• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1496-1502
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• 2006

Skeletal muscle contains slow and fast twitch fibers. These skeletal muscle fibers express type I and type II myosin, respectively, and these myosin isoenzymes have different ATPase activity. The aim of this study was to investigate protein profiles of bovine skeletal muscles by proteomic analysis. Fifty seven spots of distinct proteins were excised and characterized. The expression of sixteen spots was differed in longissimus dorsi muscle with a minimal 2-fold change compared to biceps femoris muscle. The majority of differentially expressed proteins belonged to metabolic regulation-related proteins such as glyceraldehyde 3-phosphate dehydrogenase, triosephosphate isomerase and carbonic anhydrase 3. The real time-PCR assay confirmed an increase or induction of specific genes: RGS12TS isoform, GAPDH, triosephosphate isomerase and carbonic anhydrase. These results suggest that the expression of metabolic proteins is under a specific control system in different bovine skeletal muscle. These observations could have significant implications for understanding the physiological regulation of bovine skeletal muscles.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.151-159
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• 1997

In order to compare and examine the general characteristics of myofibrillar proteins which is an important protein source as a food resource and relates directly with muscle contraction, we have extracted the myofibrillar proteins from squid and clam. The ionic strength of myofibrillar proteins connected with Ca-ATPase activity, Mg-ATPase activity and EDTA-ATPase activity showed distinct differences between squid and clam. In the activity-pH curve, actomyosin of the clam had a weak biphasic response. In the low concentration of dioxane, myofibrillar proteins of the squid showed a sudden decrease in activity but myofibrillar proteins of the clam showed in increase in activity. Ethanol and metanol in low concentration caused myosin and HMM from the squid and clam to increase their activities. If we cause modification by NEM, under 10-6M concentration, the activity was increased but above 10-5M concentration, there was a sudden decrease in activity.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1083-1088
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• 2012

The breeding value of marbling score in skeletal muscle is an important factor for evaluating beef quality. In the present study, we investigated proteins associated with the breeding value of the marbling score for bovine sirloin to select potential biomarkers to improve meat quality through comparative proteomic analysis. Proteins isolated from muscle were separated by two-dimensional gel electrophoresis. After analyzing images of the stained gel, seven protein spots for the high marbling score group were identified corresponding to changes in expression that were at least two-fold compared to the low marbling score group. Four spots with increased intensities in the high marbling score group were identified as phosphoglycerate kinase 1, triosephophate isomerase, acidic ribosomal phosphoprotein PO, and capping protein (actin filament) Z-line alpha 2. Spots with decreased intensities in the high marbling score group compared to the low score group were identified as 14-3-3 epsilon, carbonic anhydrase II, and myosin light chain 1. Expression of myosin light chain 1 and carbonic anhydrase 2 was confirmed by Western blotting. Taken together, these data could help improve the economic performance of cattle and provide useful information about the underlying the function of bovine skeletal muscle.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.1
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• pp.102-108
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• 2006

Microbial transglutaminase (MTGase) was investigated to determine whether it was an effective binding agent for the processing of low-quality pork loins. MTGase especially promoted the coagulation of myosin heavy chain (MHC). However, the effect of MTGase on MHC from low-quality meat was less than that from the normal meat when the reaction time was not enough. The breaking strength of the heat-induced gel made of myosin B from low-quality meat with MTGase was lower than that of normal meat. Sausage made with low-quality meat with MTGase did not exhibit improved hardness, as compared to that made with normal meat. Results of this study indicated that use of low-quality meat in the manufacture of sausage was feasible to get textural property equal to that of normal meat sausage, when a half or more of the raw material was normal meat and MTGase was used in the sausage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.315-320
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• 2008

This study investigated the signaling mechanisms contributed to the vasodilatory effects of HMC05, a herbal prescription. HMC05 acted in an endothelium-independent manner. To elucidate the fundamental mechanisms of its vascular actions, we focused on the signaling molecules involved in actin-myosin filament regulation including 20 kDa myosin light chains (LC20), Rho-associated kinase (ROCK), PKC, JNK and extracellular signal-regulated protein kinase (ERK) in the endothelium-denuded thoracic aorta or isolated smooth muscle cells (SMCs). It lowered the phosphorylation level of LC20 and showed that ROCK, ERK, JNK and $PKC{\alpha}$ pathways played important roles in the effects, as confirmed by the observations with a specific inhibition or activation, and with the activity and the subcellular localization of these molecules. In particular, HMC05 dramatically inhibited the activity of ERK and the downstream signaling of ROCK. It also changed the subcellular localization of the phophorylated $PKC{\alpha}$ as well as the amount of phosphorylation. Taken together, these data indicate that the vascular relaxation effects of HMC05 are attributed to the regulation of these signaling mechanisms.

• The Korean Journal of Zoology
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• v.24 no.4
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• pp.173-188
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• 1981

근세포의 분화에 있어서의 근특이 단백질의 합성 순서를 구명하기 위하여 계배 근세포를 2$\\sim$9일간 배양하면서 단백질합성야상을 SDS-polyacrylamide 겔전기 영동법, 등전점초점2차원 전기영동법 및 방사자기법으로 분석하였다. Actin은 분화의 초기부터 활발히 합성되어 그 양이 다량으로 축적되나, myosin은 배양 3일째부터 대량 합성되기 시작하였다. Myosin의 대량합성시기는 배양 근원세포가 융합을 활발히 일으키는 시기와 거의 같았다. Myoglobin은 분화초기부터 서서히 합성축적되기 시작하여 배양 5일에서 최대치에 달하였다. Creatine phosphokinase는 배양 3일만에, 그리고 glyceraldehyde dehydrogenase는 6일만에 전기영동상에 검출되었다. Tropomyosin $\\alpha$와 $\\beta$, 그리고 troponin C는 분화초기부터 비교적 다량 합성되고 있었다. 젖산탈수소효소의 활성은 배양 2$\\sim$5일 사이에서 급격히 증가하고 이후 거의 변화가 없었다. 이 효소의 동위효소 조성은 초기 근원세포에서는 $H_4$와 $H_3M$형이 많으나 분화가 진행됨에 따라 $HM_3 와 M_4$형이 서서히 출현하였다. 그리고 배양 5일만에 5종의 동위효소가 모두 검출되었다.

• Korea Journal of Cosmetic Science
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• v.1 no.1
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• pp.31-43
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• 2019

Melanosomes are specific melanin-containing intracellular organelles of epidermal melanocytes. In epidermal melanocytes, there are three kinds of key player proteins. Rab27a, melanophilin or Slac2-a and Myosin 5a form a tripartite complex connects the melanosome. Mature melanosomes make movements through the tripartite protein complex along actin filaments.In this study, we found that the haplamine (6-Methoxyflindersine) induced melanosome aggregation around the nucleus in epidermal melanocyte. In an attempt to elucidate the inhibitory effect of haplamine on melanosome transport, effect of haplamineon the expression level of Rab27a, melanophilin and Myosin 5a was measured. The results indicated that haplamine up to 5��M effectively suppressed mRNA and protein expression level of melanophilin.To determine the upstream regulator of melanophilin regulated by haplamine, we checked the level of MITF, c-JUN and USF1. Those are possible transcription factor of melanophilin. Among them,treatment of USF1 siRNA decreased mRNA and protein expression level of USF1 as well as melanophilin. Also, treatment of haplamine decreased mRNA and protein expression level of melanophilin as well as USF1 in a dose-dependent manner. Consequently, we found the inhibitory effect of haplamine on melanosome transport in melan-a melanocyte. Treatment of haplamine reduced melanophilin expression level which is a key protein of melanosome transport. We identified that USF1 could be a major transcription factor of melanophilin regulated by haplamine.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.1
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• pp.33-39
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• 2002

It has been suggested that $Ca^{2+}$ sensitization mechanisms might contribute to myogenic tone, however, specific mechanisms have not yet been fully identified. Therefore, we investigated the role of protein kinase C (PKC)- or RhoA-induced $Ca^{2+}$ sensitization in myogenic tone of the rabbit basilar vessel. Myogenic tone was developed by stretch of rabbit basilar artery. Fura-2 $Ca^{2+}$ signals, contractile responses, PKC immunoblots, translocation of PKC and RhoA, and phosphorylation of myosin light chains were measured. Stretch of the resting vessel evoked a myogenic contraction and an increase in the intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ only in the presence of extracellular $Ca^{2+}$. Stretch evoked greater contraction than high $K^+$ at a given $[Ca^{2+}]_i.$ The stretch-induced increase in $[Ca^{2+}]_i$ and contractile force were inhibited by treatment of the tissue with nifedipine, a blocker of voltage-dependent $Ca^{2+}$ channel, but not with gadolinium, a blocker of stretch-activated cation channels. The PKC inhibitors, H-7 and calphostin C, and a RhoA-activated protein kinase (ROK) inhibitor, Y-27632, inhibited the stretch-induced myogenic tone without changing $[Ca^{2+}]_i.$ Immunoblotting using isoform-specific antibodies showed the presence of $PKC_{\alpha}$ and $PKC_{\varepsilon}$ in the rabbit basilar artery. $PKC_{\alpha},$ but not $PKC_{\varepsilon},$ and RhoA were translocated from the cytosol to the cell membrane by stretch. Phosphorylation of the myosin light chains was increased by stretch and the increased phosphorylation was blocked by treatment of the tissue with H-7 and Y-27632, respectively. Our results are consistent with important roles for PKC and RhoA in the generation of myogenic tone. Furthermore, enhanced phosphorylation of the myosin light chains by activation of $PKC_{\alpha}$ and/or RhoA may be key mechanisms for the $Ca^{2+}$ sensitization associated with myogenic tone in basilar vessels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.100-108
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• 1986

This study was carried out in order to investigate protein cross-linking in freeze-dried meat of flounder (Limanda herzensteini). Changes in solubility or extractability of proteins and electrophoretic patterns of the extracted proteins were determined to monitor the cross-linking during the storage of freeze-dried meat. Development of nonenzymatic browning and the loss of in vitro protein digestibilily were also measured to assess their influences on the changes of functional and nutritional properties of proteins. In addition, the effects of lysine added, and removal of fat and water extractives were also mentioned. The extractability of protein decreased upon storage time and temperature, and the loss of solubility of myosin was evident. In case of the samples stored at $5^{\circ}C$ for 150 days, the extractability of protein decreased $26.4\%$, while that of the samples stored at $20^{\circ}C$ for 60 days decreased about $39.7\%$. And it was noted that the loss of solubility of myosin was $68.3\%$ and $98.1%$ for the same storage conditions, respectively. It was noteworthy that the samples treated with $L-lysine{\cdot}HCl$ seemed to prevent more or less the loss of protein solubility, in that, even stored at $20^{\circ}C$ for 120 days, revealed only $57.03\%$ decrease. The nonenzymatic browning was proceeded with the increase of storage temperature, especially, in the samples treated with glucose. This suggests that the decrease in extractibility of myosin was accompanied by the extent of browning. But the browning was retarded in defatted samples. The in vitro apparent protein digestibility was also higher in the samples defatted or water extracted. It was suggested from these results that changes in properties of proteins in freeze dried fish meat were led by the protein cross-linking which was attributed to Maillard type of reactions and protein-lipid interactions.

• Toxicological Research
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• v.25 no.4
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• pp.181-188
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• 2009

Uncontrolled cell growth and increased cell proliferation are major features of cancer that are dependent on the stable structure and dynamics of the cytoskeleton. Since stable cytoskeleton structure and dynamics are partly regulated by myosin light chain kinase (MLCK), many current studies focused on MLCK inhibition as a chemotherapeutic target. As a potent and selective MLCK inhibitor, ML-7 [1-(5-iodonaphthalene-1-sulfonyl)-1 H-hexahydro-1,4-diazapine hydrochloride] is a promising candidate for an anticancer agent, which would induce apoptosis as well as prevents invasion and metastasis in certain types of cancer cells. This study assessed cytotoxic effects of ML-7 against HL-60 cells and therapeutic efficacy of ML-7 as a potential antileukemia agent. Trypan-blue exclusion assays showed dose- and time- dependent decreases in ML-7 treated HL-60 cells (p<0.05). Comet assays revealed a significant increase in DNA damage in HL-60 cells after treatment with $40{\mu}M$ ML-7 for 2h. Sub-G1 fractions, analyzed by flow cytometry increased in a dose-dependent manner, suggesting that ML-7 can induce apoptotic cell death in HL-60 cells. ML-7 was selectively cytotoxic towards HL-60 cells; not affecting normal human lymphocytes. That selective effect makes it a promising potential anti-leukemia agent. In addition, anticancer efficacy of ML-7 in combination with flavonoids (genistein or quercetin) or anticancer drugs (cisplatin or Ara-C) against HL-60 cells was assessed. Combination of ML-7 with flavonoids increased the anti-cancer effect of ML-7 to a greater extent than combination with the anticancer drugs. This implies that ML-7 in combination with flavonoids could increase the efficacy of anticancer treatment, while avoiding side effects cansed by conventional anticancer drug-containing combination chemotherapy.