Current Pharmaceutical Biotechnology - Volume 13, Issue 14, 2012

HIF-1α is regarded as a target for drug development in several diseases such as cancer. For high throughput screening of HIF-1α-targeted drug, we need to examine the activity quantitatively. In the present study, we proposed a method where stable expression system of HIF-1α was combined with image correlation analysis. When the stable transformants were labeled with DRAQ5, we could detect Co2+-induced nuclear transl Read More

Calcium-activated photoproteins are important and useful bioluminescent reagents for detecting the calcium ion (Ca2+) in biological systems. In conjunction with photon imaging technology, they can be used to observe Ca2+-related life processes in a living cell. To develop useful applications of calcium-activated photoproteins, we need to understand the molecular basis of the bioluminescence reaction. For this purpose, this r Read More

Fluorescence correlation spectroscopy is a powerful technique for studying the structures and dynamics of living cells. Dynamic light scattering (DLS) is also used to study dynamic characteristics and it has the potential to measure cell dynamics. However, it is difficult to apply DLS to highly scattering media. In this article, we review low-coherence dynamic light scattering (LC-DLS). It strongly suppresses the influence of multi Read More

This paper describes a novel molecular design strategy for obtaining efficient two-photon absorption (TPA) materials. The most popular strategy for enhancing the TPA cross-section (σ(2)) of a molecule is to enhance its transition dipole moment. However, this strategy also red shifts the one-photon absorption (OPA) band. Consequently, molecules with large transition dipole moments typically exhibit strong OPA at visible wave Read More

Experimental method of studying viscoelasticity, a common idea to understand properties of microscopic biological soft matter systems, especially single biopolymer chains, using atomic force microscopy (AFM) with magnetically- driven cantilever is surveyed. The experimental setup of applying well-characterized excitation to the cantilever and the analysis method to derive the viscoelasticity of the system under study are briefly Read More

Atomic force microscopy (AFM) provides a novel way to understand the structure-function relationship of protein synthesis at a single-molecular level. High-resolution AFM imaging in air, liquid and vacuum allows for single DNA, RNA and proteins to be observed at the nano-scale in addition to their conformational transitions, bound states, temporal behavior, and assembly. The recent development of frequency modulation mod Read More

Inotropic agents induce changes in the contraction amplitude and frequency of cardiomyocytes (CMs). However, it is unknown how local contractions of CMs treated by inotropic agents behave spatiotemporally. In this study, the effect of isoproterenol, a positive inotropic agent, on local contractions of isolated neonatal rat CMs was explored by atomic force microscopy (AFM). We observed that changes in local contr Read More

In many signaling pathways, various factors have been isolated by molecular genetic studies and wholegenome analysis. Understanding the interactions among these factors is crucial to understanding the signaling process as a whole. Recent studies on auxin signaling in the regulation of plant growth and development have discovered primary factors interacting with each other, and elucidated a very simple pathway mod Read More

Functional analysis of carbohydrates is needed to understand the initial interface between membranes and the outer world. For this analysis we need individual protocols such as a method to modify the surfaces of nanoparticles with a variety of carbohydrates effectively and exhaustively, to synthesize an oligosaccharide on each particle's surface by chemical or enzymatic sugar elongation reaction, and to analyze the binding Read More

Mitochondria are known to be one of major organelles within a cell and to play a crucial role in many cellular functions. These organelles show the dynamic behaviors such as fusion, fission and the movement along cytoskeletal tracks. Besides mitochondria, mitochondrial DNA is also highly motile. Molecular analysis revealed that several proteins are involved in mitochondria and mitochondrial DNA dynamics. In addition to th Read More

Rheological properties of living cells play important roles in regulating their various biological functions. Therefore, measuring cell rheology is crucial for not only elucidating the relationship between the cell mechanics and functions, but also mechanical diagnosis of single cells. Atomic force microscopy (AFM) is becoming a useful technique for single cell diagnosis because it allows us to measure the rheological properti Read More

Tyrosine (Tyr) sulfation is a common posttranslational modification of secreted proteins or membrane-bound proteins that is implicated in numerous physiological and pathological processes. The Tyr sulfation modifies proteinprotein interactions involved in leukocyte adhesion, homeostasis, and receptor-mediated signaling. To data, 80 Tyrsulfated proteins have been identified. As new methodologies and bioinfor Read More

Methods for regulating peptide conformation by non-harmful light stimuli can be useful for remotely controlling cellular functions in vitro. Here, we synthesized a series of p-heteroatom-substituted azobenzenes and studied their photoisomerization properties. The trans-isomer of p-sulfur-substituted azobenzene was effectively isomerized by visible light irradiation and the cis-isomer was thermally stable at physiological te Read More

We have examined optical properties of a fluorene derivative with two positively charged substituents, 1,1'- diethyl-4,4'-(9,9-diethyl-2,7-fluorenediyl-2,1-ethanediyl)dipyridinium perchlorate (1), in water. The photoluminescence quantum yield of 1 was relatively high (35%) for use as a fluorescent probe in water. We also examined two-photon absorption (TPA) properties of 1 in methanol. The maximum value of the TPA cross-sectio Read More

Dielectric particles including living cells are trapped within focused laser beam spots, and as a result, they can be transferred by displacing the beam spots. Such the particle manipulating technique is called optical tweezers. Holographic optical tweezers (HOT) enables highly flexible and precise control of particles, introducing holography technique to them. HOT is one of the most expected techniques for investigations of Read More

Glycosphingolipids (GSLs) are present in all mammalian cell plasma membranes and intracellular membrane structures. They are especially concentrated in plasma membrane lipid domains that are specialized for cell signaling. Plasma membranes show typical structures called rafts and caveola domain structures, with large amounts of sphingolipids, cholesterol, and sphingomyelin in the cell membranes. Plasma membra Read More