Related Experiment Video
Updated: Aug 12, 2025

Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
Published on: February 16, 2018
Ancestral L-amino acid oxidases for deracemization and stereoinversion of amino acids
Shogo Nakano1, Kohei Kozuka2, Yuki Minamino2
1Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan. snakano@u-shizuoka-ken.ac.jp.
Abstract:
L-amino acid oxidases (LAAOs) can be applied to convert racemic amino acids to D-isomers, which are potential precursors of pharmaceuticals. However, this application is hampered by the lack of available stable and structure-determined LAAOs. In this study, we attempt to address this limitation by utilizing two ancestral LAAOs: AncLAAO-N4 and AncLAAO-N5. AncLAAO-N4 has the highest thermal and temporal stabilities among the designed LAAOs that can be used for deracemization and stereoinversion. AncLAAO-N5 can provide X-ray crystal structures, which are helpful to reveal substrate recognition and reaction mechanisms of LAAOs at the molecular level. Next, we attempted to improve activity of AncLAAO-N4 toward L-Val through a semi-rational protein engineering method. Three variants with enhanced activity toward L-Val were obtained. Taken together, we believe that the activity and substrate selectivity of AncLAAOs give them the potential to be key enzymes in various chemoenzymatic reactions.
Related Concept Videos
Preparation of Amines: Reductive Amination of Aldehydes and Ketones
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Acid Halides to Amides: Aminolysis
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
Stereochemical Effects of Enolization
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Oxidations of Aldehydes and Ketones to Carboxylic Acids
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...

