细胞技术

The synthesis, characterization, and use of fluorescently labeled lipid probes to follow transport in living cells at a microscopic level have greatly expanded our knowledge of intracellular lipid trafficking. Although lipids containing a number of covalently attached fluoro ...

The first measurement of the transmembrane diffusion of phospholipids in membranes was carried out by Kornberg and McConnell in 1971 (1). These authors sonicated an aqueous suspension of egg lecithin mixed with a small percentage of a spin-labeled phosphatidylcholine. The spin-labe ...

This chapter details the procedural and conceptual issues that underpin the localization of high-affinity amino acid transporters by immunocytochemistry, with particular reference to the mammalian nervous system. Defining a role for transporters in any individual tissue of ...

Transmembrane ion channels, or, more broadly, membrane transporters, are the subject of electrophysiology that leads us to the understanding of nearly every event of biological activities. Since the introduction of patch clamp concepts and techniques (1,2), transmembrane ion chan ...

One way to characterize structure and function in transporters is chemical. The analysis specifies the three-dimensional structure of the transporter and changes in structure that occur during the transport cycle. It can ignore intermediate steps in the cycle by showing only reactan ...

During oogenesis, Xenopus oocytes accumulate large amounts of storage proteins that—after fertilization—provide the developing embryo with building blocks and energy metabolites. The size of the fully developed oocyte (diameter, 1.2 mm) is largely governed by the stored amounts ...

Structural data are critical for an understanding of how membrane transport systems function; unfortunately, high-resolution crystal structures for these systems are rare, primarily because of difficulties in crystallization. One alternative approach to the structure pr ...

Intracellular pH regulation is critical for most cellular processes, including cell volume regulation, vesicle trafficking, cellular metabolism, cell membrane polarity, muscular contraction, and cytoskeletal interactions (1–6). Changes of intracellular pH (pHi) affect ...

Not only do membrane proteins represent a substantial fraction of the information in a genome, but also they are responsible for many essential biological functions, some of which are unique (e.g., as membrane transporters). As a result, some mutations in genes for membrane proteins cause human ...

In silico methods are increasingly being used to address problems of biological significance. In the realm of structural biology, computational approaches have been applied to modeling the three-dimensional (3D) conformation of proteins and other molecules whose structures ha ...

Knowledge of membrane transporter molecular structures is crucial for obtaining a detailed understanding of the mechanism by which these proteins shuttle their cargo across a biological membrane. Unfortunately, ascertaining complete structures of these transporters cur ...

Confocal microscopy has become a widely used method in the study of plasma membrane proteins. A Medline search for the terms “plasma membrane” and “confocal” returns over 1300 references since 1966. Of these, over 1000 references appeared in the past 5 yr, and over 500 in the past 2 yr. The recent widespre ...

Membrane transporters play crucial roles in fundamental cellular functioning and normal physiological processes of archaebacteria, prokaryotes, and eukaryotes (1). Transporters are proteins that span the lipid bilayer and form a transmembrane channel lined with hydrophi ...

Transport systems are essential to every living cell. They (1) allow the entry of all essential nutrients into the cell and its compartments, (2) regulate the cytoplasmic concentrations of metabolites by excretion mechanisms, (3) provide physiological cellular concentrations of io ...

Neurotransmitter transporters play a critical role in numerous biological functions. Disruption of transporter function can lead to perturbations in many of these physiological processes. An example of this is the plasma membrane dopamine transporter (DAT). Genetic deletion of ...

With a history of less than 30 years, bioinformatics is a rapidly growing area that applies computational approaches to solve biological problems. Similar to the composition of the word itself, “bioinformatics” is an independent field developed from the union of computer science and mole ...

The newly developed microarray technology has made it possible to simultaneously monitor the expression of thousands of genes under specific physiological and pathological conditions. An array contains thousands of nucleic acid probes with known sequences. When the labeled tar ...

Parkinson’s disease (PD) is a progressive neurodegenerative disease as a result of a selective degeneration of dopamine neurons in the substantia nigra. The selective loss of dopamine neurons in Parkinson’s disease is thought to involve altered expression or function of the plasma memb ...

One of the major goals in membrane transporter research is to understand how transporter proteins work at the molecular level. Ideally, this research would be carried out with a detailed knowledge of the three-dimensional structure of the protein. However, in the absence of protein crystals ...

Fluorescence spectroscopic techniques have been widely applied to the study of soluble proteins over the past 20 yr, and they are being increasingly applied to membrane proteins, including membrane transporters. Some advantages of fluorescence approaches include high sensiti ...