Hyaluronic acid (also called HA or Hyaluronan) is a glycosaminoglycan with elevated viscosity, enabling tissues (eye, skin, joint and synovial fluid…) to resist to physical and mechanical constraints (torsion, flexion…). Over time, when HA production declines, tissues progressively lose these tensile properties, leading to wrinkles and fold, weak re-epithelisation and age-related troubles. But HA is also involved in many other chronic and cancer-related diseases. In this post, we’ll review one of the most popular HA quantification assays (ELISA test), known to be highly sensitive and robust, appreciated by researchers involved in cosmetology and drug discovery. [Read more…]
…or how to make your protein attractive
Biomagnetic separation is a powerful lab tool in protein biochemistry which can be used in a wide range of applications including analysis tools (for protein solubility and protein-protein interaction studies, and for testing several purification buffers…), high throughput screening (HTS) and larger protein purification scale.
Indeed, it’s an easy, quick and efficient method to purify recombinant proteins and antibodies. Note that it also can be used to remove endotoxins and abundant protein contaminants from samples. Let’s take a look together at the large number of possibilities available and how we can help you to design the most adapted protocol for your study.
The role of the interactions between tumor cells and their microenvironment (TME) is now well-established in various stages of cancer development. Cytokines, produced by both the cancer and the immune cells, actively contribute to these critical connections (see the previous posts related to the crosstalk between cancer and immune cells in relation to tumor escape, immunoediting and immunosurveillance).
In a recent review published in BBA, RayBiotech‘s team highlights the “cytokine signatures and dynamics” seen during cancer development. They also demonstrate the necessity of designing relevant multiplex immunoassays for the profiling and the quantification of cytokines in biomarker and anti-cancer drug discovery programs.
Valerie Sloane Jones, Ren-Yu Huang, Li-Pai Chen, Zhe-Sheng Chen, Liwu Fu, Ruo-Pan Huang “Cytokines in cancer drug resistance: Cues to new therapeutic strategies” (2016) Biochimica et Biophysica Acta, Volume 1865, Issue 2, 255–265. DOI:10.1016/j.bbcan.2016.03.005.
Download the publication written by RayBiotech, the leader in planar Antibody Arrays.
Monoclonal antibody (mAb) engineering and their development as therapeutic or diagnostic tools have become the must in pharmaceutical industry, in medical biotech and in the research world. Purification of this type of biosimilar requires a particular know-how.
Because of their rapid growth and their affordability, bacterial expression systems are very convenient when producing recombinant proteins.
Nevertheless, one of the key elements in the design of the experimental procedures for producing a recombinant protein in E. Coli is the selection of the right bacterial strain for the right protein. This is not an easy step but remains of utmost importance.
Based on our in-house experience, we’ve compiled a guide aimed at helping you in your choice of the “ideal” engineered bacterial strain for efficient recombinant proteins expression.
You’ll find useful information for selecting the reliable strains suited to your downstream applications, with characteristics (quality, biological activity, folding…).
Interested? Download your copy here:
Guide to choosing the best bacterial strains for recombinant protein expression
Pharmaceutical, biotech and medical device industries apply restrictive quality systems in their bio-production processes. Among the numerous parameters controlled daily by scientists, I have selected a particular one for this post, i.e endotoxin detection.
Isolation of highly purified untagged proteins is crucial in today’s R&D programs. Up to now, recombinant protein production approaches were often based on the use of “tags” to make protein purification (and solubility) more convenient. Unfortunately, these tags can be real experimental hurdles in downstream applications. Protein experts are now considering “tag-free” alternatives (including outsourcing) for producing untagged proteins more rapidly, more efficiently, and without jeopardizing the rest of the research project. Let’s see how this is possible.
A recent article by E. Langer (E. Langer, “Another In-House Operation Gets Outsourced” (2015) Pharmaceutical Technology 39 (6)) describes the growing trend in companies worldwide to outsource some of their key activities. Apart from those traditionally outsourced (e.g. API biologics manufacturing, fill / finish operations, etc), analytical testing is on a growing trend, and estimations indicate that it will be the area of fastest growth for outsourcing.
At tebu-bio, we are well aware of this. Some years ago, we took the strategic decision of having our own lab. We did not want to limit assistance to our customers to technical advice or logistics solutions, but to really provide support in their key projects, enabling them to access the most innovative tools in the market.
Peroxisome Proliferator-Activated Receptors (PPARs) are ligand-activated transcription factors of the Nuclear Receptor superfamily. PPAR active compounds are of significant interest in multiple pharmaceutical domains.
In this post, we’ll highlight a clever in vitro experimental approach to screen the PPAR-specific activity of therapeutically significant PPAR agonists or antagonists.
EnSens assays, a new protease activity assay technology, which are produced by Enzium, were recently introduced to the European market. A number of assays are available from catalog, such as activity assays for MMP-2, MMP-9, MMP-14, MMP-25, ADAM10, ADAM17, Factor Xa, Furin, and Thrombin.
But what about if what you’re looking for is not available? In this post, we’ll take a look at how you can get an optimal substrate for your protease of interest, even if it is not yet obtainable from catalog.
First, let’s take a look at the EnSens assay technology itself. It’s based on a non-FRET technology and makes use of a protein substrate expressed in E. coli which is a modular dumbbell comprising two domains separated by a linker that contains a highly specific protease recognition sequence. One domain is the dye-binding domain, and the other is a blocking domain. When the linker is cleaved by a protease, separating the two domains, the binding domain is free to bind dye, constraining it and causing it to fluoresce (see Figure below).
EnSens assays overcome limitations of FRET based protease assays
- the substrate can incorporate full recognition site sequences – in FRET assays the recognition sites usually have to be shorter which can result in a number of false positives and negatives because the recognition site might not be highly selective.
- The substrate is an scFv-based protein (single-chain variable fragment, an artificially generated antibody fragment) which confers high stability in vitro and in vivo.
- The EnSens se-Red fluorophore is resistant to photobleaching up to 48 hours
- The long emission wavelength (665nm) reduces interference from other assay components
- The assay works stably in wide range of pH, salt, & solvent conditions
- Substrate and fluorophore are separate in the systems, so the fluorophore is constantly renewed in solution
- The system is characterized by high signal-to-noise ratios: 6-20x
- The read-out can be done in standard plate or cuvette fluorimeters
- The EnSens assay gives repeatable and reproducible kinetic activity curves from reagent to reagent
and finally (and this is where it gets interesting for non-catalog items!):
- The substrate is modular, allowing easy swapping of protease recognition sites – thus customized substrates can be obtained if you know the recognition site of your protease of interest
So, you can get your customized protease substrate!
In other words: If you want to screen for modulators/inhibitors of a protease with a known recognition site, you simply need to provide the sequence of the site – and the substrate and the complete EnSens assay can be designed for you in cooperation with Enzium.
Interested in a highly specific protease assay for your screening? Get in touch through the form below, I’m sure a tailored solution can be found to match your needs exactly!