• 한국자기공명학회논문지
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• 제19권3호
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• pp.112-118
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• 2015

Hsp31 protein is one of the members of DJ-1 superfamily proteins and has a dimeric structure of which molecular weight (MW) is 62 kDa. The mutation of DJ-1 is closely related to early onset of Parkinson's disease. Hsp31 displays $Zn^{+2}$-binding activity and was first reported to be a holding chaperone in E. coli. Its additional glyoxalase III active has recently been characterized. Moreover, an incubation at $60^{\circ}C$ induces Hsp31 protein to form a high MW oligomer (HMW) in vitro, which accomplishes an elevated holding chaperone activity. The NMR technique is elegant method to probe any local or global structural change of a protein in responses to environmental stresses (heat, pH, and metal). Although the presence of the backbone chemical shifts (bbCSs) is a prerequisite for detailed NMR analyses of the structural changes, general HSQC-based triple resonance experiments could not be used for 62 kDa Hsp31 protein. Here, we prepared the per-deuterated Hsp31 and performed the TROSY-based triple resonance experiments for the bbCSs assignment. Here, detailed processes of per-deuteration and the NMR experiments are described for other similar NMR approaches.

• Journal of Power Electronics
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• 제13권3호
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• pp.447-457
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• 2013

For grid-connected LCL-filtered inverters, resonance yields instability and low bandwidth. As a result, careful designs are required. This paper presents a systematic current control structure, where pole assignment consisting of one or more feedbacks is the inner loop, and the outer loop is the direct grid current control. Several other issues are discussed, such as the inner-loop feedback choices, pole-assignment algorithms, robustness and harmonic rejection. Generally, this kind of strategy has three different types according to the inner-loop feedback choices. Among them, a novel pole-assignment algorithm has been proposed, where the inner control maintains four freely-assigned poles which are just two pairs of conjugated poles located at the fundamental and resonance frequencies separately. It has been found that with the different types, the steady-state and dynamic performances are quite different. Finally, simulations and experiments have been provided to verify the control and design of the proposed methods.

• 한국자기공명학회논문지
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• 제19권2호
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• pp.83-87
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• 2015

Syndesmos, which is co-localized with syndecan-4 cytoplasmic domain ($Syn4^{cyto}$) in focal contacts, interacts with various cell adhesion adaptor proteins including $Syn4^{cyto}$ to control cell signaling. Syndesmos consists of 211 amino acids and it exists as a dimer (44kDa) in solution. Recently, we have determined the structure of syndesmos by x-ray crystallography, however, dynamics related to syndecan binding still remain elusive. In this report, we performed NMR experiments to acquire biochemical and structural information of syndesmos. Based on a series of three-dimensional triple resonance experiments on a $^{13}C/^{15}N/^2H$ labeled protein, NMR spectra were obtained with well dispersed and homogeneous NMR data. We present the sequence specific backbone assignment of syndesmos and assigned NMR data with combination structural information can be directly used for the studies on interaction with $Syn4^{cyto}$ and other binding molecules.

• Molecules and Cells
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• 제27권4호
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• pp.493-496
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• 2009

Hypoxia-inducible factor $1{\alpha}$ ($HIF1{\alpha}$) is a transcription factor that plays a key role in the adaptation of cells to low oxygen stress and oxygen homeostasis. The oxygen-dependent degradation (ODD) domain of $HIF1{\alpha}$ responsible for the negative regulation of $HIF1{\alpha}$ in normoxia is intrinsically unfolded. Here, we carried out the backbone $^1H$, $^{15}N$, and $^{13}C$ resonance assignment of a proteolysis-resistant fragment (residues 404-477) in the $HIF1{\alpha}$ ODD domain using NMR spectroscopy. About 98% (344/352) of all the $^1HN$, $^{15}N$, $^{13}C{\alpha}$, $^{13}C{\beta}$, and $^{13}CO$ resonances were unambiguously assigned. The results will be useful for further investigation of the structural and dynamic states of the $HIF1{\alpha}$ ODD domain and its interaction with binding partners.

• 한국자기공명학회논문지
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• 제28권2호
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• pp.6-9
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• 2024

HscA is a Hsp70-type chaperone protein that plays an essential role to mediate the iron-sulfur (Fe-S) cluster biogenesis mechanism in Escherichia coli. Like other Hsp70 chaperones, HscA is composed of two domains: the nucleotide binding domain (NBD), which can hydrolyze ATP and use its chemical energy to facilitate the Fe-S cluster transfer process, and the substrate binding domain (SBD), which directly interacts with the substrate, IscU, the scaffold protein of an Fe-S cluster. In the present work, we prepared the isolated SBD construct of HscA (HscA(SBD)) and conducted the solution-state nuclear magnetic resonance (NMR) experiments to have its backbone chemical shift assignment information. Due to low spectral quality of HscA(SBD), we obtained all the NMR data from the sample containing the peptide LPPVKIHC, the HscA-interaction motif of IscU, from which the chemical shift assignment could be done successfully. We expect that this information provides an important basis to execute detailed structural characterization of HscA and appreciate its interaction with IscU.

• 한국자기공명학회논문지
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• 제21권1호
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• pp.20-25
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• 2017

The cytoplasmic domains A and B of the mannitol transporter enzyme $II^{Mtl}$ are covalently linked in Escherichia coli, but separately expressed in Thermoanaerobacter Tengcongensis. The phosphorylation of domain B ($TtIIB^{Mtl}$) substantially increases the binding affinity to the domain A ($TtIIA^{Mtl}$) in T. Tengcongensis. To understand the structural basis of the enhanced domain-domain interaction by protein phosphorylation, we obtained NMR backbone assignments of the phospho-$TtIIB^{Mtl}$ using a standard suite of triple resonance experiments. Our results will be useful to monitor chemical shift changes at the active site of phosphorylation and the binding interfaces.

• 한국자기공명학회논문지
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• 제20권2호
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• pp.50-55
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• 2016

Backbone $^1H$, $^{13}C$ and $^{15}N$ resonance assignments are presented for the anticodon binding domain (residues 557-674) of human glycyl-tRNA synthetase (GRS). Role of the anticodon binding domain (ABD) of GRS as an anticancer ligand has recently been reported and its role in other diseases like Charcot-Marie-Tooth (CMT) and polymyositis have increased its interest. NMR assignments were completed using the isotope [$^{13}C/^{15}N$]-enriched protein and chemical shifts based secondary structure analysis with TALOS+ demonstrate similar secondary structure as reported in X-ray structure PDB 2ZT8, except some C-terminal residues. NMR signals from the N-terminal residues 557 to 571 and 590 to 614 showed very weak or no signals exhibiting dynamics or conformational exchange in NMR timescale.

• 한국자기공명학회논문지
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• 제19권1호
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• pp.42-48
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• 2015

The mannitol transporter Enzyme $II^{Mtl}$ of the bacterial phosphotransferase system has two cytoplasmic phosphoryl transfer domains $IIA^{Mtl}$ and $IIB^{Mtl}$. The two domains are linked by a flexible peptide linker in mesophilic bacterial strains, whereas they are expressed as separated domains in thermophilic strains. Here, we carried out backbone assignment of $IIA^{Mtl}$ from thermophilic Thermoanaerobacter Tencongensis using a suite of heteronuclear triple resonance NMR spectroscopy. We have completed 94% of the backbone assignment, and obtained secondary structural information based on torsion angles derived from the chemical shifts. $IIA^{Mtl}$ of Thermoanaerobacter Tencongensis is predicted to have six ${\beta}$ strands and six ${\alpha}$ helices, which is analogous to $IIA^{Mtl}$ of Escherichia coli.

• 한국자기공명학회논문지
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• 제25권1호
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• pp.8-11
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• 2021

Transthyretin (TTR) is an important transporter protein for thyroxine (T4) and a holo-retinol protein in human. In its native state, TTR forms a tetrameric complex to construct the hydrophobic binding pocket for T4. On the other hand, this protein is also infamous for its amyloidogenic propensity, which causes various human diseases, such as senile systemic amyloidosis and familial amyloid polyneuropathy/cardiomyopathy. In this work, to investigate various structural features of TTR with solution-state nuclear magnetic resonance (NMR) spectroscopy, we conducted backbone NMR signal assignments. Except the N-terminal two residues and prolines, backbone 1H-15N signals of all residues were successfully assigned with additional chemical shift information of 13CO, 13Cα, and 13Cβ for most residues. The chemical shift information reported here will become an important basis for subsequent structural and functional studies of TTR.

• 한국자기공명학회논문지
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• 제27권3호
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• pp.17-22
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• 2023

Bloom syndrome protein (BLM) is a pivotal RecQ helicase necessary for genetic stability through DNA repair processes. Our investigation focuses on the N-terminal region of BLM, which has been considered as an intrinsically disordered region (IDR). This IDR plays a critical role in DNA metabolism by interacting with other proteins. In this study, we performed triple resonance experiments of BLM_220-300 and presented the backbone chemical shifts. The secondary structure prediction based on chemical shifts of the backbone atoms shows the region is disordered. Our data could help further interaction studies between BLM_220-300 and its binding partners using NMR.