Enzymes are the catalysts for biochemical reactions. As such, they speed up the transition from reactants to products without being consumed in the process. Multiple enzymes can be found in every cell, from bacteria up through to humans. We as humans have found ways to exploit enzymes to produce food products, fuel, pharmaceutical products, biotechnological tools, sensors, and much more. The potential uses for enzymes are seemingly limitless. The creation of solid support structures with immobilized enzymes has improved our ability to reuse enzymes in a controlled manner for a variety of applications. Immobilized enzymes can be reused multiple times before their efficacy is lost. This allows them to be an affordable part of industrial processes.
Lluis M. Martínez, SEPMAG Chief Scientific Officer
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Until this point we have been thinking about antibodies as one of the five classes, IgG, IgE, IgD, IgA, or IgM. The basic unit of each antibody class is a Y structure, where the base of the Y is known as the Fc region and the arms are the Fab region. The entire IgG antibody is composed of four polypeptide chains (two heavy and two light). The Fc region is composed only of heavy chain, and the variable Fab region is built with heavy chain and light chain. The Fab region is where all of the antigen-binding occurs because the paratope, or antigen recognition site is located at the tip of each of the two arms of the Y. A single domain antibody paratope is made solely of a single heavy chain.
The structure of the most commonly known antibody class (IgG) was a mystery until 1959, when it was elucidated by Edelman and Porter . The duo approached the question from two very different directions, but they were both awarded the 1972 Nobel Prize in Physiology or Medicine for their groundbreaking work. Gerald Edelman said that he was, “fascinated by the specificity of antigen recognition by antibodies,” and hoped that, “by doing the primary structure of antibody molecules, the basis of their specificity would be revealed.” Indeed, it was.
Pharmaceutical validation is important to the manufacturing process to ensure product consistency and safety. It involves regulation of all raw materials and production procedures as well as testing of final product. The general rule of thumb is to follow good manufacturing practice (GMP). This demands that all protocols be up to date and followed by trained personnel. It also requires that equipment be well-maintained and inspected. In the case of clean-room usage the clean room needs to be verified.
We have come a long way from the days of blood letting, trephination, and snake oil salesmen peddling cure-all tonics. The oversight and regulation of organizations such as the European Medicines Agency and the Federal Drug Administration (FDA) have significantly improved the quality and safety of our medical and pharmaceutical products. Of course, our medical understanding has deepened dramatically, our science has become more sophisticated, and we have developed tools to perform large scale drug discovery and screening. With this deeper understanding of chemistry and drug development we have realized the importance of preserving the chemical molecules via proper storage conditions.
The ICH guidelines for stability lay out the requirements for identifying and maintaining drug efficacy by understanding the pathways of degradation. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) was founded in 1990. The European Commission, FDA from the USA, and the Ministry of Health, Labour, and Welfare (MHLW), which later became the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan are all founding members. Since that time, many other regulatory authorities from around the world have joined the ICH. The stated mission of the ICH is to “achieve greater harmonisation worldwide to ensure that safe, effective, and high quality medicines are developed and registered in the most resource-efficient manner.”
Superparamagnetism is a type of magnetism that lies between that of a permanent magnet and a paramagnet. Recall that a permanent magnet is always magnetic at temperatures below its Curie Temperature even in zero applied magnetic field, whereas a paramagnet is not magnetic at zero applied field but can become magnetic when an external magnetic field is applied. The potential for a paramagnet to be induced to have magnetization is called magnetic susceptibility. A superparamagnet behaves similarly to a paramagnet. The “super” means that it has a higher magnetic susceptibility than a regular paramagnet when a magnetic field is applied. Superparamagnets are typically made of iron oxide or other ferrous materials, and they are extremely small, on the order of 10-100 nanometers.
Proteins are constantly being created by the cellular machinery of living organisms. This article will first summarize the process as it occurs in a natural organism, and then discuss how protein expression and purification occurs in a laboratory setting for the generation of recombinant proteins.
In bacteria there are two main types of DNA—genomic and plasmid. Plasmid DNA is unique to bacteria. Eukaryotic cells don't typically have plasmid DNA unless it was put there by transfection for experimental purposes. The most important goal when isolating nucleic acids is to obtain the highest purity genetic material possible. When isolating genomic DNA it is important to remove plasmid DNA and RNA from the sample. Similarly, sometimes an experiment calls for the isolation of plasmid DNA, and the selective removal of genomic DNA is necessary. Also, some commercial RNA isolation kits include gDNA eliminator spin columns to remove genomic DNA from the isolate.
The concept of an antigen and antibody pair is central to modern medicine and biotechnology. These proteins match like a lock and key, with equisite specificity. The interactions are non-covalent, but have equilibrium constants ranging from 105 to 1012 M-1 Antibodies and antigens are proteins: polypeptide chains of amino acids. The IgG antibody is composed of four polypeptide chains, two heavy and two light, organized into a ‘Y’ shape. The base of the Y is called the Fc region, while the two tips are known as the Fab region.
Traditional immunoassays such as the enzyme-linked immunosorbent assay (ELISA) are able to measure the presence or absence of only one analyte per reaction. Multiplex immunoassays measure dozens of different analytes in a single reaction. This is particularly beneficial for precious samples, and when only a small volume is collected for analysis. The multiplex immunoassay also saves working time since multiple assays can be completed simultaneously.
