• 대한약리학회지
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• 제8권2호
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• pp.55-61
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• 1972

Superprecipitation of actomyosin has been considered to be an in vitro model of the muscle contraction. The superprecipitation and ATPase activity (which supplies the energy for contraction) are influenced by several factors which are the large amount of changes in ionic strength, Mg and ATP concentrations. But those behaviors are found to be promptly influenced by the change in a small range of calcium concentration which can be controlled by the cellular function of muscle physiologically only in the presence of the modullatory proteins, tropomyosin and troponin. In order to elucidate the precise roles of calcium in the muscle contraction and relaxation, the effects of calcium on the actin- myosin interaction was observed in the presence of tropomyosin and troponin using the superprecipitation system. The results are summarized as follows: 1. EGTA (glycol ether diaminetetraacetic acid)prolonged the initiation of the superprecipitation of natural actomyosin. 2. Superprecipitation curve was declined by adding EGTA at the time when tile curve reached the half- maximum. The degree of declining was proportional to the amount of EGTA added. Especially, upon adding 0.25 mM EGTA the curve was lowered to the level before the protein superprecipitated. But addition of EGTA did not affect the curve after attaining the maximum. 3. Superprecipitation of Perry myosin B was not affected by EGTA added both before and during the course of the reaction. 4. Tropomyosin did not change the response of Perry myosin B to EGTA added at any time of the reaction. 5. Troponin also did not change the response of Perry myosin B to EGTA. 6. Both tropomyosin and troponin together rendered the Perry myosin B to obtain the same response as natural actomyosin to EGTA. 7. It was concluded that actin-myosin interaction was influenced by the minute change of calcium concentration only in the presence of both tropomyosin and troponin. We could reproduce the contraction and relaxation of the muscle in vitro under the presence of ATP by changing the calcium concentration.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1384-1389
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• 2003

In order to clarify one of the biological functions of pork, we investigated whether a peptic hydrolysate of denatured porcine crude myosin showed inhibitory activity against angiotensin I-converting enzyme (ACE), which contributed to hypertension. Our results indicated that this hydrolysate showed relatively strong activity, and we therefore attempted to separate the involved peptides, which were considered to be active substances. To isolate these active peptides, the hydrolysate was separated using a solidphase separation, gel filtration high-performance liquid chromatography (HPLC), and two kinds of reverse phase HPLC. In each stage of separation, many fractions were detected, almost all of which showed ACE inhibitory activity. Thus, we suggested that the activity of the hydrolysate as a whole was a result of the activities of the many individual peptides. Six peaks were distinguished, with yields from 34 to 596 ppm of original crude myosin. In addition to the six peaks, many other active fractions were found throughout the separation steps, strongly suggesting that whole porcine crude myosin itself had ACE inhibitory activity. Moreover, pork as food was considered to function as an ACE inhibitory material in vivo, because pork proteins consist primarily of crude myosin, which included almost all the myofibrillar structural proteins.

• 한국식품과학회지
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• 제19권2호
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• pp.89-96
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• 1987

방어와 갈색띠 매물고둥에서 myosin과 paramyosin 을 추출하고, 이들 단백질의 가열중에 일어나는 변성기구를 아미노산 잔기와 SH기의 변화 및 단백질간의 상호작용 등을 측정하므로서 분석하였다. 각 단백질을 이루는 구성아미노산의 측쇄중 소수성 잔기의 유리정도는 가열온도 $65^{\circ}C$까지는 증가하였으나, 그 이상의 가열온도에서는 감소하는 경향을 보였다. 유리 소수성 잔기가 증가하여 감에 따라, 단백질간 상호작용도 활발하여 갔으며, 소수성 잔기의 유리정도가 감소하는 가열온도$65^{\circ}C$부터는 단백질의 응집이 일어나기 시작 하였다. 단백질간의 상호작용을 탁도로써 분석하여 Arrhenius식으로 해석한 결과, 방어 myosin은 3단계이상의 변성과정으로 구분할 수 있었으며, 갈색띠 매물고둥 paramyos은 2단계의 변성과정으로 구분할 수 있었다. 이들 두 단백질 소수성, 용해도, 유리 SH기의 수 및 단백질간의 상호작용 등은 온도함수와 밀접한 상관관계를 보였다.

• 대한약리학회:학술대회논문집
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• 대한약리학회 2006년도 The 6th Congress of the Federation of Asian and Oceanian Physiological Societies
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• pp.113.1-113.1
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• 2006

• 한국식품과학회지
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• 제22권6호
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• pp.640-645
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• 1990

우육에 7.5%의 당을 첨가하고 $121^{\circ}C$에서 가열처리하여 근원섬유단백질의 전기영동 pattern 변화를 알아보았다. 당을 첨가하지 않은 경우 가열처리시간이 길어짐에 따라 myosin heavy chain(MHC) 등의 분자량이 큰 단백질의 band강도는 크게 약화되었지만 actin 등의 분자량이 작은 단백질은 거의 변화가 없었으며 당을 첨가한 처리구에서는 가열처리에 의하여 MHC 등의 band강도가 더욱 약화되었는데 특히 glucose 첨가시 15분간 가열처리구에서는 actin band의 강도도 크게 약해졌다. 시료에 peptidase를 작용시킨 후 추출한 단백질의 전기영동 pattern은 거의 변화가 없었으며 chymotrypsin을 작용시켰을 때 근원섬유를 구성하는 단백질들이 소화된 것을 보여주었으나 갈변반응이 심하게 발생하였던 glucose 첨가구에서는 myosin분자 등의 중합체가 나타났다 Trypsin을 작용시켰을 때 전체적으로 chymotrypsin의 경우보다 더욱 소화된 것을 보여주면서 glucose 첨가구에서는 myosin분자 등의 중합체가 더욱 강하게 나타났으며 peptidase chymotrypsin, trypsin을 동시에 작용시켜도 glucose 첨가구에서는 myosin 분자 등의 중합체가 소화되지 못하며 그 강도도 fructose 첨가구의 것보다 강한 것을 보여 주었다.

• 동의생리병리학회지
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• 제16권5호
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• pp.1060-1065
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• 2002

LC20 phosphorylation and PKC α play an important role in modulation of contractile activity of smooth muscle. Besides, myosin phosphatase is also related with smooth muscle contraction in signaling pathways. We previously demonstrated that Crataegi Fructus inhibited phenylephrine-induced contraction and which might be implicated in nitrite formation(Son et al., 2002). In this study, we investigated the effects of butanol fraction of Crataegi Fructus(BFFC) on the localization of α-protein kinease C(PKC α) and myosin phosphatase subnits(MPs) in freshly isolated single ferret potal vein cells, and phosphorylation of LC20 during phenylephrine stimulation. In PKC α and MPs localization, BFFC blocked its translocation from the cytosol to the cell membrane by treatment of phenylephrine. BFFC have also dephosphorylated LC20 phosphorylation by phenylephrine stimulation under basal level, but no significant. These results indicate that the relaxation effect of BFFC is associated with inhibition of PKC α activation and MPs dissociation, and thus myosin phosphatase activity may be increased.

• Preventive Nutrition and Food Science
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• 제6권2호
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• pp.91-95
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• 2001

Competitive indirect enzyme linked immunosorbent assay (Ci-ELISA) was used to obtain the preliminary data for the detection of irradiated beef. Ci-ELISA was individually formatted with polyclonal antibodies produced from 2 kinds of bovine proteins, myosin and bovine serum albumin (BSA). Beef round, loin and tender loin were vacuum-packaged and subdivided into 3 groups of 1) irradiation; 2) irradiation and chilled at 4$^{\circ}C$ for 7 day; 3) irradiation and frozen at 2$0^{\circ}C$ for 2 months to observe the changes under different storage and/or distribution conditions. Irradiation was performed at 3, 5 and 7 kGy. Protein solutions prepared from the sample were tested by formatted Ci-ELISA. Detected concentrations of myosin and BSA decreased with the increased irradiation dose in all samples with different reduction rates. Myosin was more susceptible to freezing than BSA. Samples irradiated at 5 kGy or above could be differentiated from non-irradiated ones by Ci-ELISA. These results indicate that immunological assay can be used as a detection method for irradiated beef.

• 한국응용과학기술학회지
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• 제21권2호
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• pp.182-189
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• 2004

On contraction of the muscles, marked changes in X-ray reflections are observed, suggesting that conformational changes of contractile molecules and the movement of myosin heads during muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The muscles were stimulated by five successive stimuli at an interval of 80 ms started while the tension was still being exerted by the muscles. The intensity of $I_{11}$, $I_{10}$, $143{\AA}$ and $215{\AA}$ reflection measured with 5ms time resolution and is recorded in isometric tension. The peak height of $I_{11}$ and $143{\AA}$ intensity is changed after the onset of a stimulation $I_i$, and the length of twitch is shortened by successive twitches in the case of stimulation $T_i$. On the other hand, the peak height of In and $215{\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak height without appreciable recovery during the contraction term. In the case of successive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.1065-1080
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• 2023

The solubility and structure of myosin and the properties of pork gel with NaCl, KCl, CaCl₂, and MgCl₂ were investigated. Myofibrillar proteins (MPs) with phosphate were more solubilized with NaCl than with KCl (p < 0.05). CaCl₂ and MgCl₂ showed lower MP solubilities than those of NaCl and KCl (p < 0.05). The α-helix content of myosin was lower in KCl, CaCl₂, and MgCl₂ than in NaCl (p < 0.05). The pH of pork batter decreased in the order of KCl, NaCl, MgCl₂, and CaCl₂ (p < 0.05). The cooking yield of the pork gel manufactured with monovalent salts was higher than that of the pork gel manufactured with divalent salts (p < 0.05). The pork gel manufactured with KCl and MgCl₂ showed lower hardness than that of the pork gel manufactured with NaCl. The solubility and structure of myosin were different with the different chloride salts and those led the different quality properties of pork gel. Therefore, the results of this study can be helpful for understanding the quality properties of low-slat meat products manufactured by replacing sodium chloride with different chloride salts.

• BMB Reports
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• 제48권1호
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• pp.48-53
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• 2015

Oxidized LDL (oxLDL) performs critical roles in atherosclerosis by inducing macrophage foam cell formation and promoting inflammation. There have been reports showing that oxLDL modulates macrophage cytoskeletal functions for oxLDL uptake and trapping, however, the precise mechanism has not been clearly elucidated. Our study examined the effect of oxLDL on non-muscle myosin heavy chain IIA (MHC-IIA) in macrophages. We demonstrated that oxLDL induces phosphorylation of MHC-IIA (Ser1917) in peritoneal macrophages from wild-type mice and THP-1, a human monocytic cell line, but not in macrophages deficient for CD36, a scavenger receptor for oxLDL. Protein kinase C (PKC) inhibitor-treated macrophages did not undergo the oxLDL-induced MHC-IIA phosphorylation. Our immunoprecipitation revealed that oxLDL increased physical association between PKC and MHC-IIA, supporting the role of PKC in this process. We conclude that oxLDL via CD36 induces PKC-mediated MHC-IIA (Ser1917) phosphorylation and this may affect oxLDL-induced functions of macrophages involved in atherosclerosis.