Screening mixtures for biological activity by NMR

Area of Science:

• Biochemistry
• Structural Biology
• Analytical Chemistry

Background:

• Drug development relies on screening compound libraries for biological activity.
• Identifying active compounds in mixtures is challenging, typically requiring pure compounds or spatial separation.
• Current methods limit the efficiency of screening complex mixtures for bioactive molecules.

Purpose of the Study:

• To present a novel nuclear magnetic resonance (NMR) technique based on the transferred nuclear Overhauser effect (transfer NOE).
• To enable the identification and structural characterization of biologically active molecules directly from mixtures.
• To enhance the capabilities for screening compound libraries in drug discovery.

Main Methods:

• Utilized the transferred nuclear Overhauser effect (transfer NOE) NMR technique.
• Applied the method to mixtures of oligosaccharides to identify binding components.
• Analyzed the sign and intensity of transfer NOEs for unequivocal identification of binders.

Main Results:

• Successfully identified alpha-L-Fuc-(1-->6)-beta-D-GlcNAc-OMe as the sole binding component in an oligosaccharide mixture with Aleuria aurantia agglutinin.
• Demonstrated that the sign of transferred NOEs is opposite for binding vs. non-binding molecules.
• Observed significantly greater absolute intensity for transfer NOEs of bound ligands compared to non-bound molecules.

Conclusions:

• The transfer NOE NMR technique allows for unambiguous identification of biologically active molecules within mixtures.
• This method provides valuable information on the three-dimensional structure of ligands in their bound state.
• Measuring transfer NOEs in mixtures significantly expands options for screening compounds for biological activity, aiding drug discovery.