Antibody News

ZMPSTE24 Mutations, Lamin A Processing & Laminopathies

Wednesday, December 28, 2011 - 10:49

ZMPSTE24 (FACE-1, CAAX prenyl protease 1 homolog) is a membrane associated zinc metalloprotease of the peptidase M48A family. It's catalytic activity can be defined as the peptide bond hydrolyzed in the sequence -C-|-A-A-X in which C is an S-isoprenylated cysteine residue, A is usually aliphatic and X is the C-terminal residue of the substrate protein, and may be any of several amino acids. It has been shown to specifically cleave the final 3 carboxy terminal residues from farnesylated prelamin A to form mature lamin A.

Mutations in ZMPSTE24 have been linked to a rare disorder known as Restrictive dermopathy (Lethal Tight Skin Contracture Syndrome).  This syndrome is characterized by intrauterine growth retardation, thin, tightly adherent translucent skin, superficial vessels, typical facial dysmorphism as well as generalized joint contractures. In a sibling study it was shown that 2 frameshift mutations that were inherited in an autosomally...

Determining DMC1's role in Homologus Recombination

Friday, December 23, 2011 - 13:57

The DMC1 gene encodes a 36.7 kDa nuclear protein involved in meiotic homologous recombination. This recombinase is functionally related to the yeast RAD51 and E. coli RecA genes. In contrast to RAD51, which functions in both mitotic and meiotic recombination, DMC1 works specifically in meiotic recombination. Despite this difference, the RAD51 and DMC1 recombinase are structurally similar but not identical in nature. This has led to the speculation that regulatory elements play a key role in the expression and function of these 2 recombinases.

Recent research show that the RAD51 associated protein 1 (RAD51AP1) binds not only to RAD51 but also to DMC1.  Using mutations and point mutations the authors showed that RAD51AP1 contains a WVPP motif that allows DMC1 to bind at this specific site, but not RAD51....

Estrogen Related Receptors Play Roles in Cancer and Neurodegeneration

Wednesday, December 21, 2011 - 11:45

By Eric Neeley

Estrogen receptors come in the form of two distinct forms, ER alpha and ER beta. These nuclear receptors are predominantly activated by the hormone 17-beta-estradiol to control transcription of genes throughout the immune, nervous, cardiovascular, and skeletal systems. The classic signaling method of these receptors involves homo- or hetero- receptor dimerization, followed by direct binding to estrogen response elements (ERE). They can also work in concert with other transcription factors, such as SP1 and Fos/Jun, to activate genes which do not contain an ERE. Estrogen receptor over-expression is extremely common...

EpiPlus Antibodies Characterized on full-length Histones using ChromataChIP Kits

Friday, December 16, 2011 - 14:56

Histone modification is known to affect transcriptional access to chromatin. Therefore, high quality histone modification specific antibodies are necessary to understand and explain the specific roles that these epigenetic modifications play in transcription regulation. Unfortunately, many of the commercially available histone modification antibodies are designed against short immunizing peptides and lack specificity to the full-length modified histone.

Epigenetics Antibodies for Epigenetics Research

In work presented at last week’s meeting of the Amercian Society for Cell Biology, researchers at 21st Century Biochemicals and...

DNMT's: An Overview of 3 DNA Methyltransferases

Thursday, December 15, 2011 - 14:33

DNA methyltransferases catalyze the transfer of the methyl group from S-andenosyl methionine (SAM) to DNA. Such methylation has wide ranging function in the cell, including organismal development and cell differentiation. In cancer, abnormal hypermethylation of gene promoter CpG islands can result in transcriptional silencing. De novo methyltransferases methylate unmethylated DNA, this occurs primarily during early embryonic development and sets the methylation pattern for that cell.  Maintenance methyltransferases methylate hemimethylated DNA and continues the methylation pattern set during development. In mammals there are three DNA methyltranferases, DNMT1, DNMT3a and DNMT3b.  All 3 are involved in DNA methylation during development, as well as coordinating the methlylation of...

Exploring the Many Roles of PGC-1 alpha

Wednesday, December 14, 2011 - 11:43

The peroxisome proliferator-activated receptor gamma, co-activator 1 (PGC-1 alpha or PPARGC1A) gene encodes a 91 kDa nuclear protein that acts as a transcriptional co-activator involved in energy metabolism. Interaction with PPAR gamma allows it to interface with numerous transcription factors such as cAMP response element binding protein (CREB) and nuclear respiratory factors (NRFs). It is believed to be a master integrator between external stimuli and cellular response, in particular mitochondrial biogenesis. It is also a major factor in muscle type determination. Recent research has shown that single-nucleotide polymorphism (SNP) mutations were associated with specific meat characteristics in pigs, which may lead to improvement in pork meat...

Glutathione and xCT: Chemoresistance in Tumor Cells

Monday, December 12, 2011 - 12:40

Glutathione, called GSH in its reduced form and GSSG or L(-)-Glutathione in its oxidized form, is an endogenous antioxidant found in most cells in the body. Glutathione's functions include detoxifying xenobiotics from the body, assisting in membrane transport, facilitating regulation of nitrogen via the nitric oxide cycle, and playing a functional role in the metabolism of iron.  Glutathione is maintained within the cell by a heterodimeric cystine/glutamate exchanger system, which exchanges intracellular glutamate for extracellular cystine.  SLC7A11 (also called xCT) and SLC3A2 (also called CD98) are the two proteins responsible for maintaining intracellular glutathione as well as non-vesicular glutamate release.

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BRCA1: Breast Cancer and Beyond

Wednesday, December 7, 2011 - 12:29

BRCA1, also known as breast cancer type 1 susceptibility protein and RING finger protein 53, belongs to a class of genes known as tumor suppressors. BRCA1 regulates cell growth and division, and is also involved in DNA repair. There have been hundreds of BRCA1 mutations identified, and many of them are associated with an increased risk of cancer.  A woman who inherits a harmful BRCA1 gene mutation is at greater risk of developing breast and/or ovarian cancer in her lifetime.  BRCA1 gene mutations can also cause cervical, uterine, pancreatic, and colon cancer in women.

Mutations to the BRCA1 gene can be...

SR-BI Antibodies: A Potential for Blocking Hepatitis C Uptake

Friday, December 2, 2011 - 10:34

Scavenger Receptor Class B Membrane 1, also known as SR-BI plays an important role in lipid metabolism. Its main function is to mediate transfer of cholesterol between the cell surface and high density lipoprotein (HDL). HDL acts as an extracellular donor and acceptor of free and esterified Cholesterol. SR-BI also acts as a receptor for other ligands including lipoproteins, apoptotic cells and phospholipids. SR-BI is widely expressed and exists in high abundance in caveolae, which is highly enriched with cholesterol. SR-BI expression has been shown to increase cholesterol influx and efflux from HDL.

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Carbonic Anhydrase IX and Hypoxic Response: A Path to Tumors

Wednesday, November 30, 2011 - 10:52

Carbonic Anhydrase IX (CA-IX) is an enzyme that is induced under hypoxic conditions. This enzyme is rarely present in normal cells and is responsible for controlling tumor pH. CA-IX is a transmembrane glycoprotein of the zinc metalloenzyme family. This family displays 15 isoforms in human tissues. Carbonic Anhydrase IX functions to convert carbonic acid present in hypoxic cells into a biocarbonate and a proton. Due to the hypoxic conditions found in many tumors CA-IX has become a marker of hypoxia and expression has been associated with several tumors such as lung, brain, colorectal, ovarian, renal, breast, and cervical to name a few.

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Analyzing LC3 in Western blot

Monday, November 28, 2011 - 10:13

Microtubule-associated protein light chain 3 (LC3) is considered one of the definitive markers of autophagy, and its use is widespread in labs throughout the world. Despite its popularity, there are several considerations when employing LC3 antibodies in immunoassays, and in particular Western blots.

LC3 is expressed as a propeptide, and is subsequently cleaved to form LC3-I.  Initiation of autophagy causes the conversion of LC3-I to LC3-II via the addition of a phosphatidylethanolamine (PE) group to the C terminus.  The PE group increases the rate of band migration in an SDS-PAGE gel, likely due to its hydrophobic nature; this modification commonly manifests as the appearance of a doublet in a Western blot.  The lipophilic character of the PE group also facilitates the insertion of LC3-II into the membranes of autophagosomes, and as a result LC3-II is degraded as autophagosomes are turned...

Sox2 and Oct4: Roles in Embryonic Stem Cell Pluripotency

Thursday, November 10, 2011 - 14:35

Embryonic stem (ES) cells are cells derived from the inner cell mass of the blastocyst, an early-stage embryo. ES cells are distinguished from other cells due to their pluripotency, which is the ability to differentiate into any different type of cell in the body, and also their capability of propagating indefinitely. These two factors make embryonic stem cells valuable tools in the scientific community, especially in regenerative medicine.

Sox2 and Oct4 are well known transcriptional activators that play a crucial role in the regulation of embryonic stem cell pluripotency. When Oct4 and Sox2 expression is knocked down, embryonic stem cells lose the ability to maintain their pluripotency. Research using gene-knockout experiments has shown the importance of Oct4 and Sox2 in...

Beta Actin and GAPDH: The Importance of Loading Controls

Wednesday, November 9, 2011 - 13:43

Western blotting is an essential technique to probe protein expression in complex cell or tissue lysates. To accurately determine protein expression and interpret Western blot results, it is important to use loading controls. A loading control antibody helps determine if samples have been loaded equally across all wells and confirms effective protein transfer during the western blot protocol. When considering a loading control for your experiment, it is important to choose a protein that does not have a similar molecular weight to your target of interest. Additionally, the loading control protein should demonstrate ubiquitous expression. The most popular loading control targets include beta-Actin and GAPDH.

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Potential breakthrough in HIV research means therapeutic HIV antibodies may be coming soon.

Friday, November 4, 2011 - 10:32

Research antibodies have long been used to advance HIV/Aids research, however researchers at the California Institute of Technology have recently published a study [PMID: 22033520] developing a new antibody that may someday be used clinically to neutralize HIV. Beginning with a naturally occurring antibody (NIH45-46) purified from HIV positive patients, the researchers modified the antibody using a technique called structure-based rational design. The resulting antibody (NIH45-46G54W) showed some promising new characteristics, including improved specificity and binding against the host receptor (CD4) for many HIV subtypes. This binding neutralizes the HIV by effectively blocking access to the receptor and therefore stopping the proliferation of the virus.

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Epitope Tagging: From His to OLLAS

Tuesday, November 1, 2011 - 11:03

Epitope tagging is a procedure that inserts a short amino acid sequence into a protein within an expression vector via genetic engineering. Antibodies that recognize the tag can then be used to detect the protein when no antibody to the target protein exists or when the target protein shows low immunogenicity.  Such tags can be inserted at the C-terminus, N-terminus or even within the protein itself.  Terminal insertion is preferred as internal tags may alter protein function or become buried within the tertiary structure of the protein. Initially tags were used to facilitate purification (e.g. 6xHis®, GST), however they are now used in Western blots, IHC, immunoprecipitation and flow cytometry.

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Amyloid beta and Methionine Sulfoxide Related to Abeta 42 Antibody and Abeta 40 Antibody

Thursday, October 27, 2011 - 12:03

By Eric Neeley

Alzheimer's disease is a devastating neurodegenerative illness characterized by the formation of plaques, tangles, and eventually synaptic loss. Amyloid beta (Aβ) is the processed form of the Amyloid precursor protein (APP), and whose aggregation eventually forms the amyloid plaques of the disease. APP is cleaved by alpha, beta, and gamma secretases to form numerous peptide isoforms of various lengths, but most common are 40 and 42, which are created by the later of the secretases. Both forms of the peptide are important for research, as is the need for tools that can differentiate between the two. Although Aβ40 is more...

Marking the Autophagosome: the LC3 Antibody

Thursday, October 20, 2011 - 10:23

MAP1LC3 (shortened to LC3 in our antibody catalog) is one of four mammalian homologues of autophagy-related protein 8 (Atg8). It has been identified as a light chain subunit of the microtubule-associated proteins MAP1A/MAP1B. A modified form of LC3, LC3-II, has been identified as a marker for the autophagosomal membrane in mammals.

To date, LC3 is the only known reliable autophagosome marker. Three transcript variants (LC3A, B and C) have been identified in mammals, which undergo post-translational modification during autophagy. LC3 immunoblot assays generally reveal two bands: LC3-I, (the cytosolic form,) and LC3-II (the membrane-bound, lipidated form.)

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MMP Antibodies Earn a Floral Tribute as New VDA Therapy is Revealed

Tuesday, October 18, 2011 - 09:27

The main function of the matrix metalloproteinase (MMP) family was originally thought to be restricted to degradation of extracellular matrix (ECM) proteins. However, studies with their antibodies have identified several other functions. We at Novus Biologicals have an extensive range of MMP antibodies for research.

The MMP family is divided into two subgroups: soluble MMPs, and membrane-type MMPs (MT-MMPs). Studies using transmembrane MMP antibodies have shown a pivotal role in tumourigenesis, with expression raised in many types of cancer.

Work with MMP2 antibodies identified the enzyme as a possible early tumour marker. MT1-MMP (also called MMP-14) activates MMP2; antibody experiments have suggested this interaction may be involved in tumour invasion. Elevated expression of MT1-MMP has been strongly linked to tumour cell growth, differentiation and migration, leading to...

The GAPDH Antibody in Western blot Assays

Thursday, October 13, 2011 - 10:19

The loading controls on our antibody database are widely used in gel electrophoresis and Western blotting studies. Products like the GAPDH antibody detect "housekeeping" proteins which are abundantly distributed in cells. This makes them useful for checking the even loading of gel samples, and the even transfer of proteins at the blotting stage. They also serve a purpose in quality control, by verifying reagents are working correctly, and in the standardization of experimental results.

All the loading control proteins on our antibody database are highly expressed throughout the eukaryotic cellular system, though some are localized to one particular area (e.g. COX IV is specific to the inner mitochondrial membrane.) Loading controls may be subcellular fractions, or entire proteins such as GAPDH.

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The CD11b Antibody: A Marker for Microglial Cells

Monday, October 10, 2011 - 10:29

Microglia are the resident macrophages of the central nervous system, and the first line of immune defense. Pioneering antibody research in the 1990's identified the Integrin beta 2 protein (also called ITGB2, complement receptor 3, CR3, CD18, and Mac-1) as one of the key proteins in the recruitment of microglial cells. The ITGB2 subunit A is commonly called CD11b, and antibodies to this subunit are widely used as microglial markers. An alternative name for CD11b is Integrin alpha M, or ITGAM. It associates non-covalently with CD18 to form the CR3 integrin. CR3 is highly expressed on leukocytes of the innate immune system, including neutrophils, monocytes and NK cells, but less so on macrophages. Antibody studies have shown CR3 to mediate inflammation by regulating leukocyte migration and adhesion, and to be...

HIF-2 alpha Antibody Throws New Light on EPO Dilemma

Thursday, October 6, 2011 - 13:43

The HIF family are heterodimeric, oxygen-sensitive transcription factors comprising an alpha and beta subunit which are normally dissociated in normoxic conditions. Our antibody catalog contains products targeting all the Hypoxia Inducible Factor isoforms which have been identified in mammalian cells. These include HIF-2 alpha antibody reagents targeting both the entire protein and specific epitopes.

HIF is an alpha/beta heterodimer that is activated by hypoxic conditions, binding hypoxia response elements (HREs) at target gene loci. The first HIF isoform to be discovered was HIF-1, which in 1995 was identified as a transcription factor for the EPO (erythropoietin) gene in renal fibroblasts. Further research showed the alpha subunit to be located in the cytosol, being rapidly degraded in...

HIF Antibodies: Beyond HIF-1 alpha

Tuesday, October 4, 2011 - 15:42

The hypoxia inducible factors are a family of heterodimeric transcription factors which are activated in response to lowered oxygen levels, or hypoxia. Although it may seem that HIF-1 alpha receives all the attention, other HIF antibodies, such as the HIF-2 alpha and HIF-1 beta antibody, are frequently used in clinical research as well. The three human hypoxia inducible factors HIF-1, 2 and 3 are transcriptional complexes consisting of an alpha and beta subunit. Each of the six subunits is encoded by a different gene. In normoxic conditions the subunits are non-dimeric, combining to form a functional complex when triggered by hypoxia. The alpha subunit is unique to the hypoxic response and rendered inactive in the cytosol in normoxic conditions. However, HIF-1 beta antibody research has shown...

Who Needs Antibodies for Tubulin Modifications?

Thursday, September 29, 2011 - 11:11

Tubulin is a heterodimeric complex composed of alpha and beta subunits. Just like histones, tubulin can undergo post-translational modification, to affect cellular function. Novus Biologicals offers a large database of modified Tubulin antibody products.

Tubulin is the key building block of microtubules, found in practically all eukaryotic cells. The microtubules are essential to structure and mobility, being involved in mitosis, meiosis, flagella movement, organelle mobility, intracellular transport and cytoskeletal function. The detection, isolation and study of microtubular proteins, through alpha and beta Tubulin antibody research, are essential to the understanding of microtubule function.

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An Unlikely Pairing: The SOX2 Antibody and Breast Cancer

Monday, September 26, 2011 - 12:05

SOX2 encodes a member of the SOX (SRY-related HMG-box) family of transcription factors, which play a vital role in embryonic development. SOX2 antibody research has identified Sox2 as a key transcription factor in pluripotent stem cells. We at Novus Biologicals offer a number of top quality SOX2 products in our stem cell antibody catalog.

Embryonic stem cell research has shown NANOG, SOX2 and OCT3/4 to form the core of the self-renewal transcription network in pluripotent ESCs, sharing transcription of numerous genes. Selective down regulation of these genes induces differentiation and halts pluripotency. In recent experiments, a pluripotent stem cell state was achieved in adult somatic cells, by forced expression of NANOG, SOX2, OCT4 and...

Survivin Sandwich ELISA: There's a Kit for That

Thursday, September 22, 2011 - 11:53

The Survivin antibody is widely used in apoptosis studies, and as a cellular marker. Today, biochemists have a wide range of Survivin antibody products to choose from, suitable for use in Western Blot, Chromatin Immunoprecipitation (ChIP), Immunofluorescence and similar assays.

ELISA (Enzyme-linked immunosorbent assay) is a popular tool in Survivin antibody research. In simple terms, ELISA involves binding of an antigen to an enzyme-linked antibody, which must be highly specific. Various formats of this basic technique have been developed, the most powerful of which is the Sandwich ELISA assay. Sandwich ELISA is dependent upon antigens with at least two binding sites, as it uses both a capture and a detection antibody, between which the sample is “sandwiched.” This has several benefits over standard ELISA, including increased sensitivity and the fact samples do not need to be purified prior to analysis...

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