The University of Tokyo · Biochemistry, Genetics and Molecular Biology
Professor Masaru Tanokura's research lab specializes in structural and physical biochemistry, with a strong focus on the application of nuclear magnetic resonance (NMR) spectroscopy to study biomolecular interactions and dynamics. The lab investigates the conformational behavior and pKa properties of ionizable groups in peptides and proteins, particularly histidine residues, using advanced NMR titration and curve-fitting techniques. Additionally, the lab develops and applies sophisticated NMR methodologies for the analysis of complex natural product mixtures, such as green coffee bean extract, enabling the identification, quantification, and structural elucidation of multiple compounds without prior separation. Their work bridges analytical chemistry and molecular biology, contributing to both fundamental understanding and practical applications in biochemistry and natural product analysis.
Figures are computed from collected data and may differ slightly.
Abstract The nmr titration curves of chemical shifts versus pH were observed for the protons of various histidine‐containing di‐ and tripeptides. With these results, the macroscopic p K a values and the chemical shifts intrinsic to each ionic species were determined by a computer curve‐fitting based on a simple acid dissociation sequence. The p K a value of the imidazole ring in N ‐acetyl‐ L ‐histidine methylamide was assumed to represent the intrinsic (or unperturbed) p K a of the imidazole rin
The binding of the chymotryptic troponin T subfragments to tropomyosin, troponin I, and troponin C was semiquantitatively examined by using affinity chromatography, and also by co-sedimentation with F-actin and polyacrylamide gel electrophoresis in 14 mM Tris/90 mM glycine. Circular dichroism spectra of the subfragments were measured to confirm that the subfragments retained their conformational structures. Based on these results, the binding sites of tropomyosin, troponin I, and troponin C on t
A complex mixture analysis by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy was carried out for the first time for the identification and quantification of organic compounds in green coffee bean extract (GCBE). A combination of (1)H-(1)H DQF-COSY, (1)H-(13)C HSQC, and (1)H-(13)C CT-HMBC two-dimensional sequences was used, and 16 compounds were identified. In particular, three isomers of caffeoylquinic acid were identified in the complex mixture without any separation. In
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