Desensitizing
Feedback
Inhibition -
Very often, particularly in the biosynthesis of amino acids, the surplus end product acts on one of the first few enzymes of biosynthetic pathway rendering it inactive. In industry, we may like to get the end product in maximum quantity disregarding the need of the cell.
This can be achieved if the feedback inhibition by the end product is desensitized. Mutant enzymes have actually been isolated, which do not respond to feedback inhibition. However, this objective can also be achieved by using cloned genes.
One of the popular examples involving desensitizing feedback inhibition for metabolic engineering includes improved threonine production by Brevibacterium lactofermentum. A mutant M-15 was isolated, which lacked feedback inhibition of aspartokinase by threonine and lysine and of homoserine dehydrogenase (HD) by threonine.
