• Food Science of Animal Resources
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• v.21 no.3
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• pp.192-199
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• 2001

The objective of this study was to investigate the effects of hot- and cold-boning on sarcomere length, drip loss and protein solubility of post-rigor porcine longissimus muscle. A total of ten pigs(borrow, 100$\pm$5 kg) were randomly selected at a commercial plant and the carcasses were split in half after slaughter. The longissimus muscle of the left side was dissected and chilled at 0$^{\circ}C$ after trimming of subcutaneous fat whereas the right side carcasses were served for cold-boning after chilling for 24 hrs. The temperature, pH and sarcomere length of porcine longissimus muscle were measured at postmortem 1, 3, 6, 12 and 24 hours. Drip loss, cooking loss, Minolta L*a*b*, shear force and protein solubility were measured at postmortem 24 hrs. The pH of cold-boning samples was rapidly decreased whereas temperature and sarcomere length of hot-boning samples were rapidly decreased during 24 hrs of chilling. Hot-boning muscles showed significantly (P<0.05) higher pHu and shorter sarcomere compared with cold boning muscles because of cold shortening. However, there were no significant differences in drip loss, cooking loss and shear force value between hot- and cold boned samples. The samples of hot-boning showed lower Minolta L* value and higher sarcoplasmic protein solubility compared with cold boned samples. These results suggest that the pale color changing of porcine longissimus muscle could be inhibited by hot-boning due to rapid chilling of the muscle although sarcomere length could be shortened because of cold shortening. Also these results show that hot-boning of porcine carcass could have a high protein solubility without negative effects of drip loss or tenderness of porcine longissimus muscle.

• Molecules and Cells
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• v.39 no.10
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• pp.722-727
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• 2016

Cardiomyopathy is a major cause of death worldwide. Based on pathohistological abnormalities and clinical manifestation, cardiomyopathies are categorized into several groups: hypertrophic, dilated, restricted, arrhythmogenic right ventricular, and unclassified. Dilated cardiomyopathy, which is characterized by dilation of the left ventricle and systolic dysfunction, is the most severe and prevalent form of cardiomyopathy and usually requires heart transplantation. Its etiology remains unclear. Recent genetic studies of single gene mutations have provided significant insights into the complex processes of cardiac dysfunction. To date, over 40 genes have been demonstrated to contribute to dilated cardiomyopathy. With advances in genetic screening techniques, novel genes associated with this disease are continuously being identified. The respective gene products can be classified into several functional groups such as sarcomere proteins, structural proteins, ion channels, and nuclear envelope proteins. Nuclear envelope proteins are emerging as potential molecular targets in dilated cardiomyopathy. Because they are not directly associated with contractile force generation and transmission, the molecular pathways through which these proteins cause cardiac muscle disorder remain unclear. However, nuclear envelope proteins are involved in many essential cellular processes. Therefore, integrating apparently distinct cellular processes is of great interest in elucidating the etiology of dilated cardiomyopathy. In this mini review, we summarize the genetic factors associated with dilated cardiomyopathy and discuss their cellular functions.

• The Korean Journal of Food And Nutrition
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• v.2 no.2
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• pp.21-26
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• 1989

The morphological changes of fresh beef treated with ficin(0.1% : 2 hrs, 6 hrs)were examined with transmission electron microscope(TEM), the results obtained were as follows ; Connective tissue protein in fresh beef treated with ficin became gradually fragmentation and was occurred solubilization with time The length of sarcomere in myofibrillar protein was elongated, M-line became dim, and the 1-band of Z-line was broken and beck me fragmentation with time.

• Biomedical Science Letters
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• v.13 no.4
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• pp.263-272
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• 2007

Nebulin is a giant actin binding protein (600-900 kDa) which is specific to skeletal muscle. This protein is known to regulate thin filaments length in sarcomere as a molecular template. The C-terminus of nebulin is located in the Z-disc of muscle sarcomere and is bound to other proteins such like myopalladin, titin, archvillin, and desmin. The N-terminus of nebulin binds to tropomodulin at the pointed ends of the thin filaments. In recent research, nebulin not only found in brain but also expressed in heart, stomach, and liver. So, the roles of nebulin in non-muscle tissue have been studied. However, lack of information or studies on nebulin binding proteins and nebulin function in brain are available so far. Therefore, the current study have investigated a novel binding partner of Nebulin C-terminus by using yeast two-hybrid screening with human brain cDNA library. Nebulin C-terminus, containing simple repeats, serine rich and SH3 domain, interacts with osteonectin C-terminal region. The specific interaction of nebulin and osteonectin were confirmed in vitro by using GST pull-down assay and reconfirmed in vivo by using transfected COS-7 cells with EGFP-tagged nebulin and DsRed-tagged osteonectin. Consequently, this study identified SH3 domain in nebulin C-terminus specifically binds to extracellular Ca-binding (EeC domain in osteonectin. Also, nebulin C-terminus fusion protein colocalized with osteonectin EC domain fusion protein in transfected COS-7 cells. The current study found the interaction between nebulin and osteonectin in human brain for the first time and suggested the nebulin in brain may be associated with osteonectin, as a regulator of cell cycle progression and mitosis.

• Proceedings of the Culinary Society of Korean Academy Conference
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• 2005.04a
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• pp.19-42
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• 2005

This study was conducted to investigate the proteolytic properties of Sarcodon aspratus on meat proteins. The analytical condition for the measurement of enzyme activity was determined and the effect of Sarcodon aspratus on beef protein and its fractions were determined by SDS-PAGE and spectrophotometric method, respectively. Optimum temperature and pH of Sarcodon aspratus was $73-78^{\circ}C$,pH 8, respectively. However, the enzyme tended to be denatured at $50^{\circ}C$ for 10min incubation. Proteolytic activity of Sarcodon aspratus was higher than those of kiwi and pear by 66 and 990 times by dry weight, respectively. It was appeared that proteolytic activity of Sarcodon aspratus toward beef protein by SDS-PAGE was prominent when compared to those of kiwi and bromelain. Furthermore, Sarcodon aspratus showed highest proteolytic activity toward all the beef protein fractions, which was followed by collagenase and bovine protease. Transmission electron microscopy showed the muscle fiber started to be degraded when treated with Sarcodon aspratus(1,000 unit) for 10min at $25^{\circ}C$. No distinct sarcomere, A-band, and z-line was observed when treated with Sarcodon aspratus for 60min at same condition.

• Culinary science and hospitality research
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• v.11 no.2
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• pp.110-124
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• 2005

This study was conducted to investigate the proteolytic properties of Sarcodon aspratus on meat proteins. The analytical condition for the measurement of enzyme activity was determined and the effect of Sarcodon aspratus on beef protein and its fractions were determined by SDS-PAGE and the spectrophotometric method respectively. Optimum temperature and pH of Sarcodon aspratus were $73~78^{\circ}C$ and pH 8 respectively. However, enzyme tended to be denatured at $50^{\circ}C$ for 10 min incubation. Proteolytic activity of Sarcodon aspratus was higher than of kiwi and pear 66 and 990 times by dry weight respectively. It appeared that proteolytic activity of Sarcodon aspratus toward beef protein by SDS-PAGE was prominent when compared to that of kiwi and bromelain. Furthermore, Sarcodon aspratus showed the highest proteolytic activity toward all the beef protein fractions, which was followed by collagenase and bovine protease. Transmission electron microscopy showed the muscle fiber started to be degraded when treated with Sarcodon aspratus(1,000 unit) for 10min at $25^{\circ}C$. No distinct sarcomere, A-band, or z-line was observed when treated with Sarcodon aspratus for 60min at the same condition.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2000.06a
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• pp.123-123
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• 2000

• Biomedical Science Letters
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• v.13 no.1
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• pp.1-10
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• 2007

Nebulin, a giant modular protein from muscle, is thought to act as molecular ruler in sarcomere assembly. In skeletal muscle, the C-terminal ${\sim}50 kDa$ region of nebulin extends into the Z-line lattice. The most recent studies implicated highlighting its extensive isoform diversity and exciting reports revealed its expression in cardiac and non-muscle tissues containing brain. Also these novel findings are indicating that nebulin is actually a multifunctional filament system, perhaps playing roles in signal transduction, contractile regulation, and myofibril force generation, as well as other not yet defined functions. However the binding protein of nebulin and function in brain is still unknown. A novel binding partner of nebulin C-terminal region was identified by screening a human brain cDNA library using yeast two-hybrid system. Nebulin C-terminus binding protein 51 (NCBP51) was contained a RING-finger domain and identified a new isoform of RING finger protein 125 (RNF125). The interaction was confirmed using the GST pull-down assay. NCBP51 belongs to a family of the RING finger proteins and its function remains to be identified in brain. The role of nebulin and NCBP51 will be studied by loss-of-function using siRNA technique in brain.

• Biomedical Science Letters
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• v.7 no.4
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• pp.167-172
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• 2001

Nebulin is an approximately 700 kDa filamentous protein in vertebrate skeletal muscle. It binds to the Z line and also binds side-by-side to the entire thin actin filament in a sarcomere. The correlation of nebulin size with thin filament length have led to the suggestion that nebulin acts as a molecular ruler for the length of thin filaments. The C-terminal part of human nebulin is anchored in the sarcomeric Z-disk and contains an SH3 domain. SH3 domains have been identified in an ever-increasing number of proteins important for a wide range of cellular processes, from signal transduction to cytoskeleton assembly and membrane localization. However, the exact physiological role of SH3 domains remains, in many cases, unclear. To explore the role of nebulin SH3 in the cytoskeletal rearrangement that accompanies myoblast differentiation, we transfected sense and antisense nebulin SH3 domain fused to enhanced green fluorescent protein in myoblast. Cells expressing nebulin SH3 fragment showed decrease of cell-cell adhesion, and cells transfected with antisense nebulin SH3 gene showed a rounded cell morphology and loss of cell-matrix adhesion. No alteration in cell shape and differentiation were observed in control cells expressing enhanced green fluorescent protein. Perturbation of nebulin altered the cell shape and disrupted cell adhesion in myoblast, demonstrating that nebulin can affect cytoskeleton rearrangement.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.859-866
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• 2015

To determine chemical components and meat quality traits related to palatability of 10 primal cuts, 25 Hanwoo carcasses were selected from 5 carcasses × 5 quality grades and used to obtain proximate data and meat quality characteristics. Significant differences (p<0.05) in chemical component and meat quality were found among the 10 primal cuts. The highest fat content was found in the kalbi, followed by dungsim, yangjee, chaekeut, ansim, abdari, suldo, moksim, udun, and satae. Protein and moisture contents in the 10 primal cuts were in reverse order of fat content. Moksim had the highest drip loss % and cooking loss % than all other primal cuts while kalbi showed the lowest (p<0.05) percentage of drip and cooking loss. Ansim had the longest sarcomere length but the lowest shear force values than all other cuts (p<0.05). The highest (p<0.05) score for overall acceptability was observed in ansim. Moksim, udun, abdari, and satae were rated the lowest (p<0.05) in overall acceptability among the 10 primal cuts from Hanwoo carcasses. In conclusion, ansim, dungsim, chaekeut, and kalbi had the highest overall acceptability due to their higher fat contents and lower shear force values.