Sources of Essential Oils
K. Hüsnü Can Başer, Gerhard Buchbauer in Handbook of Essential Oils, 2020
Protein engineering is the application of scientific methods (mathematical and laboratory methods) to develop useful or valuable proteins. There are two general strategies for protein engineering, random mutagenesis and rational design. In rational design, detailed knowledge of the structure and function of the protein is necessary to make desired changes by site-directed mutagenesis, a technique already well developed. An impressive example of the rational design of monoterpene synthases was given by Kampranis et al. (2007) who converted a 1,8-cineole synthase from S. fruticosa into a synthase producing sabinene, the precursor of α- and β-thujones with a minimum number of substitutions. They went also a step further and converted this monoterpene synthase into a sesquiterpene synthase by substituting a single amino acid that enlarged the cavity of the active site enough to accommodate the larger precursor of the sesquiterpenes, farnesyl pyrophosphate.
Contact Urticaria, Dermatitis, and Respiratory Allergy Caused by Enzymes
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
Notwithstanding some rare exceptions (e.g., trypsin, chymotrypsin, rennin, papain), enzymes are named by adding the suffix “-ase” to their substrate (i.e., cellulase) or to their function (i.e., peroxidase). The catalytic activity of enzymes greatly reduces the amount of energy and the time needed to carry on a specific biochemical reaction. A little more than 20 enzymes are industrially produced. They are extracted from animal tissues, plants, and microorganisms such as bacteria, fungi, or yeasts. Their industrial applications have flourished because of the ease and low cost of growing their producing microorganisms. Nowadays, protein engineering can modify or create enzymes with increased stability or with activity on new substrates.
Chimeric VLPs
Paul Pumpens in Single-Stranded RNA Phages, 2020
The designed genetic reconstruction of proteins started in the early 1980s when Alan R. Fersht and his colleagues conceived the basic idea of the protein engineering, or mutational intervention, in the structure of proteins, which was based on spatial knowledge. Early protein engineering was oriented toward the creation of some kind of artificially improved proteins with desired functions (Winter et al. 1982; Wilkinson et al. 1983, 1984; Leatherbarrow and Fersht 1986). Since then, protein engineering as a specific branch of gene engineering has achieved much success, constructing new forms of enzymes and their inhibitors and elucidating the basic rules of protein folding and changing their specific activities (Fersht and Winter 1992).
Advances in biocatalytic and chemoenzymatic synthesis of nucleoside analogues
Published in Expert Opinion on Drug Discovery, 2022
Sebastian C. Cosgrove, Gavin J. Miller
From a technology and engineering perspective, recent reports of continuous biocatalytic nucleoside syntheses provide an intriguing snapshot of the future. The use of a process engineering approach is agnostic to the enzymatic system that is used, avoiding the requirement for protein engineering to improve enzyme performance. It also affords greater equilibrium control via substrate/product removal through continuous flow of the reaction mixture. This could remove the need for additional bespoke accessory enzymes to be researched (e.g. co-factor recycling systems) and provide a system to help with equilibrium displacement. While not all researchers have access to continuous reactor systems, such access does remove a prerequisite for advanced molecular biology skills to clone and design enzymes, an appropriate example of field of expertise synergy. Scientific disciplines will need to work in tandem (chemical vs biocatalytic approaches) and in some cases develop new relationships (e.g. to tackle scalability capabilities). When taken altogether, the discipline of enzymatic nucleoside analogue synthesis is primed for triumph. This historically privileged medicinal chemistry and drug discovery space ensures that the continued evolution of methods to improve their synthesis and structural diversity will endure.
Recent advances in automated protein design and its future challenges
Published in Expert Opinion on Drug Discovery, 2018
Dani Setiawan, Jeffrey Brender, Yang Zhang
The term protein design is, on many occasion, used interchangeably with the term protein engineering. Most protein engineering is achieved either through rational design, the evaluation of a few human selected mutations guided by comprehensive structural and biochemical knowledge, or by directed evolution by display technologies which evaluate very large mutant libraries generated by random mutagenesis at specific positions within the protein chains [11]. The success of this strategy is long and varied; nearly all protein therapeutics have been developed using some combination of the two strategies. The methods work in most cases because protein–protein interactions and enzymatic active sites are often relatively localized; evaluating one mutation site often only requires consideration of a few other sites in the immediate vicinity of the mutation – a mutation on one side of the protein surface usually does not impact the effect of a mutation on the other side. As long as the effect of the mutations is relatively localized, directed evolution by random mutagenesis can be an efficient way for searching for optimal protein sequences as a large area can be covered by independent screens.
Preclinical developments of enzyme-loaded red blood cells
Published in Expert Opinion on Drug Delivery, 2021
Luigia Rossi, Francesca Pierigè, Alessandro Bregalda, Mauro Magnani
Enzyme delivery is a medical need for several conditions, including the treatment of metabolic diseases, the treatment of acute or chronic assumption of alcohol and the treatment of certain forms of cancer. The key requirements for an effective benefit in the usage of therapeutic enzymes are listed below and, among the other, we find that the drug must be specific for the bioconversion of the target substrate, must be stable, must be retained in circulation, and has no or limited immunogenicity. These conditions are not easily obtainable and frequently one achievement is obtained at the expense of another relevant property. The selection of the therapeutic enzyme usually benefits from the genetic variability found in a number of living organisms and the selected enzyme may be advantageously optimized by protein engineering. This approach was successful in several cases. We currently have therapeutic enzymes that derive from genes present in algae, bacteria and in other living organisms but not in the human genome. A far more complex issue is the handling of immunogenicity. In fact, many therapeutic enzymes have been approved by the FDA and other regulatory agencies by the inclusion of a black box highlighting the risk of anaphylaxis and guidelines that have to be strictly followed through drug titration, administration in the presence of an expert clinician and other mandatory procedures. To overcome this critical issue experienced by several therapeutic enzymes, the protein is commonly PEGylated. PEGylation apparently reduce immunogenicity and protect the therapeutic protein from the inactivation by anti-drug antibodies but, in some cases, patients have also developed anti-PEG antibodies.
Related Knowledge Centers
- Peptide
- Protein
- Protein Design
- Protein Folding
- Amino Acid
- Directed Evolution
- Protein Structure
- High-Throughput Screening
- Expanded Genetic Code
- Site-Directed Mutagenesis