• KSBB Journal
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• v.16 no.6
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• pp.626-631
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• 2001

Lactobacilli have been considered to play important roles in the health of human vagina. They secrete inhibitory substances to prevent vaginal infection by pathogenic organisms. In a previous study, we have isolated several lactobacilli from Korean woman and one of them (KLB46) was selected and indentified as Lactobacillu crispatus which showed high antimicrobial activity. In this study. cold adaptation prior to subsequent stresses exposure was examined whether L. crispatus KLB46 maintain the viability better than the non-adapted calls under stresses. For pharmaceutical formulation, the lyophilization process is required where stresses such as freezing/thawing and dehydration are routinely applied. Formulated L. crispatus KLB46 can be used for ecological treatment of bacterial vaginosis. The response of cold-adapted cells to other environmental stresses such as acid, heat, ethanol, NaCl, and H$_2$O$_2$ was also examined. The results showed that cold-adapted cells maintained higher survival rate compared with the non-adapted cells (freezing-thawing. 3-folds; dehydration: 3-folds; acid, 3-folds; heat, 10-folds). However, we did net observe any positive effect of cold adaptation on other stresses such as ethanol, NaCl and H$_2$O$_2$. When chloramphenicol was added during cold adaptation, adaptation effect was abolished. This confirms that de novo protein synthesis is necessary during the adaptation process. Moreover, we have identified cold shock protein homolog that codes for a major cold shock protein by PCR amplification using degenerate primers.

• Korean journal of applied entomology
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• v.51 no.3
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• pp.255-263
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• 2012

High frequency sounds disrupt physiological processes, such as feeding behavior, development and immune responses of Spodoptera exigua. We analyzed high frequency sounds with respect to biochemical changes in S. exigua. High frequency sound (5,000 Hz, 95 dB) suppressed protein synthesis and secretion of midgut epithelium. It also significantly inhibited a digestive enzyme activity of phospholipase $A_2$. The gene expression of three different heat shock proteins and apolipophorin III was altered, particularly in midgut tissue in response to high frequency sound treatments. High frequency sound treatments significantly increased sugar and lipid levels in hemolymph plasma. These results suggest that high frequency sounds are a physiological stress that induces biochemical changes in S. exigua.

• Korean Journal of Animal Reproduction
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• v.26 no.4
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• pp.311-320
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• 2002

The objective of this study was to assess the developmental potential in vitro produced embryos frozen-thawed with the various containers, and also examined expression and localization of heat shock protein 70 at these embryos. For the vitrification, 2-cell, 8-cell and blastocyst stage embryos produced by in vitro fertilization (IVF) and nuclear transfer (NT) were exposed the ethylene glycol 5.5 M freezing solution (EC 5.5) for 30 sec, loaded on each containers such EM grid, straw and cryo-loop, and then immediately plunged into liquid nitrogen. Thawed embryos were serially diluted in sucrose solution, each for 1 min. and cultured in CRI-aa medium. Survival rates of the vitrification production were assessed by re-expanded, hatched blastocysts. There were no differences in the survival rates of IVF using EM grid and cryo-loop. However, survival rates by straw were relatively lower than other containers. The use of cryo-loop resulted in only survival of nuclear transferred embryos (43.7%). Also, there embryos after IVF or NT were analysed by semi-quantitive reverse transcription-polymerase chain reaction (RT- PCR) methods for hsp 70 mRNA expression. Results revealed the expression of hsp 70 mRNh were higher thawed embryos than control embryos. Immunocytochemistry used to localize the hsp 70 protein in embryos. Two and 8-cell embryos derived under control condition was evenly distributed in the cytoplasm but appeared as aggregates in some frozen-thawed embryos. However, in the control, blastocysts displayed aggregate signal while Hsp70 in frozen-thawed blastocysts appeared to be more uniform In distribution. Therefore, this result suggests that the exploiting Hsp 70 in the early embryos may be role for protection of stress condition for increase viability of embryos within IVF, NT and there frozen-thawed embryos.

• The Microorganisms and Industry
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• v.25 no.1
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• pp.2-9
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• 1999

A study was made on enzymes of carbohydrate metabolism in T. concretivorus grown with and without glucose. The present results show that T. concretivorus possesses high activities of pentose shunt pathway and related enzymes, glucokinase, G-6-P dehydrogenase, 6-PG dehydrogenase, and phosphoglucoisomerase, but low activities of enzymes unique to EMP(fructose-1,6-diphosphate aldolase). Although the synthesis of the latter enzymes remains largely unaffected by the growth enviroment, that of the former is stimulated by glucose. And the failure to detect ED pathway enzymes in cells grown in thiosulate or thiosulfate-glucose medium eliminates the ED pathway as a significant route of glucose catabolism in T.concretivorus. These results suggest that pentose shunt pathway performs an energetic role in glucose metabolism by T.concretivorus with EMP as a subway. The absence of ED pathway and the presence of pentose shunt pathway which is the major route of catabolism in T.concretivorus are similar to those of other obligately chemolitho-trophic thiobacilli. The G-6-P and 6-PG dehydrogenase are both NAD and NADP specific, but MAD predominant. However, the 3-PGAL dehydrogenase is only NAD specific. Since the specific activity of 3-PGAL generated from glucose is converted mainly into pyruvate which is channeled into the TCA cycle. All enzymes of the TCA cycle tested and NADH oxidase are detected in the cells of T.concretivorus grown in thiosulfate. The specific activities of fumarase and isocitrate dehydrogenase are high and others are low. The presence of two isocitrate dehydrogenase (NAD-and NADP-linked) may have important regulatory function for this organism. The activity of NAD-oxidase, which is implicated in the energy generating metabolism, was very high in the crude cell-free extract of T.concretivorus, recording 55.11 m.mu. mole/min/mg protein. This well coincides with the fact that activities of NAD-linked G-6-P dehydrogenase, 6-PG dehydrogenase and 3-PGAL dehydrogenase were high.

• Journal of Life Science
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• v.8 no.2
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• pp.226-226
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• 1998

Discovery of molecular chaperone has stimulate cell biologists and thus made it possible to re-examine the processes whereby proteins achieve and maintain their functional conformations within living cells. the term ‘Molecular chaperone’ was first coined to describe one particular protein involved in the assembly of nucleosomes, but the term has now been extended to describe the function of a wide variety of proteins that assist protein transport across membranes, folding of nascent polypeptide, the assembly and disassembly of oligomeric structures, and the recovery or removal of proteins damaged by various environmental stresses including heat shock. Progress of molecular chaperone research is still limited by the lack of 3-dimensional structural information and detailed interacts with taget proteins in the cell. However, several laboratories around the world are attempting to extend our knowledge on the functions of molecular chaperone, and such efforts seem justified to finally provide the answers to the most burning questions shortly.

• Molecules and Cells
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• v.43 no.8
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• pp.694-704
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• 2020

HslUV is a bacterial heat shock protein complex consisting of the AAA+ ATPase component HslU and the protease component HslV. HslV is a threonine (Thr) protease employing the N-terminal Thr residue in the mature protein as the catalytic residue. To date, HslUV from Gram-negative bacteria has been extensively studied. However, the mechanisms of action and activation of HslUV from Gram-positive bacteria, which have an additional N-terminal sequence before the catalytic Thr residue, remain to be revealed. In this study, we determined the crystal structures of HslV from the Gram-positive bacterium Staphylococcus aureus with and without HslU in the crystallization conditions. The structural comparison suggested that a structural transition to the symmetric form of HslV was triggered by ATP-bound HslU. More importantly, the additional N-terminal sequence was cleaved in the presence of HslU and ATP, exposing the Thr9 residue at the N-terminus and activating the ATP-dependent protease activity. Further biochemical studies demonstrated that the exposed N-terminal Thr residue is critical for catalysis with binding to the symmetric HslU hexamer. Since eukaryotic proteasomes have a similar additional N-terminal sequence, our results will improve our understanding of the common molecular mechanisms for the activation of proteasomes.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1717-1722
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• 2008

The 70 kDa heat-shock protein (Hsp70) involved in various cellular functions, such as protein folding, translocation and degradation, regulates apoptosis in cancer cells. Recently, it has been reported that the green tea flavonoid (−)-epigallocatechin 3-gallate (EGCG) induces apoptosis in numerous cancer cell lines and could inhibit the anti-apoptotic effect of human Hsp70 ATPase domain (hATPase). In the present study, docking model between EGCG and hATPase was determined using automated docking study. Epi-gallo moiety in EGCG participated in hydrogen bonds with side chain of K71 and T204, and has metal chelating interaction with hATPase. Hydroxyl group of catechin moiety also participated in metal chelating hydrogen bond. Gallate moiety had two hydrogen bondings with side chains of E268 and K271, and hydrophobic interaction with Y15. Based on this docking model, we determined two pharmacophore maps consisted of six or seven features, including three or four hydrogen bonding acceptors, two hydrogen bonding donors, and one lipophilic. We searched a flavonoid database including 23 naturally occurring flavonoids and 10 polyphenolic flavonoids with two maps, and myricetin and GC were hit by map I. Three hydroxyl groups of B-ring in myricetin and gallo moiety of GC formed important hydrogen bonds with hATPase. 7-OH of A-ring in myricetin and OH group of catechin moiety in GC are hydrogen bond donors similar to gallate moiety in EGCG. From these results, it can be proposed that myricetin and GC can be potent inhibitors of hATPase. This study will be helpful to understand the mechanism of inhibition of hATPase by EGCG and give insights to develop potent inhibitors of hATPase.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.209-219
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• 2013

Heat shock protein 90 (Hsp90) is a molecular chaperone that assists protein folding and contributes to the stability of various proteins. It also stabilizes a number of proteins involved in tumor growth to consider it as a promising target for the treatment of cancer. Natural products have been a rich source of agents of value in medicine, therefore discovering lead compounds from them is one of important strategy in the drug development. In this regard, geldanamycin, radicicol, novobiocin and celastrol have been utilized as leads for the development of Hsp90 inhibitory anticancer agents. This review summerizes recent findings of natural products as Hsp90 inhibitiors. The Hsp90 inhibitory activities, mode of actions on Hsp90 and cytotoxicities on human cancer cell lines of natural products including bulgarialactone B, curcumin, (-)-gambogic acid, quercetin, sansalvamide A, silybin, and withaferin A were discussed.

• Animal Bioscience
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• v.36 no.5
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• pp.704-709
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• 2023

Objective: In tropical, subtropical and arid zones, heat stress is the main cause of productivity reduction in cattle. When climate stressors occur, animals become thermal adapted through differential expression of some genes, including heat shock proteins (HSP) family. The aim of this study was to determine levels of expression of HSP60, HSP70, and HSP90 genes in Simmental cattle raised in tropical environments of Mexico. Methods: In this study, expression of HSP60, HSP70, and HSP90 genes was analyzed in 116 Simmental cattle from three farms with tropical climate located in western Mexico. Animals were sampled twice a day, in the morning and noon. Gene expression was evaluated by quantitative polymerase chain reaction using probes marked with fluorescence. The MIXED procedure of SAS with repeated measures was used for all statistical analysis. Results: HSP60 gene expression differences were found for sex (p = 0.0349). HSP70 gene differences were detected for sampling hour (p = 0.0042), farm (p<0.0001), sex (p = 0.0476), and the interaction sampling hour×farm (p = 0.0002). Gene expression differences for HSP90 were observed for farm (p<0.0001) and year (p = 0.0521). HSP70 gene showed to be a better marker of heat stress than HSP60 and HSP90 genes. Conclusion: Expression of HSP70 gene in Simmental herds of the tropical region of western México was different during early morning and noon, but the expression of the HSP60 and HSP90 genes was similar. Identification of resilient animals to heat stress will be useful in the genetic improvement of the Simmental breed.

• BMB Reports
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• v.49 no.6
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• pp.337-343
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• 2016

Understanding of trafficking, processing, and degradation mechanisms of amyloid precursor protein (APP) is important because APP can be processed to produce β-amyloid (Aβ), a key pathogenic molecule in Alzheimer's disease (AD). Here, we found that APP contains KFERQ motif at its C-terminus, a consensus sequence for chaperone-mediated autophagy (CMA) or microautophagy which are another types of autophagy for degradation of pathogenic molecules in neurodegenerative diseases. Deletion of KFERQ in APP increased C-terminal fragments (CTFs) and secreted N-terminal fragments of APP and kept it away from lysosomes. KFERQ deletion did not abolish the interaction of APP or its cleaved products with heat shock cognate protein 70 (Hsc70), a protein necessary for CMA or microautophagy. These findings suggest that KFERQ motif is important for normal processing and degradation of APP to preclude the accumulation of APP-CTFs although it may not be important for CMA or microautophagy.