细胞功能测定

It is now recognized that mammalian mitochondrial DNA forms a higher structure called the nucleoid, corresponding to the nucleosome of nuclear DNA. Mitochondrial transcription factor A (TFAM), which was cloned as a transcription factor for mitochondrial DNA, is essential for the main ...

Defects in mtDNA replication are the principle cause of severe, heritable metabolic disorders classified as mitochondrial diseases. In vitro analysis of the biochemical mechanisms of mtDNA replication has proven to be a powerful tool for understanding the origins of mitochondrial ...

Tubulin, the microtubule building-block, is the target of numerous small molecule compounds that interfere with microtubule dynamics. Several of these ligands are in clinical use as antitumor drugs. There have been numerous studies on these molecules, with two main objectives: to dete ...

The knowledge of the thermodynamics and kinetics of drug-microtubule interaction is essential to understand the structure/affinity relationship of a given ligand family. When a ligand does not show an appropriate signal change (absorbance or fluorescence) upon binding, the exte ...

Vinca alkaloids play a vital role in chemotherapy protocols for a wide range of hematological and solid tumors. Studies of drug interactions with the drug target, tubulin or microtubules, have helped us to understand the cytotoxic and toxic effects. We present here in vivo and in vitro methods for s ...

Drugs that affect microtubule dynamics are among the most effective anticancer agents in routine clinical use. The standard assay for antimicrotubule agents observes the ability of a particular substance to affect in vitro microtubule assembly. We have modified these procedures so t ...

Taxol, the first microtubule stabilizer identified, is one of the most important new anticancer drugs to be brought to the clinic in the past 20 yr. The clinical success of Taxol? led to the development of a second-generation taxane, docetaxel (Taxotere™), and multiple third-generation taxane d ...

This method is a modification of the initial procedure employed to purify tubulin from mammalian brain. It consists of tissue homogenization, elimination of cell membranes, ammonium sulfate fractionation, and batch anion exchange, followed by selective precipitation with magn ...

Microtubule-binding proteins are conveniently divided into two large groups: MAPs (microtubule-associated proteins), which can stabilize, anchor, and/or nucleate microtubules, and motors, which use the energy of ATP hydrolysis for a variety of functions, including microtub ...

Tubulin heterogeneity within eukaryotic cells is generated by differential gene expression and posttranslational modification of α- and β-tubulin gene products, either as heterodimers or when polymerized into microtubules. The characterization of posttranslational ...

Cytoplasmic microtubules are noncovalent polymers of the protein tubulin. In the cells, the main function of microtubules is to provide tracks for organelle transport. Two experimental approaches based on fluorescence microscopy are commonly used to examine organization of mic ...

Although the structures of individual proteins and moderately sized complexes of proteins may be investigated by X-ray crystallography, the interaction between a long polymer, such as a microtubule, and other protein molecules, such as the motor domain of kinesin, need to be studied by elec ...

Stathmin is an important phosphorylation-controlled regulator of microtubule dynamics and plays a crucial role in cell division and cell proliferation. In its non-phosphorylated form, stathmin is the protein that interacts the most tightly with tubulin, in a 2:1 tubulin-stathmin ( ...

Numerous comparisons have shown that confocal imaging of fluorescently labeled samples has superior image clarity compared to traditional epifluorescence microscopy, especially when imaging through thick specimens. Nevertheless, one limitation of confocal microsc ...

In this article, the author describes the needed instrumentation and the methods to be followed for the observation and measurement of the birefringence of single and bundled microtubules and of their ordered arrays using a polarizing microscope. As instruments, the traditional pola ...

Nitric oxide (NO) is a small, labile molecule that plays a key role as an intercellular and intracellular messenger. Interest in the mechanisms by which NO exerts its effects has increased tremendously along with the vast experimental evidence implicating NO in a variety of physiological and ...

There now exists a bewildering array of biological processes in which free radicals have been implicated (1), and we assume that enzymes and structural proteins may be attacked whenever free radicals are generated. As a consequence, oxidative modification of proteins may occur in a variety of ...

Lipid peroxidation has been associated with important pathophysiological events in a variety of diseases, drug toxicities, and traumatic or ischemic injuries. It has been postulated that free radicals and aldehydes generated during this process may be responsible for these effec ...

Normal oxidative metabolism leads to the generation of reactive oxygen species (ROS), in particular, superoxide anion (O2−), and its dismutation product hydrogen peroxide (H2O2), which may escape from the electron-transport chain (1. In addition, oxidative stress may be generated th ...

Molecular oxygen is an excellent acceptor of electrons and is therefore employed by nature for a wide variety of highly important biochemical reactions. The chemical reactivity of oxygen, however, also leads to the formation of oxygen radicals as by-products of metabolism. These radica ...