Promiscuity condition

For 3.8 billion years, enzyme evolution has occurred primarily in microbes exposed to novel environmental conditions. However, in the last two decades, new methods have been developed for laboratory evolution of enzymes for production of chemicals, pharmaceuticals, and biofuels. Directed evolution has been widely used to improve thermostability and alter substrate specificity. Current efforts aim to improve the catalytic abilities of evolved enzymes, which are usually considerably poorer than those of naturally occurring enzymes, and to evolve novel pathways using promiscuous activities of existing enzymes. These efforts will provide new insights into the adaptation of protein scaffolds for new functions that will both help us to understand the evolutionary history of modern enzymes and provide the basis for a wide range of applications in biotechnology. 

Under conditions of in vitro testing, compounds which inhibit the growth and survival of a variety of cell types can legitimately be called "antiplasmodial" however, the meaning of the term is obscured due to the promiscuous nature of the toxicity. The inclusion of a selectivity parameter along with "antimalarial" data rejxrrted in the literature, is suggested here to facilitate a more qualitative evaluation of compounds with genuine potential as antimalarial lead compounds. 

---