Crystal structure of the EnvZ periplasmic domain with CHAPS

Hwang, Eunha,Cheong, Hae-Kap,Kim, Sang-Yoon,Kwon, Ohsuk,Blain, Katherine Y.,Choe, Senyon,Yeo, Kwon Joo,Jung, Yong Woo,Jeon, Young Ho,Cheong, Chaejoon North-Holland Pub 2017 FEBS letters Vol. No.

<P>Bacteria sense and respond to osmolarity through the EnvZ-OmpR two-component system. The structure of the periplasmic sensor domain of EnvZ (EnvZ-PD) is not available yet. Here, we present the crystal structure of EnvZ-PD in the presence of CHAPS detergent. The structure of EnvZ-PD shows similar folding topology to the PDC domains of PhoQ, DcuS, and CitA, but distinct orientations of helices and beta-hairpin structures. The CD and NMR spectra of EnvZ-PD in the presence of cholate, a major component of bile salts, are similar to those with CHAPS. Chemical cross-linking shows that the dimerization of EnvZ-PD is significantly inhibited by the CHAPS and cholate. Together with beta-galactosidase assay, these results suggest that bile salts may affect the EnvZ structure and function in Escherichia coli.</P>

Solution Structure and Backbone Dynamics of the Biotinylation Domain of Helicobacter pylori Biotin-carboxyl Carrier Protein

정진원,이철진,전영호,이원태,Chaejoon Cheong 대한화학회 2008 Bulletin of the Korean Chemical Society Vol.29 No.2

Acetyl-CoA carboxylase (ACC) is an excellent candidate for antibiotics drug target, which mediates malonyl-CoA synthesis from acetyl-CoA through acetylation process. It is also involved in the committed step of fatty acid synthesis which is essential for living organisms. We have determined the three dimensional structure of C terminal domain of HP0371, biotin-carboxyl carrier protein of H. pyroli, in solution state using heteronuclear multi-dimensional NMR spectroscopy. The structure of HP0371 shows a flatten b-sheet fold which is similar with that of E. coli. However, the sequence and structure of protruding thumb are different with that of E. coli and the thumb shows different basis of structural rigidity based on backbone dynamics data.

Biotinoyl domain of human acetyl-CoA carboxylase: Structural insights into the carboxyl transfer mechanism

Lee, Chung-Kyung,Cheong, Hae-Kap,Ryu, Kyoung-Seok,Lee, Jae Il,Lee, Weontae,Jeon, Young Ho,Cheong, Chaejoon Wiley Subscription Services, Inc., A Wiley Company 2008 Proteins Vol.72 No.2

<P>Acetyl-CoA carboxylase (ACC) catalyzes the first step in fatty acid biosynthesis: the synthesis of malonyl-CoA from acetyl-CoA. As essential regulators of fatty acid biosynthesis and metabolism, ACCs are regarded as therapeutic targets for the treatment of metabolic diseases such as obesity. In ACC, the biotinoyl domain performs a critical function by transferring an activated carboxyl group from the biotin carboxylase domain to the carboxyl transferase domain, followed by carboxyl transfer to malonyl-CoA. Despite the intensive research on this enzyme, only the bacterial and yeast ACC structures are currently available. To explore the mechanism of ACC holoenzyme function, we determined the structure of the biotinoyl domain of human ACC2 and analyzed its characteristics and interaction with the biotin ligase, BirA using NMR spectroscopy. The 3D structure of the hACC2 biotinoyl domain has a similar folding topology to the earlier determined domains from E. coli and P. shermanii. However, the local structures near the biotinylation sites have notable differences that include the geometry of the consensus “Met-Lys-Met” (MKM) motif and the absence of “thumb” structure in the hACC2 biotinoyl domain. Observations of the NMR signals upon the biotinylation indicate that the biotin group of hACC2 does not affect the structure of the biotinoyl domain, while the biotin group for E. coli ACC interacts directly with the thumb residues that are not present in the hACC2 structure. These results imply that, in the E. coli ACC reaction, the biotin moiety carrying the carboxyl group from BC to CT can pause at the thumb of the BCCP domain. The human biotinoyl domain, however, lacks the thumb structure and does not have additional noncovalent interactions with the biotin moiety; thus, the flexible motion of the biotinylated lysine residue must underlie the “swinging arm” motion. The chemical shift perturbation and the cross saturation experiments of the human ACC2 holo-biotinoyl upon the addition of the biotin ligase (BirA) showed the interaction surface near the MKM motif, the two glutamic acids (Glu 926, Glu 953), and the positively charged residues (several lysine and arginine residues). This study provides insight into the mechanism of ACC holoenzyme function and supports the swinging arm model in human ACCs. Proteins 2008. © 2008 Wiley-Liss, Inc.</P>

Neural Pathways in Anger Processing: A Dynamic Causal Modeling Study

Ji-Woo Seok,Chaejoon Cheong,Young-Ji Eum 대한인간공학회 2017 대한인간공학회 학술대회논문집 Vol.2017 No.4

The N-terminal domain of human holocarboxylase synthetase facilitates biotinylation via direct interaction with the substrate protein

Lee, Chung-Kyung,Cheong, Chaejoon,Jeon, Young Ho Elsevier 2010 FEBS letters Vol.584 No.4

<P><B>Abstract</B></P><P>Human holocarboxylase synthetase shows a high degree of sequence homology in the catalytic domain with bacterial biotin ligases such as <I>Escherichia coli</I> BirA, but differs in the length and sequence of the N-terminus. Despite several studies having been undertaken on the N-terminal region of hHCS, the role of this region remains unclear. We determined the structure of the N-terminal domain of hHCS by limited proteolysis and showed that this domain has a crucial effect on the enzymatic activity. The domain interacts not only with biotin acceptor protein, but also with the catalytic domain of hHCS, as shown by nuclear magnetic resonance (NMR) experiments. We propose that the N-terminal domain of hHCS recognizes the charged region of biotin acceptor protein, distinctly from the recognition by the catalytic domain.</P><P><B>Structured summary</B></P><P>MINT-7543113: <I>hHCS</I> (uniprotkb:P50747) and <I>hHCS</I> (uniprotkb:P50747) <I>bind</I> (MI:0407) by <I>nuclear magnetic resonance</I> (MI:0077)</P><P>MINT-7543096, MINT-7543129: <I>ACC75</I> (uniprotkb:O00763) and <I>hHCS</I> (uniprotkb:P50747) <I>bind</I> (MI:0407) by <I>nuclear magnetic resonance</I> (MI:0077)</P><P>MINT-7543053: <I>hHCS</I> (uniprotkb:P50747) <I>enzymaticly reacts</I> (MI:0414) <I>ACC75</I> (uniprotkb:O00763) by <I>nuclear magnetic resonance</I> (MI:0077)</P><P>MINT-7543070: <I>hHCS</I> (uniprotkb:P50747) <I>enzymaticly reacts</I> (MI:0414) <I>ACC75</I> (uniprotkb:O00763) by <I>enzymatic study</I> (MI:0415)</P>

Berenil과 $d(CGTATACG)_2$ Duplex의 결합에 관한 핵자기공명연구

허성호,김은희,정재준,Huh, Sungho,Kim, Eunhee,Cheong, Chaejoon 대한화학회 1997 대한화학회지 Vol.41 No.10

1H, 15N and 13C Backbone Assignments and Secondary Structures of C-ter100 Domain of Vibrio Extracellular Metalloprotease Derived from Vibrio vulnificus

윤지혜,Heeyoun Kim,박정은,Hae-kap Cheong,Chaejoon Cheong,Jung Sup Lee,이원태 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

Vibrio extracellular metalloprotease (vEP), secreted from Vibrio vulnificus, shows various proteolytic function such as prothrombin activation and fibrinolytic activities. Premature form of vEP has an N-terminal (nPP) and a C-terminal (C-ter100) region. The nPP and C-ter100 regions are autocleaved for the matured metalloprotease activity. It has been proposed that two regions play a key role in regulating enzymatic activity of vEP. Especially, C-ter100 has a regulatory function on proteolytic activity of vEP. C-ter100 domain has been cloned into the E. coli expression vectors, pET32a and pGEX 4T-1 with TEV protease cleavage site and purified using gel-filtration chromatography followed by affinity chromatography. To understand how C-ter100 modulates proteolytic activity of vEP, structural studies were performed by heteronuclar multi-dimensional NMR spectroscopy. Backbone 1H, 15N and 13C resonances were assigned by data from standard triple resonance and HCCH-TOCSY experiments. The secondary structures of vEP C-ter100 were determined by TALOS+ and CSI software based on hydrogen/deuterium exchange. NMR data show that C-ter100 of vEP forms a β-barrel structure consisting of eight β-strands.

Neural substrates of sexual arousal in heterosexual males: event-related fMRI investigation

Seok, Ji-Woo,Sohn, Jin-Hun,Cheong, Chaejoon BioMed Central 2016 Journal of Physiological Anthropology Vol.35 No.1

<P><B>Background</B></P><P>Sexual behavior is an important role for the survival of species. The advancement of brain imaging methods has enabled the understanding of the brain mechanism related to sexual arousal. The previous studies on the brain mechanism related to sexual arousal have mostly conducted on block design paradigm.</P><P><B>Methods</B></P><P>Despite its requirement for stricter experimental control, the event-related paradigm is known to be more efficient in detecting instant emotional and cognitive responses. The paradigm also enables the observation of hemodynamic responses through time. Therefore, this study used the event-related fMRI to examine the brain activation in various areas associated with sexual arousal as well as changes in hemodynamic responses with time.</P><P><B>Results</B></P><P>Strong activations were observed in the various areas associated with sexual arousal comprised of various factors: (1) activation areas related to cognitive factors: the occipital lobe and parietal lobe; (2) activation areas related to emotional factors: the thalamus and amygdala; (3) activation areas related to motivational factors: the anterior cingulate gyrus, orbitofrontal cortex, and insula; and (4) activation areas related to physiological factors: the precentral gyrus, putamen, and globus pallidus. We also identified the activation of the putamen and globus pallidus that were not well observed in previous block design studies. In the result of the hemodynamic response, the neural activity in those areas showed more transient aspects of the hemodynamic responses relative to the neural activity of other areas.</P><P><B>Conclusions</B></P><P>These results suggested that the event-related paradigm is better at detecting the neural activity of the brain regions, which tend to appear suddenly, but disappear soon.</P>

주요우울 장애자의 얼굴 정서 인식 동안에 나타난 뇌 기능 특성

박미숙(Mi-Sook Park),정재준(Chaejoon Cheong),손진훈(Jin-Hun Sohn) 대한인간공학회 2019 大韓人間工學會誌 Vol.38 No.5

Objective: The aim of this study is to investigate neural correlates of facial emotion recognition among individuals with major depressive disorders (MDD). Background: Major depression is one of the most fatal diseases in the world and is estimated to be the second largest disease burden by 2020 (WHO, 2001). Despite the increasing number studies on the emotion recognition in MDD, neural underpinning of facial emotion recognition in MDD is not still clear. Method: Twelve individuals with MDD and demographically matched 7 controls participated in the study. Facial recognition task was used for the study and face stimuli were selected from KUFEC (Korea University Facial Expression Collection). Functional images were scanned while recognizing the facial expressions of happiness, sadness, and anger on Phillips 3.T scanner. Imaging data were analyzed by using SPM 8. Results: There was no group difference while the individuals with MDD were recognizing the sad and angry expressions in the face compared with the controls. In the fMRI result, there was no group difference of brain activity between the two groups during the sad and angry processing. However, during the recognition of happiness, MDD participants made more errors than the controls. In the fMRI result, MDD participants showed greater activation in the middle frontal gyrus, insula, and putamen during the happiness recognition. Conclusion: Impairment of happiness recognition among MDD participants was related to hyperactivation in the inferior gyrus, insular, and putamen, known to be responsible for regulatory processes and emotional salience. Application: The brain substrates associated with emotional processing among individuals with depression is still important and essential for the development of new therapies for depression. The results on the neural correlates of facial expressions of emotion might help to develop new therapy for depression that target the specific brain regions.

Dynamics of d(CGAATTCG)_(2) and d(CGTATACG)_(2) duplexes and their berenil complexes

Hong, Seokju,Huh, Sungho,Kim, Eunhee,Cheong, Chaejoon 충남대학교 기초과학연구소 1999 忠南科學硏究誌 Vol.26 No.1

We prepared two oligonucleotides having Same base pairing but different base sequence in the middle region, d(CGAATTCG) and d(CGTATACG). NMR and UV data showed that such variation in base sequence caused significant differences in thermal stability and dynamics, which is regarded to be associated with the base-sequence specificity on binding interaction between DNA and ligands.