• Title/Summary/Keyword: Cooperativity

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A Study on the Correctional Policy through Comparison of Juvenile Delinquents and Normal Adolescents: Focusing on Self-esteem and Sociality (비행청소년과 일반청소년의 비교를 통한 교정정책연구 -자아존중감과 사회성을 중심으로-)

  • Lee, Duk-Nam
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.1
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    • pp.169-179
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    • 2014
  • This study conducted a comparison analysis of the differences by scope between juvenile delinquents, under sentence of juvenile protective disposition, and normal middle high school boys' self-esteem and sociality; it aims to search for the correctional policy to prevent juvenile delinquency. I conducted a survey, as a sampling target, of students (84) at Daedeok Juvenile Reformatory, located in Daejeon-si, Korea, and the normal middle high school boys (230). The results of analysis showed that in the analysis of self-esteem difference, juvenile delinquents were found high in the global self-esteem and school-academic self-esteem, but the normal adolescents were found high only in the scope of family-parents self-esteem. In leadership, a subordinate scope of sociality, juvenile delinquents showed the high result, and in independence and cooperativity, normal adolescents were found high. In conclusion, as the distinction between self-esteem and sociality is different by scope, depending on the individual's characteristic and environment, it suggests that the correctional policy through the customized plan is effective at preventing delinquency.

Unfolding of Ervatamin C in the Presence of Organic Solvents: Sequential Transitions of the Protein in the O-state

  • Sundd, Monica;Kundu, Suman;Dubey, Vikash Kumar;Jagannadham, Medicherla V.
    • BMB Reports
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    • v.37 no.5
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    • pp.586-596
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    • 2004
  • The folding of ervatamin C was investigated in the presence of various fluorinated and non-fluorinated organic solvents. The differences in the unfolding of the protein in the presence of various organic solvents and the stabilities of O-states were interpreted. At pH 2.0, non-fluorinated alkyl alcohols induced a switch from the native $\alpha$-helix to a $\beta$-sheet, contrary to the $\beta$-sheet to $\alpha$-helix conversion observed for many proteins. The magnitude of ellipticity at 215 nm, used as a measure of $\beta$-content, was found to be dependent on the concentration of the alcohol. Under similar conditions of pH, fluorinated alcohol enhanced the intrinsic a-helicity of the protein molecule, whereas the addition of acetonitrile reduced the helical content. Ervatamin C exhibited high stability towards GuHCl induced unfolding in different O-states. Whereas the thermal unfolding of O-states was non-cooperative, contrary to the cooperativity seen in the absence of the organic solvents under similar conditions. Moreover, the differential scanning calorimetry endotherms of the protein acquired at pH 2.0 were deconvoluted into two distinct peaks, suggesting two cooperative transitions. With increase in pH, the shape of the thermogram changed markedly to exhibit a major and a minor transition. The appearance of two distinct peaks in the DSC together with the non-cooperative thermal transition of the protein in O-states indicates that the molecular structure of ervatamin C consists of two domains with different stabilities.

Cooperative Activity of Subunits of Human Ferritin Heteropolymers in Escherichia coli

  • Lee, Jung;Seo, Hyang-Yun;Jeon, Eun-Soon;Park, Ok-Soon;Lee, Kang-Min;Park, Chung-Ung;Kim, Kyung-Suk
    • BMB Reports
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    • v.34 no.4
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    • pp.365-370
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    • 2001
  • We constructed a comparative expression system in order to produce recombinant human ferritin homo- and heteropolymers in Escherichia coli. Human ferritin H-(hfH) and L-chain (hfL) genes were expressed without amino acid changes under the control of a tac promoter. Ferritin heteropolymers of varying subunit composition were also produced by combining two different expression systems, a bicistronic expression system and a coplasmid expression system. As a result, recombinant H-chain ferritin and ferritin heteropolymers were catalytically active in forming iron core in vivo. In particular, the ferritin heteropolymer that is composed of 7% H-subunit and 93% L-subunit was capable of forming an iron core of the protein, while the L-chain ferritin homopolymer was inactive in vivo. This result indicates that the two H-subunits (i.e., 7% H-subunit content) are important to keep ferritin active in the cells. In addition, human ferritins were identified as the major iron binding proteins in the transformed cells. Also, the amount of iron bound to the recombinant ferritins was proportional to the H-subunit content in ferritin heteropolymers in vivo.

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Alcohol and Temperature Induced Conformational Transitions in Ervatamin B: Sequential Unfolding of Domains

  • Kundu, Suman;Sundd, Monica;Jagannadham, Medicherla V.
    • BMB Reports
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    • v.35 no.2
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    • pp.155-164
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    • 2002
  • The structural aspects of ervatamin B have been studied in different types of alcohol. This alcohol did not affect the structure or activity of ervatamin B under neutral conditions. At a low pH (3.0), different kinds of alcohol have different effects. Interestingly, at a certain concentration of non-fluorinated, aliphatic, monohydric alcohol, a conformational switch from the predominantly $\alpha$-helical to $\beta$-sheeted state is observed with a complete loss of tertiary structure and proteolytic activity. This is contrary to the observation that alcohol induces mostly the $\alpha$helical structure in proteins. The O-state of ervatamin B in 50% methanol at pH 3.0 has enhanced the stability towards GuHCl denaturation and shows a biphasic transition. This suggests the presence of two structural parts with different stabilities that unfold in steps. The thermal unfolding of ervatamin B in the O-state is also biphasic, which confirms the presence of two domains in the enzyme structure that unfold sequentially. The differential stabilization of the structural parts may also be a reflection of the differential stabilization of local conformations in methanol. Thermal unfolding of ervatamin B in the absence of alcohol is cooperative, both at neutral and low pH, and can be fitted to a two state model. However, at pH 2.0 the calorimetric profiles show two peaks, which indicates the presence of two structural domains in the enzyme with different thermal stabilities that are denatured more or less independently. With an increase in pH to 3.0 and 4.0, the shape of the DSC profiles change, and the two peaks converge to a predominant single peak. However, the ratio of van't Hoff enthalpy to calorimetric enthalpy is approximated to 2.0, indicating non-cooperativity in thermal unfolding.

Interaction of Nonsedating Antihistamines with Cerebral Muscarinic Receptors (비수기성 항 Histamine제와 대뇌 Muscarine 수용체와의 상호작용)

  • 김영열;이정수;박인숙
    • YAKHAK HOEJI
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    • v.43 no.5
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    • pp.642-651
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    • 1999
  • Nonsedating antihistamines do net cause sedation in therapeutic doses because these drugs hardly cross the blood-brain barrier. Since most of the peripheral side dffects of conventional antihistamines are related to their muscarinic receptor blocking action, the present study was performed to investigate whether nonsedating antihistamines interact with the muscarinic receptors and discriminate the muscarinic receptor subtypes in the rat cerebral microsomal fraction which containes both $M_1,{\;}M_2,{\;}M_3{\;}and{\;}M_4$ receptors. Five nonsedating antihistamines at high concentrations inhibited [$^3H$]QNB binding to the muscarinic receptor in a dose-dependent manner. The inhibition curves of these drugs except loratadine which showed positive cooperativity (nH=1.55) were steep (nH=1), indicating interaction with a single homogenous population of the binding sites. Astemizole, clemizole and mequitazine increased the $K_D$ value for [$^3H$]QNB without affecting the binding site concentrations, and this increase in the $K_D$ value resulted from the ability of these drugs to slow [$^3H$]QNB-receptor association. The Ki values of astemizole, clemizole and mequitazine for the inhibition for the inhibition of [$^3H$]QNB binding to muscarinic receptor were 0.58, 5.99 and $0.007{\;}{\mu}M$, respectively. However, loratadine and terfenadine inhibited noncompetitively [$^3H$]QNB binding with the normalized $IC_50$ value of about $2{\;}{\mu}M$. These results demonstrate that; 1) astemizole, clemizole and mequitazine interact directly with the muscarinic receptor at high concentrations; 2) muscarinic receptor blocking potency of these drugs varies widely among drugs; 3) these drugs do not discriminate between muscarinic receptor subtypes.

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Metabolic Interactions of Cannabinoids with Steroid Hormones

  • Watanabe, Kazuhito
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2007.11a
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    • pp.57-64
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    • 2007
  • Metabolic interactions of the three major cannabinoids, ${\Delta}^9$-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) with steroid hormones were investigated. These cannabioids concentration-dependently inhibited $3{\beta}$-hydroxysteroid dehydrogenase and $17{\alpha}$-hydroxylase in rat adrenal and testis microsomes. CBD and CBN were the most potent inhibitors of $3{\beta}$-phydroxysteroid dehydrogenase and progesterone $17{\alpha}$-hydroxylase, respectively, in rat testis microsomes. Three cannabinoids highly attenuated hCG-stimulated testosterone production in rat testicular interstitial cells. These cannabinoids also decreased in levels of mRNA and protein of StAR in the rat testis cells. These results indicate that the cannabinoids could interact with steroid hormones, and exert their modulatory effects on endocrine and testicular functions. Metabolic interaction of a THC metabolite, $7{\beta}$-hydroxy-${\Delta}^8$-THC with steroids is also investigated. Monkey liver microsomes catalyzed the stereoselective oxidation of $7{\beta}$-hydroxy-${\Delta}^8$-THC to 7-oxo-${\Delta}^8$-THC, so-called microsomal alcohol oxygenase (MALCO). The reaction is catalyzed by CYP3A8 in the monkey liver microsomes, and required NADH as well as NADPH as an efficient cofactor, and its activity is stimulated by some steroids such as testosterone and progesterone. Kinetic analyses revealed that MALCO-catalyze reaction showed positive cooperativity. In order to explain the metabolic interaction between the cannabinoid metabolite and testosterone, we propose a novel kinetic model involving at least three binding sites for mechanism of the metabolic interactions.

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Characteristic of Aromatic Amino Acid Substitution at α96 of Hemoglobin

  • Choi, Jong-Whan;Lee, Jong-Hyuk;Lee, Kwang-Ho;Lee, Hyean-Woo;Sohn, Joon-Hyung;Yoon, Joon-Ho;Yeh, Byung-Il;Park, Seung-Kyu;Lee, Kyu-Jae;Kim, Hyun-Won
    • BMB Reports
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    • v.38 no.1
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    • pp.115-119
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    • 2005
  • Replacement of valine by tryptophan or tyrosine at position $\alpha$96 of the $\alpha$ chain ($\alpha$96Val), located in the ${\alpha}_1{\beta}_2$ subunit interface of hemoglobin leads to low oxygen affinity hemoglobin, and has been suggested to be due to the extra stability introduced by an aromatic amino acid at the $\alpha$96 position. The characteristic of aromatic amino acid substitution at the $\alpha$96 of hemoglobin has been further investigated by producing double mutant r Hb ($\alpha$42Tyr$\rightarrow$ Phe, $\alpha$96Val$\rightarrow$Trp). r Hb ($\alpha$42Tyr$\rightarrow$Phe) is known to exhibit almost no cooperativity in binding oxygen, and possesses high oxygen affinity due to the disruption of the hydrogen bond between $\alpha$42Tyr and $\beta$99Asp in the ${\alpha}_1{\beta}_2$ subunit interface of deoxy Hb A. The second mutation, $\alpha$96Val$\rightarrow$Trp, may compensate the functional defects of r Hb ($\alpha$42Tyr$\rightarrow$Phe), if the stability due to the introduction of trypophan at the $\alpha$96 position is strong enough to overcome the defect of r Hb ($\alpha$42Tyr$\rightarrow$Phe). Double mutant r Hb ($\alpha$42Tyr$\rightarrow$Phe, $\alpha$96Val$\rightarrow$Trp) exhibited almost no cooperativity in binding oxygen and possessed high oxygen affinity, similarly to that of r Hb ($\alpha$42Tyr$\rightarrow$Phe). $^1$H NMR spectroscopic data of r Hb ($\alpha$42Tyr$\rightarrow$Phe, $\alpha$96Val$\rightarrow$Trp) also showed a very unstable deoxy-quaternary structure. The present investigation has demonstrated that the presence of the crucible hydrogen bond between $\alpha$42Tyr and $\beta$99Asp is essential for the novel oxygen binding properties of deoxy Hb ($\alpha$96Val$\rightarrow$Trp).

Music Intervention for Psychological and Emotional Support of Korean Women: Research Analysis Focusing on a Feminist Perspective (국내 여성 대상 심리정서 지원을 위한 음악중재 연구 분석: 여성주의 관점을 중심으로)

  • Lee, Seong-Kyung;Kim, Aimee Jeehae
    • Journal of Music and Human Behavior
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    • v.15 no.1
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    • pp.69-94
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    • 2018
  • This study was conducted to analyze music therapy studies supporting the psychological and emotional needs of Korean women according to a feminist perspective in music therapy. A total of 34 studies were analyzed by general characteristics, characteristics of the intervention, and characteristics of a feminist perspective. Results showed that the research focus was initially on subjects who suffered from mental illness and that more recently the focus has shifted to include more diverse subjects, such as career women, women who migrate for marriage, and women who study abroad, and to reflect contemporary social issues. In terms of a feminist perspective, the studies were analyzed according to the following themes as the characteristics of a feminist perspective: empowerment, social and political perspectives, cooperativity, egalitarianism, and diversity. Results showed that social and political viewpoints were reflected in the selection of subjects and that empowerment was reflected mostly in the contents of interventions. This study highlights the need to incorporate a feminist perspective in more diversified music therapy practices to bring social changes as well as individual changes for women.

Reaction Mechanism of Purine Nucleoside Phosphorylase and Effects of Reactive Agents for SH Group on the Enzyme in Saccharomyces cerevisiae (Saccharomyces cerevisiae에서 얻은 Purine Nucleoside Phosphorylase의 반응기작과 효소에 대한 Sulfhydryl Reagent의 영향)

  • Choi, Hye-Seon
    • Korean Journal of Microbiology
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    • v.32 no.3
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    • pp.222-231
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    • 1994
  • Kinetic analysis was done to elucidate the reaction mechanism of purine nucleoside phosphorylase (PNP) in Saccharomyces cerevisiae. The binary complexes of PNP${\cdot}$phosphate and PNP${\cdot}$ribose 1-phosphate were involved in the reaction mechanism. The initial velocity and product inhibition studies demonstrated were consistent with the predominant mechanism of the reaction being an ordered bi, bi reaction. The phosphate bound to the enzyme first, followed by nucleoside and base were the first product to leave, followed by ribose 1-phosphate. The kinetically suggested mechanism of PNP in S. cerevisiae was in agreement with the results of protection studies against the inactivation of the enzyme by sulfhydryl reagents, p-chloromercuribenzoate (PCMB) and 5,5'-dithiobisnitrobenzoate (DTNB). PNP was protected by ribose 1-phosphate and phosphate, but not by nucleoside or base, supporting the reaction order of ordered bi, bi mechanism. PCMB or DTNB-inactivated PNP was totally reactivated by dithiothreitol (DTT) and the activity was returned to the level of 77% by 2-mercaptoethanol, indicating that inactivation was reversible. The kinetic behavior of the PCMB-inactivated enzyme had been changed with higher $K_m$ value of inosine and lower $V_m$, and was restored by DTT. Inactivation of enzyme by DTNB showed similar pattern of K sub(m) value with that by PCMB, but had not changed the $V_m$ value, significantly. Negative cooperativity was not found with PCMB or DTNB treated PNP at high concentration of phosphate.

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NMR Studies on the Structure of Human Annexin I

  • Han, Hee-Yong;Bang, Keun-Su;Na, Doe-Sun;Lee, Bong-Jin
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.182-182
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    • 1996
  • Annexin I is a member of the annexin family of calcium dependent phospholipid binding proteins and has anti-inflammatory activity by inhibiting phospholipase A$_2$ (PLA$_2$). Recent X-ray crystallographic study of annexin I identified six Ca$\^$2+/ binding bites, which was different types (type II, III) from the well-known EF-hand motif (type I). In this work, the structure of annexin I was studied at atomic level by using $^1$H, $\^$15/N and $\^$l3/C NMR(nuclear magnetic resonance) spectroscopy, and the effect of Ca$\^$2+/ binding on the structure of annexin I was studied, and compared with that of Mg$\^$2+/ binding, When Ca$\^$2+/ was added to annexin I, NMR peak change was occured in high- and low-field regions of $^1$H-NMR spectra. NMR peak change by Ca$\^$2+/ binding was different from that by Mg$\^$2+/ binding. Because annexin I is a larger protein with 35 kDa molecular weight, site-specific (amide-$\^$15/N, carbonyl-$\^$l3/C) labeling technique was also used. We were able to detect methionine, tyrosine and phenylalanine peaks respectively in $\^$13/C-NMR spectra, and each residue was able to be assigned by the method of doubly labeling annexin I with [$\^$13/C] carbonyl-amino acid and [$\^$15/N] amide-amino acid. In $\^$l3/C-NMR spectra of [$\^$13/C] carbonyl-Met labeled annexin I, we observed that methionine residues spatially located near Ca$\^$2+/ binding Sites Were Significantly effected by Ca$\^$2+/ binding. From UV spectroscopic data on the effect of Ca$\^$2+/ binding, we knew that Ca$\^$2+/ binding sites of annexin I have cooperativity in Ca$\^$2+/ binding. The interaction of annexin I with PLA$_2$ also could be detected by using heteronuclear NMR spctroscopy. Consequently, we expect that the anti-inflammatory action mechanism of annexin I may be a specific protein-protein interaction. The residues involved in the interaction with PLA$_2$ can be identified as active site by assigning NMR peaks effected by PLA$_2$ binding.

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