• Parasites, Hosts and Diseases
• /
• v.43 no.3 s.135
• /
• pp.119-122
• /
• 2005

Calcareous corpuscles are a characteristic structure found in larval and adult stage cestddes, These corpuscles are known to contain several protein components and to possess protein-binding activity. However, the proteins bound to calcareous corpuscles in situ have not been studied. The present study was undertaken to identify the proteins on calcareous corpuscles. Calcareous corpuscles were purified from the plerocercoids (= spargana) of Spirometra erinacei, and serially dissolved using 0.1 M sulfamic acid solution. Collected supernatants were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining. The results showed that only the fraction remaining after the 19th dissolved fraction contained proteins. A total of 20 protein molecules were detected in gel, with major bands at 56, 53, 46, 40, 35, 29, 28, 24.5, 21, 19, 16, 13, 10 and 8 kDa. In particular, the proteins corresponding to the 21 and 16 kDa bands were most abundant. Our results demonstrated for the first time the protein contents of the calcareous corpuscles of spargana. Further studies on the functions of these proteins are required.

• Parasites, Hosts and Diseases
• /
• v.46 no.4
• /
• pp.279-283
• /
• 2008

To examine humoral immune responses in the host, we measured serum antibody levels in different strains of mice (ICR, BALB/c, and C3H) experimentally infected with Neodiplostomum seoulense. Specific IgG antibody levels were increased remarkably with little difference among 3 strains of mice infected with N. seoulense from day 7 to 35 post-infection. More target proteins of adult parasites reacted with IgG at the time when the worm recovery decreased compared with other times. More than 20 protein bands, from 14 kDa to 94 kDa in size, were separated from the crude antigen of N. seoulense adults by SDS-PAGE, and among them 26, 30, 35, 43, 54, 67, and 94 kDa proteins were the major antigenic proteins. The results suggest that significant IgG antibody responses occur against N. seoulense in mice and this may be related with expulsion of worms.

• BMB Reports
• /
• v.43 no.11
• /
• pp.726-731
• /
• 2010

We report the tissue-specific distribution of chitinolytic activity in Korean ginseng root and characterize two 31-kDa chitinolytic enzymes. These two enzymes (SBF1 and SBF2) were purified 70- and 81-fold with yields of 0.75 and 1.25%, respectively, and exhibited optimal pH and temperature ranges of 5.0-5.5 and 40-$50^{\circ}C$. With [$^3H$]-chitin as a substrate, $K_m$ and $V_{max}$ values of SBF1 were 4.6 mM and 220 mmol/mg-protein/h, respectively, while those of SBF2 were 7.14 mM and 287 mmol/mg-protein/h. The purified enzymes showed markedly less activity with p-nitrophenyl-N-acetylglucosaminide and fluorescent 4-methylumbelliferyl glycosides of D-N-acetylglucosamine oligomers than with [$^3H$]-chitin. End-product inhibition of both enzymes demonstrated that both are endochitinases with different N-acetylglucosaminidase activity. Furthermore, the $NH_2$-terminal sequence of SBF1 showed a high degree of homology with other plant chitinases whereas the $NH_2$-terminal amino acid of SBF2 was blocked.

• The Korean Journal of Ecology
• /
• v.24 no.1
• /
• pp.35-43
• /
• 2001

Accumulation, elimination and subcellular distribution of heavy metals in Littorina brevicula exposed to cadmium and zinc separately and concurrently were investigated. When the winkles had been exposed to 400 ㎍/L CdCl₂ and 3000 ㎍/l ZnSO₄ separately for 90 days, each of the metal body burden in the whole sofl parts increased in proportion to time of exposure until 70 days. But it didn't increase after 70 days. But when the winkles had been exposed to cadmium and zinc simultaneously, cadmium body burden decreased but zinc body burden increased as compared to the winkles exposed to each of the metal. We also found that cadmium accumulated in the winkles was not depurated for 42 days, but zinc accumulated in them was depurated. Especially, zinc was depurated faster when they had been exposed to mixture of cadmium and zinc. After the winkles had been exposed to cadmium and zinc separately for 70 days, about 60% cadmium of the total body burden was associated with the soluble fraction, while about 75% zinc of the total body burden was associated with insoluble fraction. And these trends of metal partitioning did not alter when the winkles had been exposed to metal mixture. After the soluble fraction applied to gel-filtration chromatography column, the distribution patterns of cadmium and zinc associated with proteins or ligands were different each other. Most of cadmium (＞90%) in the soluble fraction was bound to MBP-1 (Metal-binding protein-1), about 6.5 kDa), while zinc was distributed evenly to HMW (High molecular weight fraction, >60 kDa), MBP-1, MBP-2 (about 5 kDa), LMW (Low molecular weight fraction, <1 kDa).

• Proceedings of the Korean Biophysical Society Conference
• /
• 2003.06a
• /
• pp.43-43
• /
• 2003

Large-conductance $Ca^{2+}$-actived $K^{+}$ channels ($BK_{Ca}$ channels) play a key role in setting the pace of contractile activity in muscle and are involved in the regulation of neurotransmitter release in neuron. $BK_{Ca}$ channels are activated by depolarizing membrane potential and the elevated level of intracellular calcium. Using yeast-two hybrid assay, we have identified a novel protein interacting with the cytosolic carboxyl terminus of rSlo, the brain isoform of rat large-conductance $Ca^{2+}$-activated $K^{+}$ channel $\alpha$-subunit. The novel gene encodes 51 kDa protein and is named as SIRK(rSlo-interacting RGS-like protein). SIRK is expressed in various tissues and localized in the cytosolic and the membrane fraction. Biochemical and immunological studies indicated that SIRK physically interacted with the cytosolic region of rSlo. To investigate whether SIRK can modulate the activity of rSlo, GFP-fused SIRK and rSlo were transiently transfected into COS-7 cells and the effects of SIRK was studied using electrophysiological means. We concluded that the overexpression of SIRK alters the surface expression of rSlo channel with only a limited effect on the biophysical characteristics of the channel.the channel.

• Korean Journal of Pharmacognosy
• /
• v.40 no.1
• /
• pp.13-17
• /
• 2009

It was previously reported that yeast elicitor transiently increased oleanolic acid and ursolic acid in Scutellaria baicalensis suspension cultures and also doubled phospholipase $A_2$ ($PLA_2$) activity. Thus, $PLA_2$ was purified from the soluble fractions of S. baicalensis suspension cultures and the characters of the purified $PLA_2$ were identified. The $PLA_2$ was purified about 160 times compared with the starting soluble-protein extract from S. baicalensis suspension culture cells. The purified protein showed a molecular mass of about 43 kDa by SDS-PAGE. The purified plant $PLA_2$ had a neutral pH optimum (pH 7.0) and required $Ca^{2+}$ for activity. The $PLA_2$ activity was inhibited by mammalian $PLA_2$ inhibitors such as 5,8,11,14-eicosatetraynoic acid(ETYA) and arachidonyl trifluoromethyl ketone ($AACOCF_3$).

• KSBB Journal
• /
• v.15 no.2
• /
• pp.145-149
• /
• 2000

Methyl mercaptan oxidase was isolated and purified from Thiobacillus thiooxidans KCTC2505 for the detection of mercaptans. T The produre of purification involved DEAE-Sephacel and Superose 12 column chromatographies with recovery yields of 40 a and 6.3%, and specific activity of 19.7 and 80.1 units/mg-protein, respectively. The molecular weight of purified methyl m mercaptan oxidase was determined to be 68.1 kDa by SDS-PAGE. The extract from DEAE-Sephacel column chromatography h had a high activity in oxidizing methyl mercaptan to produce formaldehyde which can be easily detected by purpald-coloring m method. Optimum temperature for activity was observed at $43^{\circ}C$. This enzyme was activated by $NH_4CI and (NH_4)_2S0_4$, and | inhibited by KCI and NaC!.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.9
• /
• pp.1383-1390
• /
• 2019

In this study, we expressed cotA laccase from Bacillus subtilis on the surface of B. subtilis spores for efficient decolorization of synthetic dyes. The cotE, cotG, and cotY genes were used as anchoring motifs for efficient spore surface display of cotA laccase. Moreover, a $His_6$ tag was inserted at the C-terminal end of cotA for the immunological detection of the expressed fusion protein. Appropriate expression of the CotE-CotA (74 kDa), CotG-CotA (76 kDa), and CotY-CotA (73 kDa) fusion proteins was confirmed by western blot. We verified the surface expression of each fusion protein on B. subtilis spore by flow cytometry. The decoloration rates of Acid Green 25 (anthraquinone dye) for the recombinant DB104 (pSDJH-EA), DB104 (pSDJH-GA), DB104 (pSDJH-YA), and the control DB104 spores were 48.75%, 16.12%, 21.10%, and 9.96%, respectively. DB104 (pSDJH-EA) showed the highest decolorization of Acid Green 25 and was subsequently tested on other synthetic dyes with different structures. The decolorization rates of the DB104 (pSDJH-EA) spore for Acid Red 18 (azo dye) and indigo carmine (indigo dye) were 18.58% and 43.20%, respectively. The optimum temperature for the decolorization of Acid Green 25 by the DB104 (pSDJH-EA) spore was found to be $50^{\circ}C$. Upon treatment with known laccase inhibitors, including EDTA, SDS, and $NaN_3$, the decolorization rate of Acid Green 25 by the DB104 (pSDJH-EA) spore decreased by 23%, 80%, and 36%, respectively.

• Molecules and Cells
• /
• v.43 no.9
• /
• pp.821-830
• /
• 2020

Altered dendritic morphology is frequently observed in various neurological disorders including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but the cellular and molecular basis underlying these pathogenic dendritic abnormalities remains largely unclear. In this study, we investigated dendritic morphological defects caused by dipeptide repeat protein (DPR) toxicity associated with G4C2 expansion mutation of C9orf72 (the leading genetic cause of ALS and FTD) in Drosophila neurons and characterized the underlying pathogenic mechanisms. Among the five DPRs produced by repeat-associated non-ATG translation of G4C2 repeats, we found that arginine-rich DPRs (PR and GR) led to the most significant reduction in dendritic branches and plasma membrane (PM) supply in Class IV dendritic arborization (C4 da) neurons. Furthermore, expression of PR and GR reduced the number of Golgi outposts (GOPs) in dendrites. In Drosophila brains, expression of PR, but not GR, led to a significant reduction in the mRNA level of CrebA, a transcription factor regulating the formation of GOPs. Overexpressing CrebA in PR-expressing C4 da neurons mitigated PM supply defects and restored the number of GOPs, but the number of dendritic branches remained unchanged, suggesting that other molecules besides CrebA may be involved in dendritic branching. Taken together, our results provide valuable insight into the understanding of dendritic pathology associated with C9-ALS/FTD.

• Molecules and Cells
• /
• v.43 no.10
• /
• pp.870-879
• /
• 2020

Dendrites require precise and timely delivery of protein substrates to distal areas to ensure the correct morphology and function of neurons. Many of these protein substrates are supplied in the form of ribonucleoprotein (RNP) complex consisting of RNA-binding proteins (RBPs) and mRNAs, which are subsequently translated in distal dendritic areas. It remains elusive, however, whether key RBPs supply mRNA according to local demands individually or in a coordinated manner. In this study, we investigated how Drosophila sensory neurons respond to the dysregulation of a disease-associated RBP, Ataxin-2 (ATX2), which leads to dendritic defects. We found that ATX2 plays a crucial role in spacing dendritic branches for the optimal dendritic receptive fields in Drosophila class IV dendritic arborization (C4da) neurons, where both expression level and subcellular location of ATX2 contribute significantly to this effect. We showed that translational upregulation through the expression of eukaryotic translation initiation factor 4E (eIF4E) further enhanced the ATX2-induced dendritic phenotypes. Additionally, we found that the expression level of another disease-associated RBP, fragile X mental retardation protein (FMRP), decreased in both cell bodies and dendrites when neurons were faced with aberrant upregulation of ATX2. Finally, we revealed that the PAM2 motif of ATX2, which mediates its interaction with poly(A)-binding protein (PABP), is potentially necessary for the decrease of FMRP in certain neuronal stress conditions. Collectively, our data suggest that dysregulation of RBPs triggers a compensatory regulation of other functionally-overlapping RBPs to minimize RBP dysregulation-associated aberrations that hinder neuronal homeostasis in dendrites.