• 제목/요약/키워드: biophysical model

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NMR Study on the Internal Dynamics of Ketosteroid Isomerase

  • Lee, Hee-Cheon
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.26-26
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    • 2003
  • The backbone dynamics of ketosteroid isomerase, a homodimeric enzyme with 125 amino acid residues per subunit, has been studied in the presence/absence of a steroid ligand and 5% trifluoroethanol (TFE) by $^{15}$ M relaxation measurements. The relaxation data were analyzed using the model-free formalism to extract the model-free parameters (S$^2$, $\tau$$_{e}$, and R$_{ex}$ ). The results show that a large number of the residues, particularly those involved in the dimer interaction, exhibit reduced order parameters (S$^2$) in the steroid-bound enzyme, indicating the increased high-frequency (pico- to nanosecond) motions in the interface region upon ligand binding. The results also show that that the presence of 5 % TFE in free enzyme causes little change or slight increase in the order parameters for a number of residues in the dimer interface region. However, the majority of the residues in free enzyme exhibit reduced order parameters in the presence of 5 % TFE, indicating that the increase in entropy is partially responsible for the increased stability of KSI by 5% TFE.E.E.

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Morphological and functional changes of dissociated single pancreatic acinar cells: testing the single cell as a model for exocytosis and calcium signaling

  • Lee, Misun;Uhm, Dae-Yong;Park, Myoung-Kyu
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.56-56
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    • 2003
  • Isolated single pancreatic acinar cells have long been used as a good model for studying many kinds of signaling processes due to their good structural and functional polarities without a significant validation. In this study, we have examined morphological and functional changes of the dissociated single pancreatic acinar cells by imaging cytosolic Ca$\^$2+/ concentration, exocytosis of granules, and by observing their shapes with confocal microscopy.

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Preferred Conformations of Cyclic Ac-Cys-Pro-Xaa-Cys-NHMe Peptides: a Model for Chain Reversal and Active Site of Disulfide Oxidoreductase

  • Park, Hae-Sook;Kim, Choonmi;Kang, Young-Kee
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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    • pp.35-35
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    • 2001
  • The conformational study on cyclic Ac-Cys-Pro-Xaa-Cys-NHMe (Ac-CPXC-NHMe; X = Ala, Val, Leu, Aib, Gly, His, Phe, Tyr, Asn, and Ser) peptides has been carried out using the ECEPP/3 force field and the hydration shell model in the unhydrated and hydrated states. This work has been undertaken to investigate structural implications of the CPXC sequence as the chain reversal for the initiation of protein folding and as the motif for active site of disulfide oxidoreductases.(omitted)

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경락 전위를 이용한 경락의 생체물리학적 연구 (Study on the Electric Potentials at Biophysical Meridian System)

  • 최환수;남봉현
    • Korean Journal of Acupuncture
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    • 제19권2호
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    • pp.1-12
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    • 2002
  • Objectives : Assuming That the Characteristic of Meridian System Has Been Similar to This of Electric Potentials in Human Body and That Measurements of Electric Potential at Well and Sea Points in Branches of the Twelve Meridians Will Be Representative of Measurements of the Twelve Meridians, to Measure the Electric Potentials in Healthy Volunteers(HG), Patients Diagnosed As a Cerebral Infarction(CG), a Arrhythmia(AG), a Other Intervertebral Disc Disorder(IG), and a Joint Disorder(JG), and Then to Find Out the Characteristic of Biophysical Meridian System, Finally to Compare with the Results of the Electric Potential in Those Groups. Methods : We Selected Who HG Were Diagnosed by a Blood Test, Urine Examination and Differentiation of Syndromes by Five Viscera among Volunteers, CG by CT and Wind-Syndrome Caused by Hyperactivity of the Liver-Yang, AG by EKG, CT, and Deficiency or the Heart Blood, IG by X-ray or CT and Pain in Waist, and JG by X-ray and Knee Pain. Their Electric Potential of Well and Sea Points in the Meridians Were Measured by hysiograph. Results and Conclusions : Measurements Were Analyzed by Factor Analysis, Analysis of Variance, and Logistic Regression Model, We Obtained That Most of the Results, In Conclusion, Hold Good for the Classical Meridian Doctrine.

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Simulation of ATP Metabolism in Cardiac Excitation - Contraction Coupling

  • Matsuoka, Satoshi;Sarai, Nobuaki;Jo, Hikari;Noma, Akinori
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.19-19
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    • 2003
  • We have developed a cardiac cell model (Kyoto Model) for the sinoatrial node and ventricle, which is composed of a common set of kinetic equations of membrane ionic currents, Ca$\^$2+/dynamics of sarcoplasmic reticulum and contractile protein. To expand this model by including metabolic pathways, the intracellular ATP metabolism, which is pivotal in cardiac excitation - contraction coupling, was incorporated. ATP consumption by the sarcolemmal Na$\^$+/ pump and the Ca pump in the sarcoplasmic reticulum were calculated with stoichiometry of 3Na:2K:1ATP and 2Ca:1ATP, respectively. ATP consumption by contraction was estimated according to experimental data. Dependence of contraction on ATP and inorganic phosphate was modeled, based on data of skinned cardiac fiber. in production by mitochondrial oxidative phosphorylation was modified from Korzeniewski '||'&'||' Zoladz (2001), and creatine kinase and adenylate kinase reactions were incorporated. ATP dependence of ATP-sensitive K channel and L type Ca channel were also included.

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Altered Sarcoplasmic Reticulum $Ca^{2+}$ Uptake of H9c2 Cells Cultured in High Glucose Medium

  • Lee, Eun-Hee;Seo, Young-Joo;Lee, Jun-Whee;Jang, Joong-Sik;Kim, Young-Hoon;Kim, Hae-Won
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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    • pp.40-40
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    • 2002
  • Altered intracellular $Ca^{2+}$ homeostasis is presumably the primary mechanism of the diastolic impairment in diabetic cardiomyopathy. However, causal relations of numerous environmental changes observed in the diabetic heart have been left unresolved. In the present study, we sought to establish an in vitro model of diabetic cardiomyopathy using H9c2 cardiac myocyte cell line.(omitted)

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Ion Transports in Mouse Collecting Duct Cells (M-1)

  • Park, Mi-Young;Song, Jin-Mi;Jang, Phil-Geum;Lee, Ryang-Hwa;Jung, Jin-Sup
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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    • pp.50-50
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    • 1999
  • The mammalian cortical collecting duct (CCD) plays a major role in regulating renal NaCl absorption, which is important in controlling total body Na and Cl homeostasis. The M-1 cell line, derived from the mouse cortical collecting duct, is being used as a mammalian model of the CCD to study electrolytes transport.(omitted)

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From Folding to Sweet Taste: NMR, Circular Dichroism and Fluorescence Studies on Sweet Protein, Monellin

  • Lee, Weontae;Sung, Yoon-hui;Heedouk Hong;Chaejoon Cheong;Cho, Joong-Myung
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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    • pp.18-18
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    • 1999
  • A sweet protein monellin was originally isolated from the berries of the West African plant Dioscoreophyllum cumminsii. The studies for molecular interaction of different sweeteners with receptor as well as receptor binding model have been proposed previously. The high-resolution solution structure of single-chain monellin (SCM) has been determined to investigate structural origin of sweet taste by NMR spectroscopy and simulated annealing calculations.(omitted)

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An Input-correlated Neuron Model and Its Learning Characteristics

  • Yamakawa, Takeshi;Aonishi, Toru;Uchino, Eiji;Miki, Tsutomu
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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    • pp.1013-1016
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    • 1993
  • This paper describes a new type of neuron model, the inputs of which are interfered with one another. It has a high mapping ability with only single unit. The learning speed is considerably improved compared with the conventional linear type neural networks. The proposed neuron model was successfully applied to the prediction problem of chaotic time series signal.

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LET 증가에 따른 회복 생존 모델의 파라미터 값 비교 (Comparison of Parameter Using the Repair Survival Model Irradiated High-LET)

  • 최은애
    • 한국방사선학회논문지
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    • 제11권4호
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    • pp.177-181
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    • 2017
  • 방사선 생물학적 효과(Radio biological effectiveness, RBE)를 선량에 대부분 의존하는 X선과 달리 탄소빔의 경우 LET의 변화량은 반드시 고려되어야할 사항이다. 이는 X선 과는 극히 대조적인 선량 분포도를 갖고 있기 때문이며 LET의 변화량이 중요한 이유가 된다. 따라서 기존의 LQ 모델이나 회복생존모델의 경우 이러한 점이 감안되지 않아 탄소빔의 분할 조사 시 문제점을 보이며 오류를 보이고 있다. 본 연구에서는 약 $75keV/{\mu}m$의 고LET 탄소빔 분할 조사 시 Potentially Lethal Damage Repair (PLDR)의 발생양을 확인하고 약 $13keV/{\mu}m$ 저LET 조사와 비교하여 현저히 감소하였음을 확인하였다. PLDR의 감소에 따라 생존율 또한 감소하였다. 따라서 탄소빔의 생물리학적 모델 개발에 LET의 변화량은 반드시 고려되어져야 할 것으로 보인다.