Substrate-Specific Amino Acid Sensing Using a Molecular d/l-Cysteine Probe for Comprehensive Stereochemical Analysis in Aqueous Solution

Angewandte Chemie - International Edition

5 years ago

Substrate-Specific Amino Acid Sensing Using a Molecular d/l-Cysteine Probe for Comprehensive Stereochemical Analysis in Aqueous Solution

F. Yushra Thanzeel, Christian Wolf

The appearance of d-amino acids in mammals and humans has important implications in the life sciences. d/l-Amino acid mixtures play a key role in human physiology and pathology; thus, the introduction of artificial receptors for the real-time quantification of both the concentration and d/l composition of amino acids is very promising for the study of biological processes and for the diagnosis and treatment of diseases. We now report a sensing assay that is compatible with aqueous solutions and allows fast determination of the absolute configuration, enantiomeric composition, and overall amount of cysteine at micromolar concentrations. The method relies on fast UV and CD measurements, which provide accurate stereochemical information on samples covering a wide concentration range and drastically different d/l-cysteine ratios in simulated body fluids. Competition experiments show that other amino acids and biothiols do not interfere with the cysteine-targeted sensing. A chiroptical sensing assay allows the real-time optical sensing of nonracemic d/l-cysteine in the presence of other amino acids and biothiols. It is compatible with aqueous solutions and allows fast determination of the absolute configuration, ee value, and overall amount of cysteine at micromolar concentrations and in simulated body fluids. Other amino acids, homocysteine, and glutathione do not interfere with the cysteine-targeted sensing.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/anie.201701188