A bacteriophage, also known informally as a phage, is a virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν, meaning "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm.
Sidney Altman was a Canadian-American molecular biologist, who was the Sterling Professor of Molecular, Cellular, and Developmental Biology and Chemistry at Yale University. In 1989, he shared the Nobel Prize in Chemistry with Thomas R. Cech for their work on the catalytic properties of RNA.
Frederick Sanger was a British biochemist who received the Nobel Prize in Chemistry twice.
Kurt Wüthrich is a Swiss chemist/biophysicist and Nobel Chemistry laureate, known for developing nuclear magnetic resonance (NMR) methods for studying biological macromolecules.
Salvador Edward Luria was an Italian microbiologist, later a naturalized U.S. citizen. He won the Nobel Prize in Physiology or Medicine in 1969, with Max Delbrück and Alfred Hershey, for their discoveries on the replication mechanism and the genetic structure of viruses. Salvador Luria also showed that bacterial resistance to viruses (phages) is genetically inherited.
A phagemid or phasmid is a DNA-based cloning vector, which has both bacteriophage and plasmid properties. These vectors carry, in addition to the origin of plasmid replication, an origin of replication derived from bacteriophage. Unlike commonly used plasmids, phagemid vectors differ by having the ability to be packaged into the capsid of a bacteriophage, due to their having a genetic sequence that signals for packaging. Phagemids are used in a variety of biotechnology applications; for example, they can be used in a molecular biology technique called "phage display".
Alfred Day Hershey was an American Nobel Prize–winning bacteriologist and geneticist.
Phage display is a laboratory technique for the study of protein–protein, protein–peptide, and protein–DNA interactions that uses bacteriophages to connect proteins with the genetic information that encodes them. In this technique, a gene encoding a protein of interest is inserted into a phage coat protein gene, causing the phage to "display" the protein on its outside while containing the gene for the protein on its inside, resulting in a connection between genotype and phenotype. The proteins that the phages are displaying can then be screened against other proteins, peptides or DNA sequences, in order to detect interaction between the displayed protein and those of other molecules. In this way, large libraries of proteins can be screened and amplified in a process called in vitro selection, which is analogous to natural selection.
Filamentous bacteriophages are a family of viruses (Inoviridae) that infect bacteria, or bacteriophages. They are named for their filamentous shape, a worm-like chain, about 6 nm in diameter and about 1000-2000 nm long. This distinctive shape reflects their method of replication: the coat of the virion comprises five types of viral protein, which are located in the inner membrane of the host bacterium during phage assembly, and these proteins are added to the nascent virion's DNA as it is extruded through the membrane. The simplicity of filamentous phages makes them an appealing model organism for research in molecular biology, and they have also shown promise as tools in nanotechnology and immunology.
M13 is one of the Ff phages, a member of the family filamentous bacteriophage (inovirus). Ff phages are composed of circular single-stranded DNA (ssDNA), which in the case of the m13 phage is 6407 nucleotides long and is encapsulated in approximately 2700 copies of the major coat protein p8, and capped with about 5 copies each of four different minor coat proteins. The minor coat protein p3 attaches to the receptor at the tip of the F pilus of the host Escherichia coli. The life cycle is relatively short, with the early phage progeny exiting the cell ten minutes after infection. Ff phages are chronic phage, releasing their progeny without killing the host cells. The infection causes turbid plaques in E. coli lawns, of intermediate opacity in comparison to regular lysis plaques. However, a decrease in the rate of cell growth is seen in the infected cells. The replicative form of M13 is circular double-stranded DNA similar to plasmids that are used for many recombinant DNA processes, and the virus has also been used for phage display, directed evolution, nanostructures and nanotechnology applications.
Sir Gregory Paul Winter is a Nobel Prize-winning English molecular biologist best known for his work on the therapeutic use of monoclonal antibodies. His research career has been based almost entirely at the MRC Laboratory of Molecular Biology and the MRC Centre for Protein Engineering, in Cambridge, England.
Directed evolution (DE) is a method used in protein engineering that mimics the process of natural selection to steer proteins or nucleic acids toward a user-defined goal. It consists of subjecting a gene to iterative rounds of mutagenesis, selection and amplification. It can be performed in vivo, or in vitro. Directed evolution is used both for protein engineering as an alternative to rationally designing modified proteins, as well as for experimental evolution studies of fundamental evolutionary principles in a controlled, laboratory environment.
Biopanning is an affinity selection technique which selects for peptides that bind to a given target. All peptide sequences obtained from biopanning using combinatorial peptide libraries have been stored in a special freely available database named BDB. This technique is often used for the selection of antibodies too.
Frances Hamilton Arnold is an American chemical engineer and Nobel Laureate. She is the Linus Pauling Professor of Chemical Engineering, Bioengineering and Biochemistry at the California Institute of Technology (Caltech). In 2018, she was awarded the Nobel Prize in Chemistry for pioneering the use of directed evolution to engineer enzymes.
Morten Peter Meldal is a Danish chemist and Nobel laureate. He is a professor of chemistry at the University of Copenhagen in Copenhagen, Denmark. He is best known for developing the CuAAC-click reaction, concurrently with but independent of Valery V. Fokin and K. Barry Sharpless.
Cambridge Antibody Technology Group Plc, was a biotechnology company headquartered in Cambridge, England, United Kingdom. Its core focus was on antibody therapeutics, primarily using Phage Display and Ribosome Display technology.
John McCafferty is a British scientist, one of the founders of Cambridge Antibody Technology alongside Sir Gregory Winter and David Chiswell. He is well known as one of the inventors of scFv antibody fragment phage display, a technology that revolutionised the monoclonal antibody drug discovery. McCafferty and his team developed this process following failures previously generating antibodies by immunizing mice. Later improvements of antibody phage display technology enables the display of millions of different antibody fragments on the surface of filamentous phage and subsequent selection of highly specific recombinant antibodies to any given target. This technology is widely exploited in pharmaceutical industry for the discovery and development of therapeutic monoclonal antibodies to treat mainly cancer, inflammatory and infectious diseases. One of the most successful was HUMIRA (adalimumab), discovered by Cambridge Antibody Technology as D2E7 and developed and marketed by Abbott Laboratories. HUMIRA, an antibody to TNF alpha, was the world's first phage display derived fully human antibody, which achieved annual sales exceeding $1bn therefore achieving blockbuster status. Humira went on to dominate the best-selling drugs lists - in 2016: The best selling drugs list researched by Genetic Engineering & Biotechnology News, published in March 2017, details that Humira occupied the number 1 position for 2015 and 2016. Whilst for 2017, Abbvie reports that Humira achieved $18.427billion of sales in 2017
Willem P. C. "Pim" Stemmer was a Dutch scientist and entrepreneur who invented numerous biotechnologies. He was the founder and CEO of Amunix Inc., a company that creates "pharmaceutical proteins with extended dosing frequency". His other prominent inventions include DNA shuffling, now referred to as molecular breeding. He holds more than 97 patents. Stemmer was honored with the Charles Stark Draper Prize in 2011 for the pioneering contributions to directed evolution which won the Nobel Prize in Chemistry in 2018. He was elected as member of National Academy of Engineering.
Ff phages is a group of almost identical filamentous phage including phages f1, fd, M13 and ZJ/2, which infect bacteria bearing the F fertility factor. The virion is a flexible filament measuring about 6 by 900 nm, comprising a cylindrical protein tube protecting a single-stranded circular DNA molecule at its core. The phage codes for only 11 gene products, and is one of the simplest viruses known. It has been widely used to study fundamental aspects of molecular biology. George Smith and Greg Winter used f1 and fd for their work on phage display for which they were awarded a share of the 2018 Nobel Prize in Chemistry. Early experiments on Ff phages used M13 to identify gene functions, and M13 was also developed as a cloning vehicle, so the name M13 is sometimes used as an informal synonym for the whole group of Ff phages.
Ada E. Yonath is an Israeli crystallographer and Nobel laureate in Chemistry, best known for her pioneering work on the structure of ribosomes. She is the current director of the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly of the Weizmann Institute of Science.
