• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.181-186
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• 1986

Myosin were prepared from red muscle and white muscle, and their ATPase activities were compared. Ca-ATPase activity of bovine myosin from red muscle was higher than that of myosin from white muscle, while Ca-ATPase activity of chicken myosin from red muscle differed hardly from that of myosin from whitemuscle. Atso EDTA-ATPase activity of bovine red muscle myosin was higher than that of white muscle myosin ,although EDTA-ATPase activity of chicken myosin from red muscle differed hardly from that of white muscle myosin. When myosins were treated with trypsin, bovine myosin from white muscle was hydrolysed moreeasily than red muscle myosin was. Chicken myosin from red muscle , however, was hydrolysed by trypsin more easily than white muscle myosin was.

• Food Science of Animal Resources
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• v.36 no.2
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• pp.254-261
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• 2016

The purpose of this study was to analyze oxidized methionines in the myosin isoforms of porcine longissimus thoracis, psoas major, and semimembranosus muscles by liquid chromatography (LC) and mass spectrometry (MS). A total of 836 queries matched to four myosin isoforms (myosin-1, -2, -4, and -7) were analyzed and each myosin isoform was identified by its unique peptides (7.3-13.3). Forty-four peptides were observed from all three muscles. Seventeen peptides were unique to the myosin isoform and the others were common peptides expressed in two or more myosin isoforms. Five were identified as oxidized peptides with one or two methionine sulfoxides with 16 amu of mass modification. Methionines on residues 215 (215), 438 (438), 853 (851), 856 (854), 1071 (1069), and 1106 (1104) of myosin-1 (myosin-4) were oxidized by the addition of oxygen. Myosin-2 had two oxidized methionines on residues 215 and 438. No queries matched to myosin-7 were observed as oxidized peptides. LC-MS/MS allows analysis of the oxidation of specific amino acids on specific residue sites, as well as in specific proteins in the food system.

• Applied Microscopy
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• v.48 no.2
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• pp.33-42
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• 2018

Myosin X is one of myosin superfamily members having unique cellular functions on cytoskeletal reorganization. One of the most important cellular functions of myosin X is to facilitate the formation of membrane protrusions. Since membrane protrusions are important factors for diverse cellular motile processes including cell migration, cell invasion, path-finding of the cells, intercellular communications and so on, it has been thought that myosin X plays an important role in various processes that involve cytoskeletal reorganization including cancer progression and development of neuronal diseases. Recent studies have revealed that the unique cellular function of myosin X is closely correlated with its unique structural characteristics and motor properties. Moreover, it is found that the molecular and cellular activities of myosin X are controlled by its specific binding partner. Since recent studies have revealed the presence of various specific binding partners of myosin X, it is anticipated that the structural, biochemical and cell biological understanding of the binding partner dependent regulation of myosin X function can uncover the role of myosin X in diverse cell biological processes and diseases.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.155-164
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• 1995

The location of actin and myosin of the several stages of Cwptosporinium parvum was observed. The tissue antigen of C. pcruum was prepared through immunosuppression of IgG mice with Depomedrol . The thin sectioned specimens, which were incubated with the IgG fraction of the rabbit polyclonal antibodies raised against chicken back muscle actin and bovine uterus myosin, were treated with 10 nm gold-conjugated goat anti-rabbit IgG, Electrodense particles were located mainly on the pellicles of all observed developmental stages of the parasites. The number of actin gold particles in the cytoplasm increased when the parasite was dividing actively as in case of meronts. Especially in macrogametocytes, a lot of actin and myosin particles were synthesized and storaged as amilopectin-like bodies. There were many actin gold particles along the microspikes of cytoplasmic membranes in various developmental stages. The actin and myosin observed in this study may play important roles to control the shape of the parasites and movement of cytoplasmic membranes as cvtoskeletal proteins.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.347-352
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• 1993

N-ethylmaleimide at low concentrations is known to interact specifically with 2 sulfhydryl residues in myosin heavy chain. Calpain, a Ca$^2$+-dependent neutral protease isolated from chick skeletal muscle, was found to preferentially degrade the alkylated protein but much less significantly the unmodified protein. Exposure of myosin to KMnO$_4$, which is also known to interact with sulthydryl groups, also caused the rapid degradation of the myosin heavy chain. Furthermore, treatment of each agent with increasing concentrations results in a greater loss of the myosin ATPase activity, indicating that the modification occurred at the reactive site sulfhydryl residues. These results suggest that the covalent modification at the reactive site salfhydryl residues in the myosin heavy chain may mark the protein for degradation by intracellular proteases such as calpain.

• Journal of Life Science
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• v.9 no.6
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• pp.646-652
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• 1999

The effect of temperature on the structure change of the SH of myosin head have been investigated with improved resolution by x-ray diffraction using synchrotron radiation. The movement of myosin head and conformational change of contractile molecules were occurred in the muscle contraction. IASL (iodo acetamide) and MSL (maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. The temperature effect on the structure change was great at the UL in the equatorial reflection. But those of IASL and MSL were minor. Equatorial reflection (10, 11) change inferred that myosin head was moved to the vicinity of actin filament by temperature change (from $25^{\circ}C$ to $0^{\circ}C$) at UL, but spin level was not changed. The intensity change of 143 $\AA$ and 72 $\AA$ could offer information of the mass profection of population of myosin heads along the filament axis. The slope of intensity profile of the mass profection of 143$\AA$ and reflection of MSL is appeared sharply and those of UL and IASL were not changed. The decrease of MSL actin reflection at 51 $\AA$ and 59 $\AA$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure. From these results, we could conclude that IASL and MSL were spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• Journal of Life Science
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• v.8 no.6
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• pp.681-686
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• 1998

IASL(iodo acetamide) and MSL(maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. Equatorial reflection(10,11) change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of 143 $\AA$ and 72 $\AA$ could offer infor-mation of the mass projection of population of myosin heads along the filament axis. The slope of intensity profile of the mass projection of 143 $\AA$ and reflection of IASL is appeared and that of MSL is appeared sharply. The dec-rease of 215 $\AA$ reflection intensity the periodical characteristic of 143 $\AA$ reflection by spin label. The raise of MSL actin reflection at 51 $\AA$ and 59 $\AA$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we could conclude that LASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• Journal of Life Science
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• v.25 no.5
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• pp.585-593
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• 2015

Stress fiber (SF) alteration is mediated by cellular receptors, which, upon interaction with the extracellular counterpart, signal to the actin cytoskeleton for remodeling. This association is mediated by a variety of scaffold and signaling factors, which control the mechanical and signaling activities of the interaction site. The heterotrimeric transmembrane lymphotoxin α1β2 (LTα1β2), a member of the tumor necrosis factor (TNF) family of cytokines, including soluble homotrimeric lymphotoxin (LT α), plays an important role in lymphoid tissue architecture. Ligation between LTα1β2 and the lymphotoxin β receptor (LTβR) activates signal-cascade in fibroblastic reticular cells (FRCs). We found LTβR stimulation using an agonistic anti-LTβR antibody alone or combined with LTα or TNFα induced changes in the actin and plasticity of cells. To clarify the involvement of myosin underlying the alteration, we analyzed the effect of myosin light chain kinase (MLCK) with an MLCK inhibitor (ML7), the phosphorylation level of myosin light chains (MLC), and the level of phospho-myosin phosphatase target subunit 1 (MYPT1) after treatment with an agonistic anti-LTβR antibody for cytoskeleton reorganization in FRCs. The inhibition of MLCK activity induced changes in the actin cytoskeleton organization and cell morphology in FRC. In addition, we showed the phosphorylation of MLC and MYPT1 was reduced by LTβR stimulation in cells. A DNA chip revealed the LTβR stimulation of FRC down-regulated transcripts of myosin and actin components. Collectively, these results suggest LTβR stimulation is linked to myosin regarding SF alteration in FRC.

• Journal of the Korean Applied Science and Technology
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• v.22 no.1
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• pp.84-90
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• 2005

IASL(iodo acetamide) and MSL(maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. Equatorial refiection(10,11) change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of 143${\AA}$ and 72${\AA}$ could offer information of the mass projection of population of myosin heads along the :filament axis. The slope of intensity profile of the mass projection of 143${\AA}$ and reflection of IASL is appeared and that of MSL is appeared sharply. The decrease of 215${\AA}$ reflection intensity is appeared the periodical characteristic of 143${\AA}$ reflection by spin label. The raise of MSL actin reflection at 51${\AA}$ and 59${\AA}$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we could conclude that LASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• Preventive Nutrition and Food Science
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• v.10 no.4
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• pp.378-381
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• 2005

Actin and myosin solutions and fresh ground pork were irradiated with the electron beam (e-beam) at a dose of 0, 1.5, 3.0, 5.0 and 10 kGy. The changes in SDS-PAGE pattern of 2 proteins and the salt-soluble proteins extracted from ground pork after e-beam irradiation were monitored. When the myosin solution was irradiated with e-beam, myosin was degraded completely. Complete myosin degradations were observed even with the lowest dose (1.5 kGy) of e-beam treatment. Actin was degraded with the irradiation, but to a less extent than myosin was. The degradation of actin increased as the e-beam treatment increased from 1.5 to 10.0 kGy. Among the salt-soluble proteins extracted from ground pork, myosin was degraded gradually when the e-beam dose increased from 1.5 up to 10.0 kGy. Similar gradual increase in the degradation of actin also occurred with the increase of irradiation. Increases of 2 low molecular weight compounds (<29 kDa) were observed when the irradiation dose increased from 1.5 to 10.0 kGy. These 2 molecules are thought to be the breakdown products produced from the degradation of major salt-soluble proteins, myosin and actin. The salt-soluble protein content of ground pork did not change with the e-beam irradiation.