Change search
ReferencesLink to record
Permanent link

Direct link
Reversed Enantiopreference of an omega-Transaminase by a Single-Point Mutation
KTH, School of Biotechnology (BIO), Biochemistry.ORCID iD: 0000-0003-2371-8755
KTH, School of Biotechnology (BIO), Biochemistry.ORCID iD: 0000-0002-9577-832X
2010 (English)In: CHEMCATCHEM, ISSN 1867-3880, Vol. 2, no 8, 976-980 p.Article in journal (Refereed) Published
Abstract [en]

Altering the characteristics of an active-site loop in an (S)-selective omega-transaminase from Arthrobacter citreus (variant CNB05-01) influences the enantioselectivity. This active-site loop belongs to the second subunit of the dimeric enzyme structure that participates in the coordination of pyridoxal-5'-phosphate (PLP) in the so called "phosphate group binding cup". Three amino acid residues (E326, V328, and Y331) in this loop are selected by homology modeling for site-directed mutagenesis aiming to increase the enzyme enantioselectivity for 4-fluorophenylacetone. By combining these mutations, five enzyme variants are created. The performance of these variants is explored using a model system consisting of isopropylamine and 4-fluorophenylacetone or 4-nitroacetophenone in asymmetric synthesis using a whole-cell system approach. Three of the five variants show increased enantioselectivity for 4-fluorophenylacetone compared to CNB05-01. Variant CNB05-01/Y331C increases the enantioselectivity from 98% ee to over 99.5% ee. A single-point mutation, V328A, turn the (S)-selective omega-transaminase into an (R)-selective enzyme. This switch in enantioselectivity is substrate dependent, exhibiting (R) selectivity for 4-fluorophenylacetone and retaining (S) selectivity for 4-nitroacetophenone. The shift in enantiopreference is further confirmed by molecular docking simulations. Homology modeling is shown to be a powerful tool to target important amino acid residues in this enzyme in order to improve enantioselectivity by rational design.

Place, publisher, year, edition, pages
2010. Vol. 2, no 8, 976-980 p.
Keyword [en]
amines, asymmetric synthesis, enantioselectivity, enzymes, rational design
National Category
Biochemistry and Molecular Biology
URN: urn:nbn:se:kth:diva-26834DOI: 10.1002/cctc.201000107ISI: 000281321700013ScopusID: 2-s2.0-79957694192OAI: diva2:374790
QC 20101206Available from: 2010-12-06 Created: 2010-11-29 Last updated: 2010-12-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Svedendahl, MariaBerglund, Per
By organisation
Biochemistry and Molecular Biology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 54 hits
ReferencesLink to record
Permanent link

Direct link