摘要 |
<p>A process for the production of an altered microbial enzyme, especially an aminotransferase, which displays catalytic activity towards the L-enantiomer of an amino acid which is not the normal substrate for the precursor enzyme comprises treating a microorganism with a mutagenic agent, growing the microorganism so treated on a medium containing said amino acid as the sole nitrogen source and isolating surviving microorganisms containing enzymes capable of using said amino acid as a substrate. The process involves the use of a random chemical mutagen followed by a biological selection procedure and does not require prior knowledge of the protein structure of the enzyme nor site-directed mutagenesis.</p> |