Far-eastern blot

Last updated

The far-eastern blot, or far-eastern blotting, is a technique for the analysis of lipids separated by high-performance thin layer chromatography (HPTLC). When executing the technique, lipids are transferred from HPTLC plates to a PVDF membrane for further analysis, for example by enzymatic or ligand binding assays [1] and mass spectrometry. [2] It was developed in 1994 by Taki and colleagues [1] at the Tokyo Medical and Dental University, Japan.

Contents

Analysis

Cholesterol, glycerophospholipids and sphingolipids are major constituents of the cell membrane and in certain cases function as second messengers in cell proliferation, apoptosis and cell adhesion in inflammation and tumor metastasis. Far-eastern blot was established as a method for transferring lipids from an HPTLC plate to a polyvinylidene difluoride (PVDF) membrane within a minute. Applications of this with other methods have been studied. Far-eastern blotting allows for the purification of glycosphingolipids and phospholipids, structural analysis of lipids in conjunction with direct mass spectrometry, binding studies using various ligands such as antibodies, lectins, bacterium, viruses, and toxins, and enzyme reaction on membranes.

Far-eastern blot is adaptable to the analysis of lipids as well as metabolites of drugs and natural compounds from plants and environmental hormones. [1]

Etymology

The name is a dual reference to eastern blot and the geographical concept of the Far East (which includes Japan).

Related Research Articles

Molecular biology Branch of biology dealing with biological activitys molecular basis

Molecular biology is the branch of biology that concerns the molecular basis of biological activity in and between cells, including molecular synthesis, modification, mechanisms and interactions.

Northern blot molecular biology technique

The northern blot, or RNA blot, is a technique used in molecular biology research to study gene expression by detection of RNA in a sample.

Western blot analytical technique used in molecular biology

The western blot, or western blotting, is a widely used analytical technique in molecular biology and immunogenetics to detect specific proteins in a sample of tissue homogenate or extract.

A blot, in molecular biology and genetics, is a method of transferring proteins, DNA or RNA onto a carrier. In many instances, this is done after a gel electrophoresis, transferring the molecules from the gel onto the blotting membrane, and other times adding the samples directly onto the membrane. After the blotting, the transferred proteins, DNA or RNA are then visualized by colorant staining, autoradiographic visualization of radiolabelled molecules, or specific labelling of some proteins or nucleic acids. The latter is done with antibodies or hybridization probes that bind only to some molecules of the blot and have an enzyme joined to them. After proper washing, this enzymatic activity is visualized by incubation with proper reactive, rendering either a colored deposit on the blot or a chemiluminescent reaction which is registered by photographic film.

Lipidomics

Lipidomics is the large-scale study of pathways and networks of cellular lipids in biological systems The word "lipidome" is used to describe the complete lipid profile within a cell, tissue, organism, or ecosystem and is a subset of the "metabolome" which also includes the three other major classes of biological molecules: proteins/amino-acids, sugars and nucleic acids. Lipidomics is a relatively recent research field that has been driven by rapid advances in technologies such as mass spectrometry (MS), nuclear magnetic resonance (NMR) spectroscopy, fluorescence spectroscopy, dual polarisation interferometry and computational methods, coupled with the recognition of the role of lipids in many metabolic diseases such as obesity, atherosclerosis, stroke, hypertension and diabetes. This rapidly expanding field complements the huge progress made in genomics and proteomics, all of which constitute the family of systems biology.

Fas ligand protein-coding gene in the species Homo sapiens

Fas ligand is a type-II transmembrane protein that belongs to the tumor necrosis factor (TNF) family. Its binding with its receptor induces apoptosis. Fas ligand/receptor interactions play an important role in the regulation of the immune system and the progression of cancer.

P-selectin Cell adhesion molecule (CAM) on the surfaces of activated endothelial cells, which line the inner surface of blood vessels, and activated platelets

P-selectin is a protein that in humans is encoded by the SELP gene.

Dot blot

A dot blot is a technique in molecular biology used to detect proteins. It represents a simplification of the western blot method, with the exception that the proteins to be detected are not first separated by electrophoresis. Instead, the sample is applied directly on a membrane in a single spot, and the blotting procedure is performed.

Neuroproteomics is the study of the protein complexes and species that make up the nervous system. These proteins interact to make the neurons connect in such a way to create the intricacies that nervous system is known for. Neuroproteomics is a complex field that has a long way to go in terms of profiling the entire neuronal proteome. It is a relatively recent field that has many applications in therapy and science. So far, only small subsets of the neuronal proteome have been mapped, and then only when applied to the proteins involved in the synapse.

Sulfatide, also known as 3-O-sulfogalactosylceramide, SM4, or sulfated galactocerebroside, is a class of sulfolipids, specifically a class of sulfoglycolipids, which are glycolipids that contain a sulfate group. Sulfatide is synthesized primarily starting in the endoplasmic reticulum and ending in the Golgi apparatus where ceramide is converted to galactocerebroside and later sulfated to make sulfatide. Of all of the galactolipids that are found in the myelin sheath, one fifth of them are sulfatide. Sulfatide is primarily found on the extracellular leaflet of the myelin plasma membrane produced by the oligodendrocytes in the central nervous system and in the Schwann cells in the peripheral nervous system. However, sulfatide is also present on the extracellular leaflet of the plasma membrane of many cells in eukaryotic organisms.

Exosome (vesicle)

Exosomes are membrane bound extracellular vesicles (EVs) that are produced in the endosomal compartment of most eukaryotic cells. The multivesicular body (MVB) is an endosome defined by intraluminal vesicles (ILVs) that bud inward into the endosomal lumen. If the MVB fuses with the cell surface, these ILVs are released as exosomes. In multicellular organisms, exosomes and other EVs are present in tissues and can also be found in biological fluids including blood, urine, and cerebrospinal fluid. They are also released in vitro by cultured cells into their growth medium. Since the size of exosomes is limited by that of the parent MVB, exosomes are generally thought to be smaller than most other EVs, from about 30 to 150 nanometres (nm) in diameter: around the same size as many lipoproteins but much smaller than cells. Compared with EVs in general, it is unclear whether exosomes have unique characteristics or functions or can be separated or distinguished effectively from other EVs. EVs including exosomes carry markers of cells of origin and have specialized functions in physiological processes, from coagulation and intercellular signalling to waste management. Consequently, there is a growing interest in clinical applications of EVs as biomarkers and therapies alike, prompting establishment of an International Society for Extracellular Vesicles (ISEV) and a scientific journal devoted to EVs, the Journal of Extracellular Vesicles.

Electroblotting

Electroblotting is a method in molecular biology/biochemistry/immunogenetics to transfer proteins or nucleic acids onto a membrane by using PVDF or nitrocellulose, after gel electrophoresis. The protein or nucleic acid can then be further analyzed using probes such as specific antibodies, ligands like lectins, or stains. This method can be used with all polyacrylamide and agarose gels. An alternative technique for transferring proteins from a gel is capillary blotting.

Microvesicles An extracellular vesicle released from the plasma membrane and ranging in size from about 100 nm to 1000 nm.

Microvesicles are a type of extracellular vesicle (EV) that are released from the cell membrane. In multicellular organisms, microvesicles and other EVs are found both in tissues and in many types of body fluids. Delimited by a phospholipid bilayer, microvesicles can be as small as the smallest EVs or as large as 1000 nm. They are considered to be larger, on average, than intracellularly-generated EVs known as exosomes. Microvesicles play a role in intercellular communication and can transport molecules such as mRNA, miRNA, and proteins between cells.

Sigma-2 receptor protein-coding gene in the species Homo sapiens

The sigma-2 receptor (σ2R) is a sigma receptor subtype that has attracted attention due to its involvement in diseases such as cancer and neurological diseases. It is currently under investigation for its potential diagnostic and therapeutic uses.

T-cadherin protein-coding gene in the species Homo sapiens

T-cadherin also known as cadherin 13, H-cadherin (heart) (CDH13) is a unique member of cadherin superfamily because it lacks the transmembrane and cytoplasmic domains and is anchored to the cells membrane through the GPI anchor. Classical cadherins are necessary for cell–cell contacts, dynamic regulation of morphogenetic processes in embryos and tissue integrity in adult organism. Cadherins function as membrane receptors mediating outside-in signals, activating small GTPases and beta-catenin/Wnt pathway, and resulting in dynamic cytoskeleton reorganization and changes in the phenotype.

ALCAM protein-coding gene in the species Homo sapiens

CD166 antigen is a 100-105 kD typeI transmembrane glycoprotein that is a member of the immunoglobulin superfamily of proteins. In humans it is encoded by the ALCAM gene. It is also called CD166, MEMD, SC-1/DM-GRASP/BEN in the chicken, and KG-CAM in the rat.

The eastern blot, or eastern blotting, is a biochemical technique used to analyze protein post-translational modifications (PTM) including the addition of lipids, phosphates, and glycoconjugates. It is most often used to detect carbohydrate epitopes. Thus, eastern blot can be considered an extension of the biochemical technique of western blot. Multiple techniques have been described by the term "eastern blot(ting)", most use prospo protein blotted from SDS-PAGE gel on to a PVDF or nitrocellulose membrane. Transferred proteins are analyzed for post-translational modifications using probes that may detect lipids, carbohydrate, phosphorylation or any other protein modification. Eastern blotting should be used to refer to methods that detect their targets through specific interaction of the PTM and the probe, distinguishing them from a standard far-western blot. In principle, eastern blotting is similar to lectin blotting.

A thermal shift assay (TSA) measures changes in the thermal denaturation temperature and hence stability of a protein under varying conditions such as variations in drug concentration, buffer pH or ionic strength, redox potential, or sequence mutation. The most common method for measuring protein thermal shifts is differential scanning fluorimetry (DSF) or thermofluor, which utilizes specialized fluorogenic dyes.

A Ligand binding assay (LBA) is an assay, or an analytic procedure, which relies on the binding of ligand molecules to receptors, antibodies or other macromolecules. A detection method is used to determine the presence and extent of the ligand-receptor complexes formed, and this is usually determined electrochemically or through a fluorescence detection method. This type of analytic test can be used to test for the presence of target molecules in a sample that are known to bind to the receptor.

The northwestern blot, also known as the northwestern assay, is a hybrid analytical technique of the western blot and the northern blot, and is used in molecular biology to detect interactions between RNA and proteins. A related technique, the western blot, is used to detect a protein of interest that involves transferring proteins that are separated by gel electrophoresis onto a nitrocellulose membrane. A colored precipitate clusters along the band on the membrane containing a particular target protein. A northern blot is a similar analytical technique that, instead of detecting a protein of interest, is used to study gene expression by detection of RNA on a similar membrane. The northwestern blot combines the two techniques, and specifically involves the identification of labeled RNA that interact with proteins that are immobilized on a similar nitrocellulose membrane.

References

  1. 1 2 3 D. Ishikawa & T. Taki (1998), "Micro-scale analysis of lipids by far-eastern blot (TLC blot)", Nihon Yukagaku Kaishi, 47 (10): 963–970, doi: 10.5650/jos1996.47.963
  2. Hamasaki H, Aoyagi M, Kasama T, Handa S, Hirakawa K, Taki T (January 1999). "GT1b in human metastatic brain tumors: GT1b as a brain metastasis-associated ganglioside". Biochim. Biophys. Acta. 1437 (1): 93–9. doi:10.1016/S1388-1981(98)00003-1. PMID   9931455.