title: Biochemical properties of three plant nucleases with anticancer potential.
abstract: Biochemical and structural properties of three recombinant (R), highly homologous, plant bifunctional nucleases from tomato (R-TBN1), hop (R-HBN1) and Arabis brassica (R-ABN1) were determined. These nucleases cleave single- and double-stranded substrates, as well as both RNA and DNA with nearly the same efficiency. In addition, they are able to cleave several artificial substrates and highly stable viroid RNA. They also possess 3'-nucleotidase activity; therefore, they can be classified as nuclease I family members. Interestingly, poly(G) is resistant to cleavage and moreover it inhibits dsDNase, ssDNase and RNase activity of the studied nucleases. All three nucleases exhibit zinc-dependence and a strong stimulatory effect of Zn²+ for dsDNA cleavage. 3-D models, predicted on the basis of experimental structure of P1 nuclease, show nine amino acid residues responsible for interactions with zinc atoms, located in the same positions as in P1 nuclease. It was also shown that R-TBN1, R-HBN1, and R-ABN1 are all N-glycosylated. Oligosaccharidic chains constitute about 16% of their MW. In addition, an anticancer potential of the R-ABN1 is compared in this work with previously tested R-TBN1, and R-HBN1. R-ABN1 injected intravenously showed 70% inhibitory effect on growth of human prostate carcinoma in athymic mice.
authors.affiliation: Institute of Chemical Technology Prague, Technická 3, 166 28 Prague, Czech Republic; Biology Centre, ASCR v.v.i., Institute of Plant Molecular Biology, Branišovská 32, 37005 České Budějovice, Czech Republic. podzimet@vscht.cz
authors.forename: Tomáš
authors.initials: T
authors.lastname: Podzimek
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Matoušek
authors.forename: Petra
authors.initials: P
authors.lastname: Lipovová
authors.forename: Pavla
authors.initials: P
authors.lastname: Poučková
authors.forename: Vojtěch
authors.initials: V
authors.lastname: Spiwok
authors.forename: Jiří
authors.initials: J
authors.lastname: Santrůček
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D031214:Arabis / Q000201:enzymology; D049109:Cell Proliferation / Q000187:drug effects*; D003851:Deoxyribonucleases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D006031:Glycosylation; D006801:Humans; D027582:Humulus / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D018551:Solanum lycopersicum / Q000201:enzymology; D051379:Mice; D008819:Mice, Nude; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D012260:Ribonucleases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D010940:Plant Proteins; D011994:Recombinant Proteins; D003851:Deoxyribonucleases; D012260:Ribonucleases