The Nobel Prizes of Chemistry of 2018 addresses three laureates, Frances H. Arnold with half of the prize share, George P. Smith with a quarter of the prize share and Sir Gregory P. Winter with another one fourth of the prize share. Frances H. Arnold was awarded for her discoveries ”for the directed evolution of enzymes”; George P. Smith and Sir Gregory P. Winter “for the phage display of peptides and antibodies”. The research done by Frances H. Arnold plays a serious role in environmental protection mainly with the study of enzymes.

Frances’ researching method is based on the evolutionary theory; Unlike how each species evolve with time and choose the most desired feature for themselves, Frances and her team utilized artificial selection to preserve the most desired function of an enzyme. she used subtilisin obtained from Bacillus subtilis to conduct directed evolution. Frances picks out the segment in Bacillus subtilis that contains subtilisin and introduced random mutation, then injected subtilisin back into Bacillus subtilis so that it can evolve depends on virus’ rapid reproduction. At the end of the day, the experimenters would pick the best enzyme that had been generated by evolution.

Substilin is known to be able to hydrolyze the casein in milk; and the final result showed that the modified enzyme (subtilisin) was able to hydrolyze the casein 256x better than the original enzyme.

Frances had also mentioned “DNA Shuffling” technique invented by Willem P. C. Stemmer in her lecture. “DNA Shuffling” is a process of recombination and creation of a gene library with all possible outcomes of enzymes. Scientists are able to choose the enzyme with the best function among the library. With “DNA Shuffling”, the enzymes are able to perform even better on their tasks of hydrolyzing casein.

As science undergoes a rapid growth, many kinds of industries are also trying to develop new products and techniques alone with the growth in science. Among them, chemical industry is making much difference to the world with numerous chemicals; While the growth is taking place in the industrial market, the pollution and harm caused by the chemicals are also evident. The “directed evolution of enzymes” by Frances H. Arnold is so important for the science community and the industrial market because it reduces the amount of co-factors, which is the source of pollution, in a chemical reaction. Just like the incredible effect the new enzyme had on the casein, the enzymes are also one of the ultimate resolutions to reduce pollution from the beginning.


https://www.nobelprize.org/prizes/chemistry/2018/arnold/lecture/ (Frances H. Arnold’s Nobel Lecture)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5901037/ (Frances H. Arnold’s Research)

https://www.che.caltech.edu/groups/fha/publications/Arnold_ACR_1998.pdf (Frances H. Arnold’s Research)

Wenqian L. Posted on Dec. 23. 2018

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