• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.12-16
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• 1999

Denaturation of actomyosin from the obliquely striated mantle muscle of squids (Todarodes pacificus) was studied by measuring the changes in $Ca^{2+}$-ATPase activity, relative viscosity, and solubility during frozen storage at three different temperature zones of maximum ice crystal formation $(-3^{\circ}C,\;-\;-5^{\circ}C)$, the eutectic point $(-11^{\circ}C)$, and $-20^{\circ}C$. The logarithms of $Ca^{2+}$-ATPase activity, relative viscosity and solubility of the actomyosin solutions (0.6 M KCl) and suspensions (0.05 M KCl) tended to decrease during frozen storage. The denaturation of squid actomyosin at the zone of maximum ice crystal formation significantly differed by only two degree of temperature difference between $-3^{\circ}C$ and $-5^{\circ}C$, and it (0.05 M KCl) at $-3^{\circ}C$ was less than those of other temperature. The denaturation at $-11^{\circ}C$ was more rapid than at $-5^{\circ}C$. The logarithms of $Ca^{2+}$ -ATPase activity, relative viscosity, and solubility were changed slower in the suspensions (0.05 M KCl) than the solutions (0.6 M KCl) at all experimental temperatures.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 1997년도 임시총회 및 제20차 추계학술발표회
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• pp.123-123
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• 1997

• 약학회지
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• 제28권3호
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• pp.129-138
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• 1984

Specific [$^{3}H$] ouabain binding and $Ca^{2+}$ -uptake were measured to elucidate the role of high affinity [$^{3}H$] ouabain binding site in rat cardiac myocytes which contain 65% of rod cells. High affinity [$^{3}$H] ouabain binding site, which is about 3% of total pump sites, with apparent dissociation constant ($K_{D}$) of $1.1{\times}10^{-7}M$ and maximum binding site concentration (Bmax) of 1.2 pmol/mg protein ($1.754{\times}10^{5}cells$) were identified. At the concentration of $10^{-7}M$ to $10^{-4}M$, ouabain produced concentration dependent increase in $Ca^{2+}$-uptake of myocytes. The effect of ouabain on $Ca^{2+}$-uptake was not effected by membrane depolarization (elevated K+ in incubation medium) or verapamil. These results suggest that in rat ventricular myocytes the ouabain receptor complex to high affinity site may increase Na+ - $Ca^{2+}$ exchange across the sarcolemmal membrane by inhibition of Na+, K+ - ATPase.

• The Korean Journal of Physiology and Pharmacology
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• 제16권1호
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• pp.31-36
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• 2012

The receptor activator of NF-${\kappa}B$ ligand (RANKL) signal is an activator of tumor necrosis factor receptor-associated factor 6 (TRAF6), which leads to the activation of NF-${\kappa}B$ and other signal transduction pathways essential for osteoclastogenesis, such as $Ca^{2+}$ signaling. However, the intracellular levels of inositol 1,4,5-trisphosphate ($IP_3$) and $IP_3$-mediated cellular function of RANKL during osteoclastogenesis are not known. In the present study, we determined the levels of $IP_3$ and evaluated $IP_3$-mediated osteoclast differentiation and osteoclast activity by RANKL treatment of mouse leukemic macrophage cells (RAW 264.7) and mouse bone marrow-derived monocyte/macrophage precursor cells (BMMs). During osteoclastogenesis, the expression levels of $Ca^{2+}$ signaling proteins such as $IP_3$ receptors ($IP_3Rs$), plasma membrane $Ca^{2+}$ ATPase, and sarco/endoplasmic reticulum $Ca^{2+}$ ATPase type2 did not change by RANKL treatment for up to 6 days in both cell types. At 24 h after RANKL treatment, a higher steady-state level of $IP_3$ was observed in RAW264.7 cells transfected with green fluorescent protein (GFP)-tagged pleckstrin homology (PH) domains of phospholipase C (PLC) ${\delta}$, a probe specifically detecting intracellular $IP_3$ levels. In BMMs, the inhibition of PLC with U73122 [a specific inhibitor of phospholipase C (PLC)[ and of $IP_3Rs$ with 2-aminoethoxydiphenyl borate (2APB; a non-specific inhibitor of $IP_3Rs$) inhibited the generation of RANKL-induced multinucleated cells and decreased the bone-resorption rate in dentin slice, respectively. These results suggest that intracellular $IP_3$ levels and the $IP_3$-mediated signaling pathway play an important role in RANKL-induced osteoclastogenesis.

• 한국식품영양학회지
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• 제10권4호
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• pp.468-474
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• 1997

쇠고기의 사태, 갈비 및 등심부위를 8$^{\circ}C$에 저장하면서 육질의 변화를 검토하기 위해 전단력가, 근원섬유의 소편화, actomyosin의 추출성 및 ATPase 활성을 측정하였다. 사태 및 등심부위의 전단력가는 저장 6일째 현저하게 낮아졌고, 갈비부위는 저장기간 동안 현저한 차이가 없었다. 저장초기 부위별 전단력가는 갈비, 등심 및 사태부위의 순으로 현저한 차이가 있었으나 저장기간이 경과하면서 갈비 및 등심부위는 비슷하였다. 근원 섬유 소편화도의 경우 사태부위는 저장 6일째 현저한 증가를 보였지만 갈비와 등심부위는 저장기간동안 계속 증가하였다. 근원섬유의 소편화율도 소편화도와 비슷한 양상이었으며, 갈비와 등심부위는 사태부위와 다른 변화를 보였다. Actomyosin의 추출성은 저장초기 갈비, 등심 및 사태부위의 순으로 높게 나타났으며 3일째 모든 부위가 증가하다가 등심부위는 저장 6일째 감소하였다. Acomyosin의 Mg2+-ATPase 활성의 경우, 사태부위는 저장 3일째 증가하다가 6일째 저장 0일의 수준으로 회복되었고, 갈비 및 등심부위는 비슷한 변화를 나타내었지만 0일째는 등심부위가 갈비부위보다 높게 나타났다. 그리고 사태부위의 Ca2+-ATPase 활성도 저장 3일째 증가하다가 6일째 감소하였으며, 갈비부위는 저장 중 변화가 없었고, 등심부위는 저장기간 동안 완만하게 감소하였다.

• 대한의생명과학회지
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• 제3권1호
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• pp.1-9
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• 1997

대부분의 포유동물들에서 수정전에 정자의 첨체반응이 일어난다고 알려져 있으며 첨체반응에서 $Ca^{2+}$ 이 중요한 역할을 한다고 알려져 있다. 단백질 또한 정자의 생리적 역할에 중요한 요소로 작용한다고 보고되고 있다. 본 실험에서는 동면동물의 부정소에서 정자성숙과정을 비교 관찰하고 성숙 과정에 있어 $Ca^{2+}$ 농도와의 연관성을 규명하고 정자성숙 전, 후에 정자성숙에 영향을 미치는 $Mg^{2+}$-ATPase, lactate dehydrogenase의 작용을 비교, 분석하였다. 그 결과 다음과 같은 결과를 얻었다. 대표적 동면동물인 박쥐의 경우 활동기에 다른 동면동물인 햄스터, 항온동물인 생쥐와 마찬가지로 부정소미에서 정자성숙과정을 거쳤으며 교미시 대부분의 정자는 부정소미에서 더욱 활발한 운동성을 보였으며 부정소미 말에서 수정능획득 과정을 거치는 것으로 관찰되었다. 그러나 동면동물의 환경 조건 특히 온도의 변화가 부정소에서의 정자성숙과정에 영향을 주는지에 대해서는 더 자세한 연구가 필요하다고 사료된다.

• Journal of Plant Biology
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• 제37권3호
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• pp.271-276
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• 1994

The possibility that 1-aminocyclopropane-1-carboxylic acid (ACC)-uptake may be dependent on the H+-gradient established across the plsma membrane was tested in protoplasts isolated from 2.5 day old mungbean hypocotyls. The ACC-induced ethylene production was inhibited when the H+-gradient was collapsed by the treatment with carbonycyamide-p-trifluro-methoxy-phenylhydrazone (FCCP). Moreover, the treatment with o-vanadate, a specific inhibitor of plasma membrane H+-ATPase, caused the inhibition of ethylene production. The ACC-induced ethylene production was inhibited by the treatemnt with verapamil (Ca2+-channel blocker), or ethylene glycol-bis($\beta$-aminoethyl ether) N, N, N', N'-tetraacetic acid (EGTA) (Ca2+-chelator). In contrast, the ehtylene production was stimulated by the application of A23187 (Ca2+ ionophore). The inhibitory effect of EGTA in the ethylene producton was magnified in the presence of A23187. From these results, we suggest that the external Ca2+ influx to the cytosol resulted in the stimulatin of ACC oxidase activity after ACC-uptake resulting from a H+-gradient across the plasma membrane.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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• pp.56-56
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• 2002

Muscle contraction and relaxation are regulated by the sarcoplasmic reticulum (SR)-mediated $Ca^{2＋}$ release and $Ca^{2＋}$ uptake. The SR functions are closely related with the proteins residing in the SR such as ryanodine receptor, $Ca^{2＋}$-ATpase, calsequestrin, triadin and junctin. In an effort to further identify important functional SR proteins, experiments of sucrose-density gradient of SR fractionation, concanavalin A treatment, 2D gel electrophoresis, $^{45}$ Ca$^{2+}$ overlay, Strains-all staining, and peptide finger printing (PFP) were carried out.(omitted)d)

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.383-388
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• 2011

Regulators of G-protein signaling (RGS) proteins are regulators of $Ca^{2+}$ signaling that accelerate the GTPase activity of the G-protein ${\alpha}$ -subunit. RGS1, RGS2, RGS4, and RGS16 are expressed in the pancreas, and RGS2 regulates G-protein coupled receptor (GPCR)-induced $Ca^{2+}$ oscillations. However, the role of RGS4 in $Ca^{2+}$ signaling in pancreatic acinar cells is unknown. In this study, we investigated the mechanism of GPCR-induced $Ca^{2+}$ signaling in pancreatic acinar cells derived from $RGS4^{-/-}$ mice. $RGS4^{-/-}$ acinar cells showed an enhanced stimulus intensity response to a muscarinic receptor agonist in pancreatic acinar cells. Moreover, deletion of RGS4 increased the frequency of $Ca^{2+}$ oscillations. $RGS4^{-/-}$ cells also showed increased expression of sarco/endoplasmic reticulum $Ca^{2+}$ ATPase type 2. However, there were no significant alterations, such as $Ca^{2+}$ signaling in treated high dose of agonist and its related amylase secretion activity, in acinar cells from $RGS4^{-/-}$ mice. These results indicate that RGS4 protein regulates $Ca^{2+}$ signaling in mouse pancreatic acinar cells.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2002년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.118-119
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• 2002

근육이 수축하면 근원섬유의 sarcomere (근절)의 길이가 경직의 진행과 함께 짧아지는 것을 볼 수 있다. 즉, thick filament (myosin filament)와 thin filament (actin filament) 사이에서로 미끌어져 들어가는 현상이 일어나게 되는 것이다. 골격근은 보통 때는 이완상태에 있으나 필요할 때 신경자극에 의해서 수축을 하게 된다. 이러한 수축↔이완의 전환은 세포내의 $Ca^{2+}$ 농도의 조절을 통해서 제어되며, 이완시의 세포질 내의 $Ca^{2+}$ 농도는 정도의 낮은 상태로 유지된다. (중략)