http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Unique Unfoldase/Aggregase Activity of a Molecular Chaperone Hsp33 in its Holding-Inactive State
Jo, Ku-Sung,Kim, Ji-Hun,Ryu, Kyoung-Seok,Kang, Joo-Seong,Wang, Chae-Yeon,Lee, Yoo-Sup,Seo, Min-Duk,Lee, Young-Ho,Won, Hyung-Sik Academic Press 2019 Journal of molecular biology Vol.431 No.7
<P><B>Abstract</B></P> <P>The various chaperone activities of heat shock proteins contribute to ensuring cellular proteostasis. Here, we demonstrate the non-canonical unfoldase activity as an inherent functionality of the prokaryotic molecular chaperone, Hsp33. Hsp33 was originally identified as a holding chaperone that is post-translationally activated by oxidation. However, in this study, we verified that the holding-inactive reduced form of Hsp33 (<SUP>R</SUP>Hsp33) strongly bound to the translational elongation factor, EF-Tu. This interaction was critically mediated by the redox-switch domain of <SUP>R</SUP>Hsp33 and the guanine nucleotide-binding domain of EF-Tu. The bound <SUP>R</SUP>Hsp33, without undergoing any conformational change, catalyzed the EF-Tu aggregation by evoking the aberrant folding of EF-Tu to expose hydrophobic surfaces. Consequently, the oligomers/aggregates of EF-Tu, but not its functional monomeric form, were highly susceptible to proteolytic degradation by Lon protease. These findings present a unique example of an ATP-independent molecular chaperone with distinctive dual functions—as an unfoldase/aggregase and as a holding chaperone—depending on the redox status. It is also suggested that the unusual unfoldase/aggregase activity of <SUP>R</SUP>Hsp33 can contribute to cellular proteostasis by dysregulating EF-Tu under heat-stressed conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hsp33 was originally identified as an oxidation-dependent holding chaperone. </LI> <LI> Holding-inactive reduced form of Hsp33 (<SUP>R</SUP>Hsp33) specifically interacted with EF-Tu. </LI> <LI> <SUP>R</SUP>Hsp33-bound EF-Tu underwent an unfolding, leading to oligomerization/aggregation. </LI> <LI> EF-Tu oligomers/aggregates became susceptible to degradation by Lon protease. </LI> <LI> Aggregase activity of <SUP>R</SUP>Hsp33 can contribute to proteostasis by dysregulating EF-Tu. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>
Gon-Sup Kim , Arulkumar Nagappan, Hyeon-Soo Park, Kwang-Il Park, Jin-A Kim, Gyeong-Eun Hong, Silvia Yumnam, Eun-Hee Kim, Won-Sup Lee, Wang-Jae Lee, Myung-Je Cho, Woo-Kon Lee, Chung-Kil Won 충북대학교 동물의학연구소 2013 Journal of Biomedical and Translational Research Vol.14 No.2
Vitamin C (ascorbic acid) is an essential nutrient of most living tissues. We established a strain of Gulo-/- mice with known deficiency, in which vitamin C intake can be controlled by diet, like humans, and investigated the differentially expressed proteins following treatments with Helicobacter pylori and diethylnitrosamine (DENA) in the liver of Gulo-/- mice using a proteomic approach. Expression of p53, 14-3-3ε and 14-3-3δ in Gulo-/- mice liver tissue was analyzed by immunohistochemistry. 2-DE maps constructed from Gulo-/- mice liver and differentially expressed proteins in liver tissue were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF/MS). In Gulo-/- mice after H. Pylori infection, followed by treatment with DENA, no differences in p53, 14-3-3ε and 14-3-3δ were observed by immunohistochemistry. Proteome analyses using MALDI-TOF/MS resulted in successful identification of 12 proteins (nine proteins were up-regulated and three were down-regulated). Specifically, peroxiredoxin-6 and Alpha-1-antitrypsin 1-4 were up-regulated in liver after H. Pylori infection followed by treatment with DENA. These results indicated that oral supplementation with vitamin C led to rescue of Gulo-/- mice from vitamin deficiency, and protected the liver from H.pylori infection and/or DENA effect, and vitamin C also protected the liver against oxidative stress
JeeYoung Kim,Minho Lee,Min Kyoung Lee,Sheng-Min Wang,Nak-Young Kim,Dong Woo Kang,Yoo Hyun Um,Hae-Ran Na,Young Sup Woo,Chang Uk Lee,Won-Myong Bahk,Donghyeon Kim,Hyun Kook Lim 대한신경정신의학회 2021 PSYCHIATRY INVESTIGATION Vol.18 No.1
Objective Alzheimer’s disease (AD) is the most common type of dementia and the prevalence rapidly increased as the elderly population increased worldwide. In the contemporary model of AD, it is regarded as a disease continuum involving preclinical stage to severe dementia. For accurate diagnosis and disease monitoring, objective index reflecting structural change of brain is needed to correctly assess a patient’s severity of neurodegeneration independent from the patient’s clinical symptoms. The main aim of this paper is to develop a random forest (RF) algorithm-based prediction model of AD using structural magnetic resonance imaging (MRI). Methods We evaluated diagnostic accuracy and performance of our RF based prediction model using newly developed brain segmentation method compared with the Freesurfer’s which is a commonly used segmentation software. Results Our RF model showed high diagnostic accuracy for differentiating healthy controls from AD and mild cognitive impairment (MCI) using structural MRI, patient characteristics, and cognitive function (HC vs. AD 93.5%, AUC 0.99; HC vs. MCI 80.8%, AUC 0.88). Moreover, segmentation processing time of our algorithm (<5 minutes) was much shorter than of Freesurfer’s (6-8 hours). Conclusion Our RF model might be an effective automatic brain segmentation tool which can be easily applied in real clinical practice.
( Shujie Wang ),( Anlin Zhu ),( Suresh Paudel ),( Choon-gon Jang ),( Yong Sup Lee ),( Kyeong-man Kim ) 한국응용약물학회 2023 Biomolecules & Therapeutics(구 응용약물학회지) Vol.31 No.2
Among 14 subtypes of serotonin receptors (5-HTRs), 5-HT<sub>2A</sub>R plays important roles in drug addiction and various psychiatric disorders. Agonists for 5-HT<sub>2A</sub>R have been classified into three structural groups: phenethylamines, tryptamines, and ergolines. In this study, the structure-activity relationship (SAR) of phenethylamine and tryptamine derivatives for binding 5-HT<sub>2A</sub>R was determined. In addition, functional and regulatory evaluation of selected compounds was conducted for extracellular signal-regulated kinases (ERKs) and receptor endocytosis. SAR studies showed that phenethylamines possessed higher affinity to 5-HT<sub>2A</sub>R than tryptamines. In phenethylamines, two phenyl groups were attached to the carbon and nitrogen (R<sup>3</sup>) atoms of ethylamine, the backbone of phenethylamines. Alkyl or halogen groups on the phenyl ring attached to the β carbon exerted positive effects on the binding affinity when they were at para positions. Oxygen-containing groups attached to R<sup>3</sup> exerted mixed influences depending on the position of their attachment. In tryptamine derivatives, tryptamine group was attached to the β carbon of ethylamine, and ally groups were attached to the nitrogen atom. Oxygen-containing substituents on large ring and alkyl substituents on the small ring of tryptamine groups exerted positive and negative influence on the affinity for 5-HT<sub>2A</sub>R, respectively. Ally groups attached to the nitrogen atom of ethylamine exerted negative influences. Functional and regulatory activities of the tested compounds correlated with their affinity for 5-HT<sub>2A</sub>R, suggesting their agonistic nature. In conclusion, this study provides information for designing novel ligands for 5-HT<sub>2A</sub>R, which can be used to control psychiatric disorders and drug abuse.
유동층연소로에서 granulation에 의한 미세입자의 연소효율 향상
김성현,오광중,홍성창,도동섭,차왕석 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.6
내경 0.109 m, 높이 1.8 m인 유동층연소로에서 미세입자가 포함된 다입자계의 granulation 실험을 수행하였다. 미세입자의 집괴입상화와 유동차특성은 압력요동, 연소효율, 온도분포 및 평균입자크기로서 해석하였으며 granulation mechanism은 SEM 분석을 통해 조사하였다. 염과 석탄의 혼합연소시 비유동화가 일어나며 이러한 비유동화현상에 대한 정보를 압력요동신호와 온도분포로부터 알 수 있었다. 유출부에서의 연소효율은 미세입자의 집괴에 의해 3-4배 증가하였고 층내의 granulation mechanism은 agglomeration model임을 알 수 있었다. Granulation experiment was carried out in a 0.109 m ID, 1.8 m height fluidized bed combustor of the multi-sized particles. Granulation of fine coal particles and fluidizing characteristics were investigated by the pressure fluctuations, combustion efficiency, temperature profile and mean particle diameter. Granulation mechanism was studied by the SEM analysis. Defluidization occurred in the mixed firing of salt and anthracite coal and the information on the defluidization phenomena was interpreted with the pressure fluctuation signals and temperature profile. It was found that the combustion efficiency in the elutriated stream was increased 3-4 times by the granulation of fine coal particles and that the granulation mechanism was agglomeration model.
π AND OTHER FORMULAE IMPLIED BY HYPERGEOMETRIC SUMMATION THEOREMS
KIM, YONG SUP,RATHIE, ARJUN KUMAR,WANG, XIAOXIA Korean Mathematical Society 2015 대한수학회논문집 Vol.30 No.3
By employing certain extended classical summation theorems, several surprising ${\pi}$ and other formulae are displayed.
다발성 신경근신경병증과 뇌출혈을 동반한 과호산구성 증후군 1 예
김영훈,이상무,이성배,이현석,송창섭,김혜랑,왕길상,이근만 대한내과학회 1998 대한내과학회지 Vol.55 No.6
Clinical criteria have established for idiopathic hypereosinophilic syndrome(HES): persistent eosinophilia of 1500 eosinophils/㎣ for at least 6 months or death even within 6 months with signs and symptoms of HES; no evidence for parasitic, allergic, or other recognized causes of eosinophilia despite careful evaluation; and signs and symptoms of organ system involvement or dysfunction, such as congestive heart failure, hepatosplenomegaly, central nerveous system disease. Because cerebral hemorrhage in HES has not been reported yet in Korea, we report a case of hypereosinophilic syndrome with peripheral blood eosinophilia, with biopsies of skin and duodenum showing diffuse eosinophilic infiltration, and multiple organ dysfunction in a 49 year old man died of cerebral hemorrhage three months after the occurrence of the disease.
Wang, Hee Ryung,Woo, Young Sup,Ahn, Hyeong Sik,Ahn, Il Min,Kim, Hyun Jung,Bahk, Won-Myong Oxford University Press 2015 International Journal of Neuropsychopharmacology Vol.18 No.8
<P><B>Background:</B></P><P>Atypical antipsychotic augmentation was demonstrated to be efficacious in treatment-resistant depression (TRD) in previous meta-analyses. We investigate whether there are differences in the effect size of atypical antipsychotic augmentation in major depressive disorder according to the degree of treatment resistance.</P><P><B>Methods:</B></P><P>A comprehensive search of four databases identified 11 randomized controlled trials. The 11 trials, which included 3 341 participants, were pooled using a random-effects meta-analysis.</P><P><B>Results:</B></P><P>Atypical antipsychotic augmentation of antidepressant therapy showed superior efficacy compared to antidepressant monotherapy in TRD in terms of both response and remission rates (response, risk ratio [RR] = 1.38, 95% confidence interval [CI] = 1.25 to 1.53; remission, RR = 1.62, 95% CI = 1.42 to 1.85). In addition, regarding response rates in the TRD trials, atypical antipsychotic augmentation exhibited significantly different effect sizes according to the degree of treatment resistance (TRD 1: RR = 1.24; TRD 2: RR = 1.37; TRD 2–4: RR = 1.58). In non-TRD trials, atypical antipsychotic augmentation failed to show superior efficacy over antidepressant monotherapy in terms of remission rates (RR = 0.89; 95% CI = 0.69 to 1.14). Atypical antipsychotic augmentation of antidepressant therapy exhibits greater effect size in patients with a higher degree of treatment resistance.</P><P><B>Conclusions:</B></P><P>This finding strengthens the rationale for considering atypical antipsychotic augmentation among depressed patients with multiple previous treatment failures in clinical practice. The efficacy of atypical antipsychotic augmentation for non-TRD seems to be different from that for TRD and, thus, further studies of non-TRD populations are needed.</P>