• 한국수정란이식학회지
• /
• 제24권4호
• /
• pp.237-247
• /
• 2009

Melatonin (N-acetyl-5-methoxytryptamine) is the major neurohormone secreted during the night by the vertebrate pineal gland. The circadian pattern of pineal melatonin secretion is related to the biological clock within the suprachiasmatic nucleus (SCN) of the hypothalamus in mammals. The SCN coordinates the body's rhythms to the environmental light-dark cycle in response to light perceived by the retina, which acts mainly on retinal ganglion cells that contain the photopigment melanopsin. Calbindin-D9k (CaBP-9k) is a member of the S100 family of intracellular calcium- binding proteins, and in this review, we discuss the involvement of melatonin and CaBP-9k with respect to calcium homeostasis and apoptotic cell death. In future studies, we hope to provide important information on the roles played by CaBP-9k in cell signal transduction, cell proliferation, and $Ca^{2+}$ homeostasis in vivo and in vitro.

• Journal of Microbiology and Biotechnology
• /
• 제27권12호
• /
• pp.2241-2244
• /
• 2017

The structure of concanavalin A (ConA) has been studied intensively owing to its specific interactions with carbohydrates and its heterometal ($Ca^{2+}$ and $Mn^{2+}$) coordination. Most structures from X-ray crystallography have shown ConA as a dimer or tetramer, because the complex formation requires specific crystallization conditions. Here, we reported the monomeric structure of ConA with a resolution of $1.6{\AA}$, which revealed that metal coordination could trigger sugar-binding ability. The calcium coordination residue, Asn14, changed the orientation of carbohydrate-binding residues and biophysical details, including structural information, providing valuable clues for the development and application of detection kits using ConA.

• 한국식품위생안전성학회:학술대회논문집
• /
• 한국식품위생안전성학회 2002년도 춘계학술발표대회 및 심포지움
• /
• pp.215-215
• /
• 2002

Catalytic subunit of pyruvate dehydrogenase phosphatase (PDPc) has been suggested to have three major funational domains such as dihydrplipoamide adetyltransferase(E2)-binding domain, regulatory subunit of PDP(PDP)r-binding domain, and calcium-binding domain. In order to identify functional domains, recombinant catalytic subunit of pyruvate dehydrogenase phosphatase(rPDPc) was expressed in E. coli JM101 and purified to near homogeneity using the unique property of PDPc: PDPc binds to the inner lipoyl domain (L2) of E2 of ppyruvate dehydrogenase complex (PDC) in the presence of Ca+2, not under EGTA. PDPc was limited-proteolysed by typsin, chymotypsin, Arg-C, and elastase at pH 7.0 and 30C and N-terminal analysis of the fragments was done. Chymotrypsin, trypsin, and elastase made two major fragments: N-terminal large fragment, approx. 50kD and C-terminal small fragment, approx.10 kDa. Arg-C made three major fragments: N-terminal fragment, approx. 35kD, and central fragment, approx. 15 kD, and C-terminal fragment, approx. 10 kD. This study strongly suggest that PDPc consists of three major functional domains. However, further study should be necessary to identify the functional role.

• 펄프종이기술
• /
• 제41권2호
• /
• pp.26-33
• /
• 2009

A new testing method to evaluate the deposition potential of white pitch was developed. The new method involves depositing the potential white pitch particles on the air bubble covered plastic film in the pitch deposit tester (PDT) developed by KRICT and analysing the deposited area of white pitch using an image analyzer. In addition, the effect of two important factors (pH and calcium hardness) on white pitch deposition potential was elucidated. When pH of the coated broke stock was increased from neutral to alkali or the calcium hardness of the stock was decreased, the pitch deposit area was decreased, implying that these two factors have to be controlled during the evaluation of pitch deposition potential. It was found that hydrophobicity of the surface of latex binding films repulped is a key factor influencing white pitch deposition.

• Biomolecules & Therapeutics
• /
• 제18권2호
• /
• pp.152-158
• /
• 2010

Melanin concentrating hormone is a neuropeptide highly expressed in the brain that regulates several physiological functions mediated by receptors in the G-protein coupled receptor family, especially plays an important role in the complex regulation of energy balance and body weight mediated by the melanin concentrating hormone receptor subtype 1 (MCH1). Compelling pharmacological evidence implicating MCH1 signaling in the regulation of food intake and energy expenditure has generated a great deal of interest by pharmaceutical companies as MCH1 antagonists may have potential therapeutic benefit in the treatment of obesity and metabolic syndrome. Although fluorescence-based calcium mobilization assay platform has been one of the most widely accepted tools for receptor research and drug discovery, fluorescence interference and shallow assay window limit their application in high throughput screening and have led to a growing interest in alternative, luminescence-based technologies. Herein, a luminescence-based functional assay system for the MCH1 receptor was developed and validated with the mitochondrial targeted aequorin. Aequorin based functional assay system for MCH1 presented excellent Z' factor (0.8983) and high signal-to-noise ratio (141.9). The nonpeptide MCH1 receptor antagonist, SNAP 7941 and GSK 803430, exhibited $IC_{50}$ values of 0.62 ${\pm}$ 0.11 and 12.29 ${\pm}$ 2.31 nM with excellent correlation coefficient. These results suggest that the aequorin based assay system for MCH1 is a strong alternative to the traditional GPCR related tools such as radioligand binding experiments and fluorescence functional determinations for the compound screening and receptor research.

• BMB Reports
• /
• 제39권5호
• /
• pp.607-617
• /
• 2006

A novel calcium-dependent protein kinase gene (designated as IiCPK2) was cloned from tetraploid Isatis indigotica. The full-length cDNA of IiCPK2 was 2585 bp long with an open reading frame (ORF) of 1878 bp encoding a polypeptide of 625 amino acid residues. The predicted IiCPK2 polypeptide included three domains: a kinase domain, a junction domain (or autoinhibitory region), and a C-terminal calmodulin-like domain (or calcium-binding domain), which presented a typical structure of plant CDPKs. Further analysis of IiCPK2 genomic DNA revealed that it contained 7 exons, 6 introns and the length of most exons was highly conserved. Semi-quantitative RT-PCR revealed that the expression of IiCPK2 in root, stem and leaf were much higher in tetraploid sample than that in diploid progenitor. Further expression analysis revealed that gibberellin ($GA_3$), NaCl and cold treatments could up-regulate the IiCPK2 transcription. All our findings suggest that IiCPK2 might participate in the cold, high salinity and GA3 responsive pathways.

• BMB Reports
• /
• 제50권9호
• /
• pp.454-459
• /
• 2017

Tumor suppressor candidate 2 (Tusc2, also known as Fus1) regulates calcium signaling, and $Ca^{2+}$-dependent nuclear factor of activated T-cells (NFAT) and nuclear factor kappa B ($NF-{\kappa}B$) pathways, which play roles in osteoclast differentiation. However, the role of Tusc2 in osteoclasts remains unknown. Here, we report that Tusc2 positively regulates the differentiation of osteoclasts. Overexpression of Tusc2 in osteoclast precursor cells enhanced receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. In contrast, small interfering RNA-mediated knockdown of Tusc2 strongly inhibited osteoclast differentiation. In addition, Tusc2 induced the activation of RANKL-mediated $NF-{\kappa}B$ and calcium/calmodulin-dependent kinase IV (CaMKIV)/cAMP-response element (CRE)-binding protein CREB signaling cascades. Taken together, these results suggest that Tusc2 acts as a positive regulator of RANKL-mediated osteoclast differentiation.

• 전기화학회지
• /
• 제5권2호
• /
• pp.43-46
• /
• 2002

Commercial titanium rod was anodized in three types of electrolytes such as 0.06 mol/L $\beta-glycerophosphate+0.3mol/L$ calcium acetate, 0.06mol/L $\beta-glycerophosphate+0.3mol/L$ sodium acetate and 0.06 mol/L $\beta-glycerophosphate+5mol/L$ calcium phosphate. The titanium oxide layer $(TiO_2)$ was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and electron spectroscopy chemical analysis (ESCA). Numerous micropores were observed on the titanium oxide layer by SEM. The diameter of micropores increased with the increase of electrolytic voltage. The titanium oxide layer was composed of anatase structure. The phosphorous element was detected at 130 eV binding energy, but calcium was not found in the oxide layer because of lower contents. After anodizing the oxide layer was etched in the 30g/L NaOH solution at $80^{\circ}C$ for 1hr. The surroundings of micropores were much more smoothed and rounded than before alkaline etching.

• 통합자연과학논문집
• /
• 제17권1호
• /
• pp.31-41
• /
• 2024

Calcium ions play an important role in development and intracellular signaling. Dictyostelium discoideum has 14 genes encoding calcium -binding proteins (CBPs), but the function of most CBPs during development has not yet been studied. In this study, we investigated the specific functions of CBP7, one of 14 CBPs, in development using RNA interference cell lines of CBP7, cell lines overexpressing CBP7, cell lines with point mutations in the EF-hand domain, and cell lines expressing fragment proteins. was intended to reveal. CBP7 consists of 169 amino acids and contains 4EF-hand domains. The CBP7-overexpressing cells showed complete loss of developmental process. These cells remained in the single-cell growth stage under development -inducing conditions, while wild-type cells formed aggregations within 6-8h of development and eventually formed fruiting bodies. The experiments using point-mutated CBP7 protein showed that all EF-hand domains of CBP7 were important for CBP7 to function during developmental process. These results suggest that CBP7 plays an important role in developmental processes across all EF-hand domains.

• 공업화학
• /
• 제30권6호
• /
• pp.726-730
• /
• 2019

본 연구는 제올라이트를 이용한 칼슘이온 제거에 대한 것으로 시멘트 산업에서 발생하는 cement kiln dust를 이용한 CaCO₃ 제조 공정의 문제를 해결하기 위함이다. 칼슘이온을 제거하기 위하여 제올라이트를 개질하여 사용하였으며 결합 양이온 및 구조를 고려한 최적 제올라이트 선정, 칼슘이온 제거 성능 평가, 개질 용액의 종류 및 농도의 영향, K 공존 시 제거 선택도 평가에 대해 연구를 수행하였다. 5종의 제올라이트 중 13X 제올라이트의 칼슘 이온 제거 성능이 가장 우수함을 확인하였고 NaCl 대신 KCl을 개질 용액으로 사용하였을 때 칼슘이온 제거 성능이 증진되는 것을 확인할 수 있었다. 본 연구는 탄산화 공정의 문제 해결, 고농도의 KCl 회수 기술의 바탕이 될 것으로 판단된다.