Tsutomu Terauchi - Academia.edu (original) (raw)

Papers by Tsutomu Terauchi

PLOS ONE, Aug 2, 2022

Simultaneous imaging of L-dihydroxyphenylalanine (L-DOPA), dopamine (DA) and norepinephrine (NE) ... more Simultaneous imaging of L-dihydroxyphenylalanine (L-DOPA), dopamine (DA) and norepinephrine (NE) in the catecholamine metabolic pathway is particularly useful because L-DOPA is a neurophysiologically important metabolic intermediate. In this study, we found that 2,4,6-trimethylpyrillium tetrafluoroborate (TMPy) can selectively and efficiently react with target catecholamine molecules. Specifically, simultaneous visualization of DA and NE as metabolites of L-DOPA with high steric hinderance was achieved by derivatized-imaging mass spectrometry (IMS). Interestingly, L-DOPA showed strong localization in the brainstem, in contrast to the pattern of DA and NE, which co-localized with tyrosine hydroxylase (TH). In addition, to identify whether the detected molecules were endogenous or exogenous L-DOPA, mice were injected with L-DOPA deuterated in three positions (D 3-L-DOPA), which was identifiable by a mass shift of 3Da. TMPy-labeled L-DOPA, DA and NE were detected at m/z 302.1, 258.1 and 274.1, while their D 3 versions were detected at 305.0, 261.1 and 277.1 in mouse brain, respectively. L-DOPA and D 3-L-DOPA were localized in the BS. DA and NE, and D 3-DA and D 3-NE, all of which are metabolites of L-DOPA and D 3-L-DOPA, were localized in the striatum (STR) and locus coeruleus (LC). These findings suggest a mechanism in the brainstem that allows L-DOPA to accumulate without being metabolized to monoamines downstream of the metabolic pathway.

Proceedings for Annual Meeting of The Japanese Pharmacological Society

Simultaneous imaging of l-dihydroxyphenylalanine (l-DOPA), dopamine (DA) and norepinephrine (NE) ... more Simultaneous imaging of l-dihydroxyphenylalanine (l-DOPA), dopamine (DA) and norepinephrine (NE) in the catecholamine metabolic pathway is particularly useful because l-DOPA is a neurophysiologically important metabolic intermediate. In this study, we found that 2,4,6-trimethylpyrillium tetrafluoroborate (TMPy) can selectively and efficiently react with target catecholamine molecules. Specifically, simultaneous visualization of DA and NE as metabolites of l-DOPA with high steric hinderance was achieved by derivatized-imaging mass spectrometry (IMS). Interestingly, l-DOPA showed strong localization in the brainstem, in contrast to the pattern of DA and NE, which co-localized with tyrosine hydroxylase (TH). In addition, to identify whether the detected molecules were endogenous or exogenous l-DOPA, mice were injected with l-DOPA deuterated in three positions (D 3-l-DOPA), which was identifiable by a mass shift of 3Da. TMPylabeled l-DOPA, DA and NE were detected at m/z 302.1, 258.1 and 274.1, while their D 3 versions were detected at 305.0, 261.1 and 277.1 in mouse brain, respectively. l-DOPA and D 3-l-DOPA were localized in the BS. DA and NE, and D 3-DA and D 3-NE, all of which are metabolites of L-DOPA and D 3-l-DOPA, were localized in the striatum (STR) and locus coeruleus (LC). These findings suggest a mechanism in the brainstem that allows l-DOPA to accumulate without being metabolized to monoamines downstream of the metabolic pathway.

Journal of Back and Musculoskeletal Rehabilitation, 2009

Although both the hydrophobic aliphatic chain and hydrophilic ζ-amino group of the Lys side chain... more Although both the hydrophobic aliphatic chain and hydrophilic ζ-amino group of the Lys side chain presumably contribute to the structures and functions of proteins, the dual nature of the Lys residue has not been fully investigated by NMR spectroscopy, due to the lack of appropriate methods to acquire comprehensive information on its long consecutive methylene chain. We describe herein a robust strategy to address the current situation, using various isotope-aided NMR technologies. The feasibility of our approach is demonstrated for the ∆+PHS/V66K variant of Staphylococcal nuclease (SNase), which contains as many as 21 Lys residues, including the engineered Lys-66 with an unusually low pKa of ~5.6. All of the NMR signals for the 21 Lys residues were sequentially and stereo-specifically assigned by using the stereo-array isotope labeled Lys (SAIL-Lys), [U-13 C, 15 N; β2,γ2,δ2,ε3-D4]-Lys. The unambiguously assigned NMR signals for the β-, γ-, δand ε-methylene moieties afforded a variety of crucial structural information, which could not be obtained by other methods. For example, the 13 C ε signals in the SNase variant, selectively labeled with [ε-13 C; ε,ε-D2]-Lys, were ~0.3 ppm up-field shifted in D2O, as compared to those in H2O, except for Lys-66, which showed a ~0.2 ppm up-field shift in D2O. This result indicates that the deuterium-induced up-field shifts of the 13 C ε signals depend on the ionization states of the ζ-amino group; i.e., ~-0.3 ppm for ∆δ 13 C ε [N ζ D3 +-N ζ H3 + ] and ~-0.2 ppm for ∆δ 13 C ε [N ζ D2-N ζ H2]. Since the highly sensitive 1D-13 C NMR spectrum of a protein selectively labeled with [ε-13 C; ε,ε-D2]-Lys shows extremely narrow, well-dispersed 13 C signals, the deuterium-induced isotope shifts will be a powerful alternative tool to characterize the ionization states of the Lys ζ-amino groups in larger proteins.

Journal of Back and Musculoskeletal Rehabilitation, 2008

Biochimica et Biophysica Acta (BBA) - General Subjects, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of the American Chemical Society, 2019

Aromatic residues are located at structurally important sites of many proteins. Probing their int... more Aromatic residues are located at structurally important sites of many proteins. Probing their interactions and dynamics can provide important functional insight but is challenging in large proteins. Here, we introduce approaches to characterize dynamics of phenylalanine residues using 1 H-detected fast magic-angle spinning (MAS) NMR combined with a tailored isotope-labeling

Journal of biomolecular NMR, Jan 22, 2018

In this perspective, we describe our efforts to innovate the current isotope-aided NMR methodolog... more In this perspective, we describe our efforts to innovate the current isotope-aided NMR methodology to investigate biologically important large proteins and protein complexes, for which only limited structural information could be obtained by conventional NMR approaches. At the present time, it is widely believed that only backbone amide and methyl signals are amenable for investigating such difficult targets. Therefore, our primary mission is to disseminate our novel knowledge within the biological NMR community; specifically, that any type of NMR signals other than methyl and amide groups can be obtained, even for quite large proteins, by optimizing the transverse relaxation properties by isotope labeling methods. The idea of "TROSY by isotope labeling" has been cultivated through our endeavors aiming to improve the original stereo-array isotope labeling (SAIL) method (Kainosho et al., Nature 440:52-57, 2006). The SAIL TROSY methods subsequently culminated in the successf...

Journal of biomolecular NMR, Sep 1, 2016

Conformational isomerization of disulfide bonds is associated with the dynamics and thus the func... more Conformational isomerization of disulfide bonds is associated with the dynamics and thus the functional aspects of proteins. However, our understanding of the isomerization is limited by experimental difficulties in probing it. We explored the disulfide conformational isomerization of the Cys14-Cys38 disulfide bond in bovine pancreatic trypsin inhibitor (BPTI), by performing an NMR line-shape analysis of its Cys carbon peaks. In this approach, 1D (13)C spectra were recorded at small temperature intervals for BPTI samples selectively labeled with site-specifically (13)C-enriched Cys, and the recorded peaks were displayed in the order of the temperature after the spectral scales were normalized to a carbon peak. Over the profile of the line-shape, exchange broadening that altered with temperature was manifested for the carbon peaks of Cys14 and Cys38. The Cys14-Cys38 disulfide bond reportedly exists in equilibrium between a high-populated (M) and two low-populated states (m c14 and m ...

Journal of biomolecular NMR, Jun 6, 2016

We recently developed a practical protocol for preparing proteins bearing stereo-selectively (13)... more We recently developed a practical protocol for preparing proteins bearing stereo-selectively (13)C-methyl labeled leucines and valines, instead of the commonly used (13)C-methyl labeled precursors for these amino acids, by E. coli cellular expression. Using this protocol, proteins with any combinations of isotope-labeled or unlabeled Leu and Val residues were prepared, including some that could not be prepared by the precursor methods. However, there is still room for improvement in the labeling efficiencies for Val residues, using the methods with labeled precursors or Val itself. This is due to the fact that the biosynthesis of Val could not be sufficiently suppressed, even by the addition of large amounts of Val or its precursors. In this study, we completely solved this problem by using a mutant strain derived from E. coli BL21(DE3), in which the metabolic pathways depending on two enzymes, dihydroxy acid dehydratase and β-isopropylmalate dehydrogenase, are completely aborted by...