis when it is reconstituted into proteoliposomes. A monovalent cation is required for the H+ translocation with the K+ ion being the most effective, but evidence for active transport of 42K+ into proteoliposomes was not obtained under the conditions tested. The hydrolysis of PPi by the reconstituted proteoliposomes is stimulated by the addition of a H+ ionophore, carbonyl cyanide p-trifluoromethyoxyphenylhydrazone, but not by a K+ ionophore, valinomycin. Both hydrolysis of PPi and PPi-dependent H+ translocation of the proteoliposomes are inhibited by N,N'-dicyclohexylcarbodiimide.
Assuntos
Proteolipídeos/metabolismo , Pirofosfatases/isolamento & purificação , Pirofosfatases/metabolismo , Vacúolos/enzimologia , Verduras/enzimologia , Sequência de Aminoácidos , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Pirofosfatase Inorgânica , Membranas Intracelulares/enzimologia , Cinética , Lipossomos , Magnésio/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Microscopia Eletrônica , Dados de Sequência Molecular , Peso Molecular , Potássio/metabolismo , Cloreto de Potássio/farmacologia , Pirofosfatases/ultraestrutura , Homologia de Sequência de AminoácidosRESUMO
Vacuolar membrane H(+)-translocating pyrophosphatase (H(+)-PPase) was purified from pumpkin seedlings. Its enzymatic properties including molecular size of constituting polypeptide (75 kDa) were very similar to those of mung bean H(+)-PPase [(1989) J. Biol. Chem. 264, 20068-20073]. The native, functional molecular size of the pumpkin H(+)-PPase was estimated to be 135-139 kDa from gel permeation HPLC of the purified enzyme in the presence of detergent and from radiation inactivation of the enzyme in vacuolar membranes. It is concluded that native, functional pumpkin H(+)-PPase, and also probably H(+)-PPases from other plants, is a dimer of 75 kDa subunits.