• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.17 no.1
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• pp.27-49
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• 1987

Using ³H-proline as a radioactive tracer, the relationship between the ultrastructural differentiation and the site of protein synthesis has been investigated in developing red blood corpuscles. The general ultra-structure of erythropoietic cells in differentiation after 60 minutes of in vitro labeling has confirmed the results from previous investigations by Bessis, M., Thiery, J. and others. In dividing nuclei more than two-thirds of the labeling were present at the interface between heterochromatin and euchromatin. In less differentiated cells most of the grains in interphase cells was localized over the nucleus. As the cells continued to develope beyond a stage where cytoplasmic density was clearly increased over other cell lines in bone marrow, the majority of grains localized over the cytoplasmic area was decreased in more mature cells, as judged by the density of cytoplasm, and the structural changes in mitochondria, Golgi complex and polysomal configurations. These results show; 1) that the cytoplasm of erythroblast series does not change under in vitro conditions employed in the study; 2) that protein synthesis in the nucleus occurs largely at the interface between euchromatin and heterochromatin in active nuclei; and 3) that cytoplasmic synthesis of proteins continues to take place well into the normoblast stage solong as the physically visible polysomes are present in maturing red blood corpuscles.

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.139-145
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• 2022

Protein glycosylation is a common post-translational modification by non-template-based biosynthesis. In fungal biotechnology, which has great applications in pharmaceuticals and industries, the importance of research on fungal glycoproteins and glycans is accelerating. In particular, the importance of quantitative analysis of fungal glycans is emerging in research on the production of filamentous fungal proteins by genetic modification. Reliable mass spectrometry-based techniques for quantitative glycomics have evolved into chemical, enzymatic, and metabolic stable isotope labeling methods. In this study, we intend to expand quantitative glycomics by metabolic isotope labeling of glycans in Aspergillus niger, a filamentous fungus model, by the MILPIG method. We demonstrate that incubation of filamentous fungi in a culture medium with carbon-13 labeled glucose (1-¹³C₁) efficiently incorporates carbon-13 into N-linked glycans. In addition, for quantitative validation of this method, light and heavy glycans are mixed 1:1 to show the performance of quantitative analysis of various N-linked glycans simultaneously. We have successfully quantified fungal glycans by MILPIG and expect it to be widely applicable to glycan expression levels under various biological conditions in fungi.

• Animal Bioscience
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• v.35 no.1
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• pp.96-104
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• 2022

Objective: Sarcoplasmic proteins include proteins that play critical roles in biological processes of living organisms. How seasons influence biological processes and meat quality of postmortem muscles through the regulation of protein phosphorylation remain to be investigated. In this study, the phosphorylation of sarcoplasmic proteins in pork longissimus muscle was investigated in four seasons. Methods: Sarcoplasmic proteins were extracted from 40 pork carcasses (10 for each season) and analyzed through ProQ Diamond staining for phosphorylation labeling and Sypro Ruby staining for total protein labeling. The pH of muscle, contents of glycogen and ATP were measured at 45 min, 3 h, and 9 h postmortem and the water (P_2b, P₂₁, and P₂₂) was measured at 3 h and 9 h. Results: A total of 21 bands were detected. Band 8 (heat shock cognate 71 kDa protein; heat shock 70 kDa protein 1B) had higher phosphorylation level in summer than that in other seasons at 45 min postmortem. The phosphorylation levels of 3 Bands were significantly different between fast and normal pH decline groups (p<0.05). The phosphorylation levels of 4 bands showed negative associations with immobilized water (P₂₁) and positive association with free water (P₂₂). Conclusion: The phosphorylation levels of sarcoplasmic proteins involved in energy metabolism and heat stress response at early postmortem time differed depending on the seasons. These proteins include heat shock protein 70, pyruvate kinase, phosphoglucomutase-1, glucose-6-phosphate isomerase, and carbonic anhydrase 3. High temperatures in summer might result in the phosphorylation of those proteins, leading to pH decline and low water holding capacity.

• Korean Journal of Community Nutrition
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• v.9 no.5
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• pp.636-643
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• 2004

The purpose of this study was to investigate school dietitians' perception on nutrition labelling of processed and packaged foods in the Incheon area. This study was carried out through a self-administered questionnaire and the subjects were 203 school dietitians. The results were summarized as follows. Most of the subjects checked nutrition labeling of processed and packaged foods when they purchased these foods for school lunch. However, the main reason for their checking nutrition labeling of processed and packaged foods was not for nutrition but for food safety. There were significant differences in the subjects' understanding and trust on nutrition labeling of processed and packaged foods by employment school. The scores of the subjects' satisfaction, understanding and trust on nutrition labeling of processed and packaged foods were not high. There were significant differences in the subjects' perception and concern about content information on nutrition labeling of domestic processed and packaged foods by employment school. Most of the subjects answered that it is almost necessary or very necessary to implement nutrition labelling of processed and packaged foods. Also their most preferred method of nutrition labelling was to label nutrient content. As the most important nutrient and functional component necessary for nutrition labelling, they answered energy, mineral such as calcium and iron, protein, total fat, cholesterol, vitamin, sodium and dietary fiber in order. As the major prerequisite task for the implementation of nutrition labelling, they answered formulation of nutrition labelling-related rules, and education and motivation for consumer, Therefore, it is necessary to activate the mandatory nutrition labelling of the processed and packaged foods and to prepare its consumer education program for school dietitian.

• Journal of the Korean Magnetic Resonance Society
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• v.19 no.3
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• pp.137-142
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• 2015

NMR-based structural studies on membrane proteins are appreciated quite challenging due to various reasons, generally including the narrow dispersion of NMR spectra, the severe peak broadening, and the lack of long range NOEs. In spite of the poor biophysical properties, structural studies on membrane proteins have got to go on, considering their functional importance in biological systems. In this review, we provide a simple overview of the techniques generally used in structural studies of membrane proteins by solution NMR, with experimental examples of a helical membrane protein, caveolin 3. Detergent screening is usually employed as the first step and the selection of appropriate detergent is the most important for successful approach to membrane proteins. Various tools can then be applied as specialized NMR techniques in solution that include sample deteuration, amino-acid selective isotope labeling, residual dipolar coupling, and paramagnetic relaxation enhancement.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1429-1433
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• 2006

Application of recombinant protein production and particularly their isotopic enrichment has stimulated development of a range of novel multidimensional heteronuclear NMR techniques. Peptides in most cases are amenable to assignment and structure determination without the need for isotopic labeling. However, there are many cases where the availability of $^{15}N$ and/or $^{13}C$ labeled peptides is useful to study the structure of peptides with more than 30 residues and the interaction between peptides and membrane. CRAMP (Cathelicidin-Related AntiMicrobial Peptide) was identified from a cDNA clone derived from mouse femoral marrow cells as a member of cathelicidin-derived antimicrobial peptides. CRAMP was successfully expressed as a GST-fused form in E. coli and purified using affinity chromatography and reverse-phase chromatography. The yield of the CRAMP was 1.5 mg/l 1. According to CD spectra, CRAMP adopted ${\alpha}$-helical conformation in membrane-mimetic environments. Isotope labeling of CRAMP is expected to make it possible to study the structure and dynamic properties of CRAMP in various membrane systems.

• Journal of Periodontal and Implant Science
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• v.46 no.1
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• pp.2-9
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• 2016

Purpose: Porphyromonas gingivalis and Tannerella forsythia have been implicated as the major etiologic agents of periodontal disease. These two bacteria are frequently isolated together from the periodontal lesion, and it has been suggested that their interaction may increase each one's virulence potential. The purpose of this study was to identify proteins on the surface of these organisms that are involved in interbacterial binding. Methods: Biotin labeling of surface proteins of P. gingivalis and T. forsythia and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was performed to identify surface proteins involved in the coaggregating activity between P. gingivalis and T. forsythia. Results: It was found that three major T. forsythia proteins sized 161, 100, and 62 kDa were involved in binding to P. gingivalis, and P. gingivalis proteins sized 35, 32, and 26 kDa were involved in binding to T. forsythia cells. Conclusions: LC-MS/MS analysis identified one T. forsythia surface protein (TonB-linked outer membrane protein) involved in interbacterial binding to P. gingivalis. However, the nature of other T. forsythia and P. gingivalis surface proteins identified by biotin labeling could not be determined. Further analysis of these proteins will help elucidate the molecular mechanisms that mediate coaggregation between P. gingivalis and T. forsythia.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.196-204
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• 2010

With the completion of genome sequencing of several organisms, attention has been focused to determine the function and functional network of proteins by proteome analysis. The recent techniques of proteomics have been advanced quickly so that the high-throughput and systematic analyses of cellular proteins are enabled in combination with bioinformatics tools. Furthermore, the development of proteomic techniques helps to elucidate the functions of proteins under stress or diseased condition, resulting in the discovery of biomarkers responsible for the biological stimuli. Ultimate goal of proteomics orients toward the entire proteome of life, subcellular localization, biochemical activities, and their regulation. Comprehensive analysis strategies of proteomics can be classified as three categories: (i) protein separation by 2-dimensional gel electrophoresis (2-DE) or liquid chromatography (LC), (ii) protein identification by either Edman sequencing or mass spectrometry (MS), and (iii) quanitation of proteome. Currently MS-based proteomics turns shiftly from qualitative proteome analysis by 2-DE or 2D-LC coupled with off-line matrix assisted laser desorption ionization (MALDI) and on-line electrospray ionization (ESI) MS, respectively, to quantitative proteome analysis. Some new techniques which include top-down mass spectrometry and tandem affinity purification have emerged. The in vitro quantitative proteomic techniques include differential gel electrophoresis with fluorescence dyes, protein-labeling tagging with isotope-coded affinity tag, and peptide-labeling tagging with isobaric tags for relative and absolute quantitation. In addition, stable isotope labeled amino acid can be in vivo labeled into live culture cells through metabolic incorporation. MS-based proteomics extends to detect the phosphopeptide mapping of biologically crucial protein known as one of post-translational modification. These complementary proteomic techniques contribute to not only the understanding of basic biological function but also the application to the applied sciences for industry.

• Applied Microscopy
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• v.37 no.1
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• pp.43-52
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• 2007

In order to observe the localization of excretory, purified and infected antigenic protein in the tissue of Trichinella spiralis larvae, immunogoldlabeling methodology using IgG and protein A-gold complex was implemented. T. spiralis larvae obtained from rat muscle were initially cultured in medium, and secreted excretory antigen was collected for 1 or 3 days. Purified antigenic protein was obtained from homogenized T. spiralis larvae. Rabbits were then immunized with 1 or 3 days secreted excretory protein and purified 45 kDa protein, and IgG was purified from collected serum. Serum, against infected antigen, collected from rat on 1 and 4 weeks after infection with T. spiralis larvae, and IgG was purified from collected serum. T. spiralis larvae were embedded in Lowicryl HM20 medium. Then they were finally treated with immunized IgG and protein A-gold complex (particle size; 15 nm) and observed under electron microscope. In T. spiralis larvae tissue, the tissue antigen reacted with rabbit IgC antigen Day 1 secreted excretory protein, infected antigenic protein and purified 45 kDa protein. But different distribution pattern of labeled gold particles were observed. When Day 1 secreted excretoy protein was used, gold particle labeling was observed specifically on the cuticle, basal layer, esophagus interstitial matrix (EIM) and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte of the worm. In a separate group of tissue, the antigen reacted with rabbit IgG against Day 3 secreted excretory protein. Labeled gold particles were specifically distributed on the surface layer of cuticle, EIM and ${\alpha}_0$ granules of stichocyte of the worm. In case of using infected antigenic protein, gold particle labeling was specifically distributed on the cuticle and EIM of the worm. When purifed 45 kDa protein was used gold particle labeling was specifically distributed on the cuticle, basal layer, EIM and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte of the worm. Therefore, excretory antigens appeared to originate from the cuticle and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte for the first day but the cuticle layer associated with globular proteins and ${\alpha}_0$ granules of stichocyte after 3 days and infected antigens appeared to originate from the cuticle for 1 and 4 weeks after infection. These results suggest that excretory and infection specific antigens are secreted into the cuticle, basal layer, EIM and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte and 45 kDa protein may be contained these specific antigens.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4337-4340
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• 2011

The vitamin D receptor binding peptide, VDRBP, was overexpressed as a fused form with the ubiquitin molecule in Rosetta(DE3)pLysS, a protein production strain of Escherichia coli harboring an induction controller plasmid. The fusion protein was bound to the immobilized metal ions, and the denaturation and renaturation of the fusion protein were performed as a part of the purification procedure. After the elution of the fusion protein, the peptide hormone was released from its fusion partner by using yeast ubiquitin hydrolase (YUH), and subsequently purified by reverse phase chromatography. The purity of the resulting peptide fragment was checked by MALDI-TOF mass and NMR spectroscopy. The final yields of the target peptide were around 5 and 2 mg per liter of LB and minimal media, respectively. The recombinant expression and purification of this peptide will enable structural and functional studies using multidimensional NMR spectroscopy and X-ray crystallography.