DNA covalent

I topoisomerase of mammals is a 100 kD monomeric protein whose activity is ATP-independent. This enzyme binds to double-stranded DNA and cleaves one of the DNA strands of the duplex, simultaneously forming an enzyme-DNA covalent bond between a tyrosine residue and the 3 -phosphate of the cleaved DNA. The type II topoisomerases are dimeric enzymes, which are ATP-dependant. Two isoforms of topoisomerase II exist, topoisomerase a and (3, with apparent molecular weights of 170 and 180 kD. Topoisomerase... 

Streptavidin-single-stranded DNA covalent conjugates were described as the building blocks for assembling nanostructured scaffolds [31], The amount and type of biotinylated ligands were used to modulate the affinity of duplex formation between solid-phase-bound nucleic acid templates and DNA-streptavidin conjugates. This system has been proposed for the design of fine-tuned sequence detection systems. 

In an effort to improve the water solubility of camptothecin, Rahier et al. [50] synthesized four 20-O-phosphate derivatives (VI). These compounds are freely water-soluble, stable to physiological pH, and stabilize the human topo I-DNA covalent binary complex with the same sequence-selectivity as camptothecin itself All four compounds inhibited the growth... 

As mentioned in the introduction, the prototype o-QM is a highly reactive intermediates in organic reactions, including cycloaddition chemistry and DNA covalent modification, due to the high electrophilicity at the exocylic methylene carbon (see its dipolar representation in Scheme 2.11). 

Zewail-Foote, M. Hurley, L. H. Differential rates of reversibility of ecteinascidin 743-DNA covalent adducts from different sequences lead to migration to favored bonding sites. J. Am. Chem. Soc. 2001, 123, 6485-6495. 

The structural components of nucleic acids. Nucleic acids are long linear polymers of nucleotides, called polynucleotides, (a) The nucleotide consists of a five-carbon sugar (ribose in RNA or deoxyribose in DNA) covalently linked at the 5 carbon to a phosphate, and at the 1 carbon to a nitrogenous base. (b) Nucleotides are distinguished by the types of bases they contain. These are either of the two-ring purine type or of the one-ring pyrimidine type. 

C.A. Marquette, M.F. Lawrence and L.J. Blum, DNA covalent immobilization onto screen-printed electrode networks for direct label-free hybridization detection of p53 sequences, Anal. Chem., 78 (2006) 959-964. J.-M. Zen, Y.-Y. Lai, H.-H. Yang and A.S. Kumar, Multianalyte sensor for the simultaneous determination of hypoxanthine, xanthine and uric acid based on a preanodized nontronite-coated screen-printed electrode, Sens. Actuators B Chem., 84 (2002) 237-244. 

Fig. 7 Approaches for linking macromolecules to solid surfaces using biotin-strept(avidin) systems. Either biotin or streptavidin may be directly linked to a surface (e.g. Fig. 6). There are a large number of biotin derivatives with different spacer arms (e.g. Fig. 3) that may be used for immobilization. The choice of a specific biotin depends on which active group occurs on the native or derivatized surface. Attachment of strept(avidin) may be done with methods used with other proteins. Note that the deposition of a biotinylated molecules to a surface may also be used (e.g. biotinylated small molecules or large molecules like BSA) to link strept(avidin) to a surface. A DNA covalently attached at one end (3 end) can have a functional biotin at the other end that could bind to strept(avidin) or be covalently linked to streptavidin (see Fig. 4). Single-stranded DNA bound to immobilized streptavidin is available for hybridization to its complementary sequence (See Fig. 4)...

AdoMet-Dependent Methyltransferases, Chemistry of DNA, Covalent Modifications of Histone Acetyltransferases, Selective Inhibitors of Post-Translational Modifications to Regulate Protein Eunction... 

Taningher M, Parodi S, Grilli S, et al. 1991. Lack of correlation between alkaline DNA fragmentation and DNA covalent binding induced by polychloroethanes after in vivo administration. Problems related to the assessment of a carcinogenic hazard. Cancer Detect Prev 15 35-39. 

Pearlman et al. (196) built a model of a psoralen-DNA covalently crosslinked complex based on the crystal structure of a thymidine-psoralen-thymine complex, using computer graphics and molecular mechanics calcu-... 

Hingerty, B.E., Ibanez, V., Margulis, LA., Geadntov, N.E., Broyde, S., and Patel, D.j. (1992) Influence ofbenzojo] pyrene diol epoxide chirality on solution conformations of DNA covalent adducts the (-)-trons-onti-[BP]G C... 

Staker BL, Feese MD, Cushman M, et al. Structures of three classes of anticancer agents bound to the human topoisomerase l-DNA covalent complex. J Med Chem 2005 48 2336-2345. 

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