• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.4
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• pp.237-243
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• 2001

Substantial progress has been made towards understanding the folding mechanisms of proteins in virto and in vivo even though the general rules governing such folding events remain unknown. This paper reviews current folding models along with experimental approaches used to elucidate the folding pathways. Protein misfolding is discussed in relation to disease states, such as amyloidosis, and the recent findings on the mechanism of converting normally soluble proteins into amyloid fibrils through the formation of intermediates provide an insight into understanding the pathogenesis of amyloid formation and possible cules for the development of therapeutic treatments. Finally, some commonly adopted refolding strategies developed over the part decade are summarized.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.247-254
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• 2015

In this presentation, I describe the expression and purification of the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a commercially available double cistronic vector, pACYCDuet-1, to express the receptor heterodimer in a single cell as the soluble form. I describe here the expression and characterization of a biologically active heterodimer composed of the liver X receptor β-ligand binding domain and retinoid X receptor α-ligand binding domain. Although many of these proteins were previously seen to be produced in E. coli as insoluble aggregates or "inclusion bodies", I show here that as a form of heterodimer they can be made in soluble forms that are biologically active. This suggests that co-expression of the liver X receptor β-ligand binding domain with its binding partner improves the solubility of the complex and probably assists in their correct folding, thereby functioning as a type of molecular chaperone.

• The Korean Journal of Malacology
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• v.18 no.1
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• pp.15-21
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• 2002

The kidney of bivalve mollusks often contains remarkably high concentrations of both essential and non-essential metals and perform regulating and detoxicating activities. The kidney has also been proposed as a biological indicator for radioactive as well as for stable metals in the sea. The present study of the Antarctic clam, Laternula elliptica, concerns the functional morphology of the kidney epithelium, which contains highly accumulated heavy metals. The immunohistochemical and ultrastructural study was undertaken in order to find out the localization of metallothionein and heavy metals accumulated in the kidney of Laternula elliptica. In the immunohistochemical investigation, an intense metallothionein immunostaining reaction was found in the epithelial cells of the kidney of Laternula elliptica. Transmission electron microscopy showed that the epithelial cells contained numerous electron-dense inclusion bodies which were considered to be accumulated heavy metals.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.352-355
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• 2004

Heliothis zea (HzAM1) insect cells were immobilized in microspheres by sodium-cellulosesulfate (NaCS) and polydiallyldimethylammoniumchloride (PDADMAC). The highest HzAMl cell density was $7.5{\times}10^7$ cells/mL in the microspheres. After infection of the immobilized cells by Heliothis zea single nuclear polyhedrosis virus (HzSNPV), the highest concentration of HzSNPV (polyhedral inclusion bodies: PIBs) produced was $2.87{\times}10^{10}$ PIBs/mL in the microspheres.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.500-504
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• 2005

Fusion ferritin (heavy chain ferritin, $F_H+$ light chain ferritin, $F_L$), an iron-binding protein, was primarily purified from recombinant Escherichia coli by two-step sonications with urea [1]. Unfolded ferritin was refolded by gel filtration chromatography (GFC) with refolding enhancer, where 50 mM Na-phosphate (pH 7.4) buffer containing additives such as Tween 20, PEG, and L-arginine was used. Ferritin is a multimeric protein that contains approximately 20 monomeric units for full activity. Fusion ferritin was expressed in the form of inclusion bodies (IBs). The IBs were initially solubilized in 4 M urea denaturant. The refolding process was then performed by decreasing the urea concentration on the GFC column to form protein multimers. The combination of the buffer-exchange effect of GFC and the refolding enhancers in refolding buffer resulted in an efficient route for producing properly folded fusion ferritin.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2607-2612
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• 2010

Human tissue-type plasminogen activator (tPA) is a valuable thrombolytic agent used to successfully treat acute myocardial infarction, thromboembolic stroke, peripheral arterial occlusion, and venous thromboembolism. Recombinant tPA is accumulated as an inactive form in inclusion bodies of E. coli and is refolded in vitro, which is accompanied by extensive aggregation. In the present study, a tPA protease domain was expressed in an active soluble form in the cytosol of E. coli Rosetta-gami cells, which allowed disulfide bond formation and supplied the tRNA molecules required for six rarely used codons in E. coli. This strategy increased the amount of soluble protease domain protein and avoided the cumbersome refolding process. The purified protease domain not only degraded tPA substrate peptides but also formed a covalently bound complex with plasminogen activator inhibitor-1, as does full-length tPA. Soluble expression and purification of tPA domains may aid in functional analyses of this multi-domain protein, which has been implicated in many physiological and pathological processes.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.41-48
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• 1995

To increase the folding efficiency of proinsulin, we have designed a series of mini-proinsulins having the central C-peptide region replaced with sequences forming reverse turns. These proteins were produced as fusion proteins in E. coli in the form of inclusion bodies. After isolation process of the sulfonated mini-proinsulins, the subsequent refolding experiments indicate that the mini-proinsulins, with non-native penta-peptide sequences inserted between two of the enzyme processing sites, show substantially increased folding yields compared with the proinsulin. The correct disulfide connections were verified by fingerprint analysis using Glu-C endoproteinase. These novel mini-proinsulins could be used for the study of folding mechanism of proinsulin.

• Korean Journal of Veterinary Pathology
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• v.3 no.1
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• pp.61-64
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• 1999

A dead marten(Martes melampus) showing cough, ataxia and convulsion of hind limb followed by seizures, was submitted for diagnosis to the Pathology Division of the National Veterinary Research and Quarantine Service. In the gross lesions, lung was congested and consolidated and meningeal blood vessels were mildly congested. Histopathologic findings were diffuse interstitial pneumonia and nonsuppurative meningoencephalitis with malacia of cerebral and cerebellar white matter. Eosinophilic inclusion bodies were observed in neurons and astrocytes and oligodendroglial cells of brain and transitional epithelium of kidney. Using FA test and PCR method, specific antigens of canine distemper virus were demonstrated in the brain.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.202-205
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• 2005

Our previous study showed that the overexpression of carboxypeptidase Y (CPY) of Saccharomyces cerevisiae in Escherichia coli resulted in the formation of insoluble inclusion bodies. To produce soluble CPY, we designed a novel Pichia pastoris expression system, in which the following were inserted into expression vectors: three different signal sequences derived from the mating factor a1 of S. cerevisiae, an inulinase of Kluyveromyces marxianus, and the endogenous signal sequence of CPY. The expression vector pHIL-D2-SSinul-proCPY was the most effective in the production of proCPY among the vectors examined. The purified active CPY was obtained from proCPY by treating with proteinase K, followed by QExcellose ion-exchange column chromatography.

• Journal of Microbiology
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• v.34 no.4
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• pp.370-373
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• 1996

Three strains (KW-1, KW-14, KW-15) of Bacillus thuringiensis were isolated from soil in Wonju area and characterized. The three strains produced parasporal inclusion bodies (crystals) and spores in their cells. The KW-1 strain produces spherical crystals. The crystals of strain KW-14 are bipyramidal crystal. The KW-15 strain harbors irregular crystals. Only minor biochemical characteristics of the three isolates were different and distinctive, however general characteristics were similar to the known serotypes of B. thuringiensis. Three strains were resistant to penicilin G, oxacillin and cephalothin. Three strains were highly toxic to Bombyx mori larvae, but not to the Culex pipiens larvae.