Enzymes: A Very Short Introduction QUOTES
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" Although a few enzymes (e.g. carbonic anhydrase) catalyse a single isolated reaction, most are part of a team that catalyses a series of reactions in which each enzyme picks up its predecessor’s product, taking it a step further to create a metabolic pathway. This pathway may be to build up, say, an amino acid from simpler starting molecules, or conversely to break down food molecules to yield new chemical building blocks and sometimes also to trap useable energy. Life is the combined outcome of this seemingly logical enzyme teamwork. Like most things in the living world, this gives the appearance of purposeful planning down to the last detail. Such meticulous perfection would in past eras have been confidently attributed to the attentive skill of an all-powerful Creator. Since Charles Darwin, however, we have an alternative way of explaining how things in the living world come to be the way they are. Darwin led us to understand that natural selection could bring about stepwise beneficial adaptation over thousands or even millions of years, and, in the 150 years since the Origin of Species, we have learnt far more about the genetic mechanisms that can bring about such change. Does this kind of thinking work at the molecular level when we come to look at metabolic pathways and individual enzymes?
In fact the study of enzymes and other proteins allows us to be a great deal more certain than Victorian biologists could be. Many of the distinctive biological characteristics studied in comparing animals and plants, like eye colour or wing shape, have turned out to be controlled by multiple genes, whereas, in looking at individual proteins, we are looking at the products of individual genes, and latterly we can even examine those genes directly. The possibility of determining protein amino acid sequences, and, more recently, the corresponding DNA sequences, allows comparison of the same enzyme from many species and also of enzymes catalysing different but similar reactions from a single species. "
5 " Protein engineering has moved from a wary adventure on the part of a few pioneering groups in the 1980s to a routine tool used around the world today on a vast range of targets, and with immense power for fine-tuning the properties of enzymes and other proteins for practical applications. In particular, enzyme catalysis has at last gained widespread acceptance as a tool for chemistry, and, because enzyme catalysis avoids the need for high temperatures and pressures and toxic waste streams, it has become the basis of what is now generally known as ‘green chemistry’. One recent indicator of this remarkable shift in the relationship between enzymology and mainstream chemistry was the share in the 2018 Nobel Prize for Chemistry for Professor Frances Arnold at Caltech who has in recent years pioneered major advances in the methodology for efficient development of novel biocatalysts. "
