遗传学实验技术

In addition to binding affinity, the on and off rates of drug-DNA interactions are important in determining the biological activities of a drug For example, the rate of dissociation of a drug from DNA has been shown to be related to its pharmacological activities (1). Various techniques have been em ...

Calorimetric techniques can be used to measure the heat effects accompanying a drug-DNA interaction (1–3); in principle, one can calculate from these measurements both (4) the affinity (ΔG) and enthalpy change (ΔH) for the process. There are, however, many sites on the DNA lattice for interacti ...

Footprinting analysis has been used to identify the binding sites of drugs and other ligands bound to DNA molecules (see Chapter 1) (1–3). It is particularly useful for equilibrium binding drugs or ligands that leave no record of their residence position on DNA In the footprinting procedure, the l ...

The uranyl(IV) ion (UO2 2+) binds strongly to the phosphates of DNA and, upon irradiation with long wavelength ultraviolet light, the proximal deoxyn-boses are oxidized by the photochemically excited state of the uranyl1 ion, a very strong oxidant (1). Thus the uranyl ion is an efficient DNA photoc ...

Chemical probing of nucleic acids is a powerful and versatile approach to the detection and analysis of the structural and functional complexity of nucleic acids (1). Secondary structures of native DNA and RNA as well as ligandinduced changes in conformation can be probed by the use of a variety of c ...

The existence of cell-type specific promoter and enhancer elements has been known for several years. However, the mechanisms responsible for the remarkable specificity of such elements, in comparison to the ubiquitously active promoters and enhancers of “housekeeping” genes and D ...

There are a number of proteins involved in DNA replication, recombination, or repair that bind stoichiometrically to single DNA strands irrespective of the nucleotide sequence, and some of these proteins also bind to single-stranded RNA. Some of the best known examples are the ssb protein of E ...

The scanning transmission electron microscope (STEM) at Brookhaven National Laboratorundefined (BNL) is nearly unique in its ability not only to image isolated unstained and unshadowed biological molecules but also to obtain quantitative information about them such as their oligomeric ...

DNA-protein interactions are instrumental in the replication, repair, recombination, and expression of genetic information. Their study under physiological conditions requires rapid methods that do not cause extensive cell damage. Among the available techniques, crossl ...

Despite the widespread use of chemotherapeutic drugs in the treatment of various malignancies, in many cases the mechanism of tumor cell kill remains unknown There is, however, much evidence that suggests that DNA is the major cellular target for many of the agents in current clmical use. A number of ...

Although there have been many studies on the interaction of DNA-binding agents with both natural and synthetic nucleic acids, these have almost exclusively concerned their binding to naked DNA. In contrast, cellular DNA is packed into chromatm, generating higher order structures, which ...

Many agents used in the treatment of cancer are bifunctional in nature and are therefore able to crosslink cellular macromolecules. Despite these nonspecific reaction mechanisms, DNA appears to be the most important cellular target for many of these anticancer agents. The formation of D ...

The authors have devised a simple method for the detection of drug–DNA interaction and sequence selectivity in vitro (1).The method is based on the inhibition or termination of bacterial DNA polymerase(s) when it encounters modified DNA sequences. The DNA polymerase inhibition assay (PI ...

There are now approx 50 registered anticancer drugs that are in routine clinical use as chemotherapeutic agents (1–3). Of these, over half are known to interact with DNA, either by intercalation (e.g., doxorubicin, mitoxantrone), groove binding (e.g., distamycin), formation of adducts or cro ...

RNA interference (RNAi) is an important pathway to combat virus infections in insects and plants. Hallmarks of antiviral RNAi in these organisms are: (1) an increase in virus replication after inactivation of major actors in the RNAi pathway, (2) production of virus-derived small interfer ...

MicroRNAs (miRNAs) play an essential role in the regulation of eukaryotic gene expression. Recent studies demonstrate that miRNAs can also strongly affect the replication of pathogenic viruses. For example, cellular miRNAs can target and repress the expression of viral mRNAs, but the ...

Since 2004, more than 200 microRNAs (miRNAs) have been discovered in double-stranded DNA viruses, mainly herpesviruses and polyomaviruses (Nucleic Acids Res 32:D109–D111, 2004). miRNAs are short 22  �  3 nt RNA molecules that posttranscriptionally regulate gene expression by binding ...

RNA interference (RNAi) refers to the conserved sequence-specific degradation of message RNA mediated by small interfering (si)RNA duplexes 21–25 nucleotides in length. Given the ability to specifically silence any gene of interest, siRNAs offers several advantages over conven ...

Chemically synthesized siRNAs are widely used for gene silencing. For in vitro applications, stability, delivery, and immunological issues are rarely problematic, but for in vivo applications the situation is different. Limited stability, undesirable pharmacokinetic beha ...

Mammalian host cells and their viral pathogens express and make use of short noncoding RNA molecules to control the infectious cycle. In order to understand their physiological role, it is necessary to develop tools for detection and quantification of these molecules. Here, we present a simp ...