Juan Asenjo

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Juan A. Asenjo de Leuze de Lancizolle

Professor Juan A. Asenjo (born October 7, 1949) [1] is a Chilean chemical engineer who specialises in biotechnology. He currently serves as the director of the Centre for Biochemical Engineering and Biotechnology at the University of Chile and is the President of the Chilean Academy of Science. [2]

Contents

Education and career

Asenjo studied for his first degree in chemical engineering at the University of Chile, graduating in 1974. He then moved to the University of Leeds, UK to complete an MSc, followed by a PhD at University College London supervised by Peter Dunnill and M. D. Lilly. He moved back to Chile for one year before being appointed Assistant Professor in biochemical engineering at Columbia University, New York where he remained until 1986. In 1987 he moved to the University of Reading to become a Reader in biochemical engineering and the director of the biochemical engineering laboratory. Then in 1995 he returned to Chile and established the Centre for Biochemical Engineering and Biotechnology at the University of Chile which he continues to direct. [3]

Research

Asenjo has made scientific contributions where the fields of mathematics and computer science merge with biology and biotechnology. This has included developing models of enzyme systems for the lysis of microbial cells [4] and for predicting the behaviour of proteins in aqueous two-phase systems. [5] He has been involved in the purification of several proteins including alpha amylase, [6] tissue plasminogen activator, monoclonal antibodies [7] and virus-like particles. [8] Recently his group have begun working in the fields of protein engineering, metabolic engineering and functional genomics. [2] One specific area of research is an attempt to produce detergents which work at low temperatures based on trypsin enzymes originally isolated from Antarctic krill. [9] [10] The Santiago Times reported in 2013 that Asenjo's group was to begin testing a vaccine for alcoholism on mice and hoped to begin pre-clinical trials in humans later that year. [11] In November 2013 the vaccine was in stage 2 clinical trials. The vaccine acts to inhibit acetaldehyde dehydrogenase causing people to experience a hangover shortly after consuming alcohol. [12]

He has called for Chile to invest more in scientific research and development, which would allow the country to add value to its exports, for example by exporting lithium batteries rather than raw lithium. [13] [14]

Recognition

He was elected as a member of the Chilean Academy of Science in 1999 and was appointed as its Vice President in 2004 and President in 2010. [3] In 2004 he was awarded the Chilean National Prize for Applied Sciences and Technologies, with the jury noting his research was of a high impact and quality, as demonstrated by over 100 publications, several patents and having supervised over 40 doctoral students. [9]

In 2018, Asenjo was elected a member of the National Academy of Engineering for contributions to protein separations for the biotechnology industry and to biotechnology research, development, and entrepreneurship in Chile.

Related Research Articles

<span class="mw-page-title-main">Protein</span> Biomolecule consisting of chains of amino acid residues

Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity.

Lysis is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a lysate. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles.

A lysis buffer is a buffer solution used for the purpose of breaking open cells for use in molecular biology experiments that analyze the labile macromolecules of the cells. Most lysis buffers contain buffering salts and ionic salts to regulate the pH and osmolarity of the lysate. Sometimes detergents are added to break up membrane structures. For lysis buffers targeted at protein extraction, protease inhibitors are often included, and in difficult cases may be almost required. Lysis buffers can be used on both animal and plant tissue cells.

<span class="mw-page-title-main">Exoenzyme</span> Enzyme that functions outside the cell it is secreted from

An exoenzyme, or extracellular enzyme, is an enzyme that is secreted by a cell and functions outside that cell. Exoenzymes are produced by both prokaryotic and eukaryotic cells and have been shown to be a crucial component of many biological processes. Most often these enzymes are involved in the breakdown of larger macromolecules. The breakdown of these larger macromolecules is critical for allowing their constituents to pass through the cell membrane and enter into the cell. For humans and other complex organisms, this process is best characterized by the digestive system which breaks down solid food via exoenzymes. The small molecules, generated by the exoenzyme activity, enter into cells and are utilized for various cellular functions. Bacteria and fungi also produce exoenzymes to digest nutrients in their environment, and these organisms can be used to conduct laboratory assays to identify the presence and function of such exoenzymes. Some pathogenic species also use exoenzymes as virulence factors to assist in the spread of these disease-causing microorganisms. In addition to the integral roles in biological systems, different classes of microbial exoenzymes have been used by humans since pre-historic times for such diverse purposes as food production, biofuels, textile production and in the paper industry. Another important role that microbial exoenzymes serve is in the natural ecology and bioremediation of terrestrial and marine environments.

<span class="mw-page-title-main">Bioreactor</span> System that supports a biologically active environment

A bioreactor is any manufactured device or system that supports a biologically active environment. In one case, a bioreactor is a vessel in which a chemical process is carried out which involves organisms or biochemically active substances derived from such organisms. This process can either be aerobic or anaerobic. These bioreactors are commonly cylindrical, ranging in size from litres to cubic metres, and are often made of stainless steel. It may also refer to a device or system designed to grow cells or tissues in the context of cell culture. These devices are being developed for use in tissue engineering or biochemical/bioprocess engineering.

The first isolation of deoxyribonucleic acid (DNA) was done in 1869 by Friedrich Miescher. DNA extraction is the process of isolating DNA from the cells of an organism isolated from a sample, typically a biological sample such as blood, saliva, or tissue. It involves breaking open the cells, removing proteins and other contaminants, and purifying the DNA so that it is free of other cellular components. The purified DNA can then be used for downstream applications such as PCR, sequencing, or cloning. Currently, it is a routine procedure in molecular biology or forensic analyses.

Affinity chromatography is a method of separating a biomolecule from a mixture, based on a highly specific macromolecular binding interaction between the biomolecule and another substance. The specific type of binding interaction depends on the biomolecule of interest; antigen and antibody, enzyme and substrate, receptor and ligand, or protein and nucleic acid binding interactions are frequently exploited for isolation of various biomolecules. Affinity chromatography is useful for its high selectivity and resolution of separation, compared to other chromatographic methods.

Pharming, a portmanteau of farming and pharmaceutical, refers to the use of genetic engineering to insert genes that code for useful pharmaceuticals into host animals or plants that would otherwise not express those genes, thus creating a genetically modified organism (GMO). Pharming is also known as molecular farming, molecular pharming, or biopharming.

<span class="mw-page-title-main">Liquid–liquid extraction</span> Method to separate compounds or metal complexes

Liquid–liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds or metal complexes, based on their relative solubilities in two different immiscible liquids, usually water (polar) and an organic solvent (non-polar). There is a net transfer of one or more species from one liquid into another liquid phase, generally from aqueous to organic. The transfer is driven by chemical potential, i.e. once the transfer is complete, the overall system of chemical components that make up the solutes and the solvents are in a more stable configuration. The solvent that is enriched in solute(s) is called extract. The feed solution that is depleted in solute(s) is called the raffinate. Liquid–liquid extraction is a basic technique in chemical laboratories, where it is performed using a variety of apparatus, from separatory funnels to countercurrent distribution equipment called as mixer settlers. This type of process is commonly performed after a chemical reaction as part of the work-up, often including an acidic work-up.

Industrial fermentation is the intentional use of fermentation in manufacturing processes. In addition to the mass production of fermented foods and drinks, industrial fermentation has widespread applications in chemical industry. Commodity chemicals, such as acetic acid, citric acid, and ethanol are made by fermentation. Moreover, nearly all commercially produced industrial enzymes, such as lipase, invertase and rennet, are made by fermentation with genetically modified microbes. In some cases, production of biomass itself is the objective, as is the case for single-cell proteins, baker's yeast, and starter cultures for lactic acid bacteria used in cheesemaking.

Aqueous biphasic systems (ABS) or aqueous two-phase systems (ATPS) are clean alternatives for traditional organic-water solvent extraction systems.

<span class="mw-page-title-main">Glycogen branching enzyme</span> Mammalian protein involved in glycogen production

1,4-alpha-glucan-branching enzyme, also known as brancher enzyme or glycogen-branching enzyme is an enzyme that in humans is encoded by the GBE1 gene.

<span class="mw-page-title-main">Plasmid preparation</span> Biological method of DNA extraction and purification

A plasmid preparation is a method of DNA extraction and purification for plasmid DNA. It is an important step in many molecular biology experiments and is essential for the successful use of plasmids in research and biotechnology. Many methods have been developed to purify plasmid DNA from bacteria. During the purification procedure, the plasmid DNA is often separated from contaminating proteins and genomic DNA.

Daniel I-Chyau Wang was a Chinese-American chemical engineer. He was an Institute Professor at the Massachusetts Institute of Technology. He was known for founding the MIT Biotechnology Process Engineering Center and the expansion of the field of biochemical engineering.

Nitrile hydratases are mononuclear iron or non-corrinoid cobalt enzymes that catalyse the hydration of diverse nitriles to their corresponding amides:

<span class="mw-page-title-main">PEGylation</span> Chemical reaction

PEGylation is the process of both covalent and non-covalent attachment or amalgamation of polyethylene glycol polymer chains to molecules and macrostructures, such as a drug, therapeutic protein or vesicle, which is then described as PEGylated. PEGylation affects the resulting derivatives or aggregates interactions, which typically slows down their coalescence and degradation as well as elimination in vivo.

<span class="mw-page-title-main">Genetically modified bacteria</span> First organisms to be modified in the laboratory

Genetically modified bacteria were the first organisms to be modified in the laboratory, due to their simple genetics. These organisms are now used for several purposes, and are particularly important in producing large amounts of pure human proteins for use in medicine.

<span class="mw-page-title-main">Affitin</span>

Affitins are artificial proteins with the ability to selectively bind antigens. They are structurally derived from the DNA binding protein Sac7d, found in Sulfolobus acidocaldarius, a microorganism belonging to the archaeal domain. By randomizing the amino acids on the binding surface of Sac7d and subjecting the resulting protein library to rounds of ribosome display, the affinity can be directed towards various targets, such as peptides, proteins, viruses, and bacteria.

Industrial enzymes are enzymes that are commercially used in a variety of industries such as pharmaceuticals, chemical production, biofuels, food and beverage, and consumer products. Due to advancements in recent years, biocatalysis through isolated enzymes is considered more economical than use of whole cells. Enzymes may be used as a unit operation within a process to generate a desired product, or may be the product of interest. Industrial biological catalysis through enzymes has experienced rapid growth in recent years due to their ability to operate at mild conditions, and exceptional chiral and positional specificity, things that traditional chemical processes lack. Isolated enzymes are typically used in hydrolytic and isomerization reactions. Whole cells are typically used when a reaction requires a co-factor. Although co-factors may be generated in vitro, it is typically more cost-effective to use metabolically active cells.

Dye-ligand affinity chromatography is one of the Affinity chromatography techniques used for protein purification of a complex mixture. Like general chromatography, but using dyes to apply on a support matrix of a column as the stationary phase that will allow a range of proteins with similar active sites to bind to, refers to as pseudo-affinity. Synthetic dyes are used to mimic substrates or cofactors binding to the active sites of proteins which can be further enhanced to target more specific proteins. Follow with washing, the process of removing other non-target molecules, then eluting out target proteins out by changing pH or manipulate the salt concentration. The column can be reused many times due to the stability of immobilized dyes. It can carry out in a conventional way by using as a packed column, or in high-performance liquid chromatography (HPLC) column.

References

  1. "Juan Asenjo CV" (PDF). Centre for Biochemical Engineering and Biotechnology. 2011. Retrieved 2014-02-08.
  2. 1 2 "Juan Asenjo". Interamerican Network of Academies of Sciences. Retrieved 2014-02-08.
  3. 1 2 "Juan A. Asenjo, Ph.D." Centre for Biochemical Engineering and Biotechnology. Retrieved 2014-02-08.
  4. Hunter, J. B.; Asenjo, J. A. (1988). "A structured mechanistic model of the kinetics of enzymatic lysis and disruption of yeast cells". Biotechnology and Bioengineering. 31 (9): 929–43. doi:10.1002/bit.260310906. PMID   18584701.
  5. Merchuk, J. C.; Andrews, B. A.; Asenjo, J. A. (1998). "Aqueous two-phase systems for protein separation". Journal of Chromatography B. 711: 285. doi:10.1016/S0378-4347(97)00594-X.
  6. Schmidt, A. S.; Ventom, A. M.; Asenjo, J. A. (1994). "Partitioning and purification of α-amylase in aqueous two-phase systems". Enzyme and Microbial Technology. 16 (2): 131. doi:10.1016/0141-0229(94)90076-0.
  7. Andrews, B. A.; Nielsen, S; Asenjo, J. A. (1996). "Partitioning and purification of monoclonal antibodies in aqueous two-phase systems". Bioseparation. 6 (5): 303–13. PMID   9210350.
  8. Asenjo, J. A.; Ventom, A. M.; Huang, R. -B.; Andrews, B. A. (1993). "Selective Release of Recombinant Protein Particles (VLPs) from Yeast Using a Pure Lytic Glucanase Enzyme". Bio/Technology. 11 (2): 214. doi:10.1038/nbt0293-214.
  9. 1 2 "Juan Asenjo se llevó el Premio Nacional de Ciencias Aplicadas 2004". Cooperativa.cl. 2004-09-02. Retrieved 2014-02-08.
  10. "Cryophilic proteases: wash better and whiter". Centre for Biochemical Engineering and Biotechnology. Retrieved 2014-02-08.
  11. "World's first alcoholism vaccine to run preclinical trial in Chile". Santiago Times. 2013-01-22. Archived from the original on 2014-02-22. Retrieved 2014-02-08.
  12. John Lavitt (2013-11-04). "Alcohol Vaccine: A True Advance in the Treatment of Alcoholism?". Recovery View. Retrieved 2014-02-08.
  13. "Chilean senator calls for prudence in lithium development". Santiago Times. 2012-09-26. Archived from the original on 2014-02-22. Retrieved 2014-02-08.
  14. "Congreso del Futuro llamará a invertir en investigación científica". Cooperativa.cl. Retrieved 2014-02-08.