Non-alpha-hydroxylated aldehydes with evolved transketolase enzymes

Area of Science:

• Biocatalysis
• Enzyme Engineering
• Organic Chemistry

Background:

• Transketolase (TK) is an enzyme involved in the pentose phosphate pathway.
• Engineered TK variants have shown promise for stereoselective synthesis.
• Previous TK mutants were optimized for non-phosphorylated aldehydes like propanal.

Purpose of the Study:

• To investigate the substrate scope of previously identified transketolase mutants.
• To evaluate the stereoselectivity of these mutants with a broader range of aliphatic aldehydes.
• To assess the potential of these engineered enzymes in asymmetric synthesis.

Main Methods:

• Utilized previously engineered transketolase mutants.
• Tested enzyme activity and stereoselectivity with a series of linear and cyclic aliphatic aldehydes.
• Analyzed reaction products to determine enantiomeric excess (ee) and diastereomeric excess (de).

Main Results:

• Transketolase mutants exhibited high stereoselectivity across a range of tested aliphatic aldehydes.
• Excellent stereoselectivities were observed, indicating broad applicability.
• The enzyme variants demonstrated effectiveness with both linear and cyclic aldehyde substrates.

Conclusions:

• Engineered transketolase mutants possess a wider substrate scope than initially determined.
• These mutants are valuable tools for achieving high stereoselectivity in reactions with diverse aliphatic aldehydes.
• The findings support the use of engineered transketolases in stereoselective biocatalytic applications.