Twyman Research Management
Specialist consultants in
scientific project development,
management and presentation
to Twyman Research Management
Twyman Research Management Ltd is a UK company that specializes in scientific project development, management and presentation, including the preparation of research proposals, project management and reporting, project dissemination and complementary activities, and expert assistance with the preparation, editing and revision of scientific manuscripts.
We have been working for more than 20 years to develop and manage research projects and improve the quality of scientific publications.
Article of the Month
The primary component of most fungal cell walls is chitin, a natural polymer also found in the shells of crustaceans and insects. The human immune system recognizes chitin and can therefore repel most fungal pathogens. Some fungi produce enzymes known as chitin deacetylases that convert their cell wall chitin into a modified form known as chitosan, but incomplete conversion leads to the production of chitosan structures with multiple acetyl groups that still alert the immune system. In February's article of the month, Hembach et al. show how the aggressive fungal pathogen Cryptococcus neoformans has solved this problem by producing a deacetylase known as Cda4 that prefers chitosan as a substrate, thereby removing even more of the acetyl groups and forming a version of chitosan that is no longer perceived as a danger signal. The identification of this key enzyme provides a target for the development of new drugs to prevent cryptococcosis.
Article details: Hembach L et al. (2020) Unique subsite specificity and potential natural function of a chitosan deacetylase from the human pathogen Cryptococcus neoformans. Proc Natl Acad Sci USA 117 (7) 3551–3559.
Image shows encapsulated cells of the yeast Cryptococcus neoformans.
Image credit: CDC/Dr Leanor Haley.
Natural enzymes are usually optimized for industrial applications by introducing mutations that improve properties such as stability, substrate selection or catalytic turnover. Enzyme libraries can be combined with activity assays to screen large numbers of variants, and this is sufficient to screen all possible individual mutations at all sites. However, combinations of two or more mutations increase the number of potential variants far beyond current screening capabilities, and some kind of rational selection must be implemented to identify promising candidates. In January's article of the month, Ostafe et al. use machine learning to find the optimal combination of five independent mutations in the enzyme glucose oxidase, leading to an enzyme variant that remains active across a broad pH range and shows greater specificity for two different mediators. Machine learning can therefore be used to predict structure–activity relationships and streamline the optimization of enzymes by directed evolution.
Article details: Ostafe R et al. (2020) One‐shot optimization of multiple enzyme parameters: Tailoring glucose oxidase for pH and electron mediators. Biotechnol Bioeng 117 (1) 17–29.
Image shows a space-filling model of the enzyme glucose oxidase.
Image credit: wwPDB, created with NGL Viewer.
Plants flower in response to various environmental cues including the day length, a phenomenon known as photoperiodism. Some plants flower only when days are short, others only when days are long, and others like tobacco (Nicotiana tabacum) can flower regardless of the day length (day neutral). This is controlled by FLOWERING LOCUS T (FT) proteins, some acting as activators and some as repressors. In December's article of the month, Schmidt et al. analyze the role of the NtFT5 gene and report that it is an indispensable major floral activator during long days. They show that tobacco plants with only one functional copy of this gene remain in the vegetative growth phase for longer, producing about 10% more biomass before flowering and also producing more seeds. NtFT5 could therefore be used as a means to increase the yields of other crop species.
Article details: Schmidt FJ et al. (2020) The major floral promoter NtFT5 in tobacco (Nicotiana tabacum) is a promising target for crop improvement. Front Plant Sci 10, 1666.