Enzyme Forced Evolution

The complexity of all living things is due to mutation and natural selection, or so Darwinists believe. The exquisite products of evolution are apparent at all levels, from the amazing diversity of life all the way down to individual protein molecules. It is these molecules in which scientists and engineers wish to redesign by implementing the idea of ‘forced evolution’. This directed evolution allows us to explore enzyme functions never required in the natural environment. We are able to obtain the ability to tailor individual proteins in order to optimise their functioning in biotechnology. For example, when natural enzymes are recruited for industrial applications, from serving as catalysts in chemicals synthesis to additives for laundry detergents, we discover that they are often not well suited to these tasks. Due to poor substrate solubility, breakdown of unstable products, or competing chemical reactions, the conditions for an enzyme reaction may be unsuitable for large-scale applications. Evolution is the culprit: enzymes are optimised and often highly specialised for specific biological functions within the context of a living organism. Biotechnology, in contrast, nee

Subsequently, the Random Priming Process was invented. It is similar to the Stemmer process, except that gene fragments are produced by using short PCR cycles and random primers. These fragments are then assembled into full genes in a fashion similar to the Stemmer process. The main advantage of this approach is that it requires much smaller amounts of starting DNA.

The majority of the gene shuffling method is carried out in vitro, however some in vivo techniques have been developed and can also yield interesting new chimeric enzymes but the diversity may be more limited than that obtained by in vitro methods.

There are various examples of how gene shuffling is used to obtain ‘better’ enzymes. One good illustration is that of Stemmers attempt to improve the green fluorescent protein (GFP) commonly used as a detection system. After only three rounds of shuffling, a variant was identified which gave a 42-fold improvement over the parental sequence. What is striking about this improvement was that GFP seemed near perfect at the outset. It can compromise 75% of total protein mass with no toxicity, and has a quantum yield as a fluorophore between .7 and .8. Careful observation uncovered the improvement. It was found that the improved protein was more soluble under intracellular conditions, while the wild-type tended to form inclusion bodies at relatively low concentrations. It is unlikely that such a solution would have been generated by rational design. Directed evolution required no knowledge of the limiting factor.

Some topics in this essay:
Evolution-Gene Shuffling, Priming Process, WPC Stemmer, gene shuffling, directed evolution, pcr cycles, creating genetic diversity, site directed mutagenesis, short pcr cycles, similar stemmer process, stemmer process, beneficial mutations, site directed, genetic diversity, short pcr, directed mutagenesis, creating genetic,