• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.21-22
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• 2004

The present study was aimed to investigate proteome affected by Panax ginseng extracts in chicken muscles. More than 300 protein spots were detected on silver staining gels. Among them. four protein spots were distinctively up-regulated by Panax ginseng treatments. The up-regulated proteins were finally identified as tropomyosin (2 spots), triosephosphate isomerase, and one unknown protein. Based on the known functions of the identified proteins. they are highly related to the muscle development and enhanced immunity in chicken. These proteins can give valuable information of biochemical roles for Panax ginseng in chicken meats.

• Journal of Life Science
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• v.14 no.5
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• pp.770-777
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• 2004

It has been previously reported that unacetylated a-tropomyosin(TM) produced in E. coli failed to bind to actin while acetylated muscle TM and Ala-Ser dipeptide fusion TM (AS-TM) bound well to actin. In order to determine the structural requirement of the amino terminus for high actin affinity, a recombinant tropomyosin (Ala-TM) that a single Ala residue was added to the amino terminus of Ala-TM was constructed, overexpressed, and purified from E. coli. Actin affinity of Ala-TM was 2.3$\times$$10^{6}$$M^{-1}$, whereas that of unacetylated TM was considerably lower than 0.1$\times$$10^{-6}$$M^{-1}$ indicating that addition of a single Ala residue to the amino terminus drastically increased, at least twenty times, actin affinity of TM. Ala-TM, however, bound to actin about three times weaker than acetylated TM and AS- TM, implying that the addition of an Ala residue was insufficient for complete restoration of high actin affinity. While Ala-TM, AS-TM, and muscle TM showed inhibition and activation of actomyosin Sl ATPase activity depending on myosin Sl concentration, the degree of inhibition and activation was different from each other. AS-TM exhibited the greatest inhibition of the ATPase at low Sl concentration, whereas the greatest activation of the ATPase was observed with muscle TM. These results, together with previous findings, strongly suggested that local structure of the amino terminus is the crucial functional determinant of TM.

• Korean Journal of Food Science and Technology
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• v.6 no.4
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• pp.199-208
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• 1974

An attempt was made to study on new method for the extraction of the regulatory proteins from myofibrils, and the procedures for the preparation of desensitized actomyosin and for complete extraction of troponin-tropomyosin complex were developed. When myofibrils were treated through the procedures developed in this study, actomyosin obtained had no Ca-sensitivity, indicating that Ca-sensitizing protein factor had been removed completely from myofibril. Consequently, it was concluded that the procedures developed in this study were convenient to test whether Ca-sensitizing proteins has been removed or not. When Mg-activated ATPase activity of myofibril were measured, the myofibrillar ATPase turned into the actomyosin type ATPase with the progress of the treatment. This result was interpreted to show that the regulatory proteins of the myofibril seems to play a cementing role on the structure of myofibril. When supernatant containing the regulatory proteins were fractionated with $(NH_4)_2SO_4$ saturation solution, regulatory proteins, ${\alpha}-actinin$ and troponia-tropomyosin complex, could be obtained and they showed their typical phyoislogical activity which modify the actin-myosin interaction. The amount of troponin-tropomyosin complex in myofibril was 72 mg per g myofibril. This result was in good agreement with the results reported by many investigators, and therefore it was concluded that our procedures for the extraction of troponin-tropomyosin complex were desirable to study on the quantitative analysis of troponin-tropomyosin complex.

• Animal cells and systems
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• v.8
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• pp.73-73
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• 2004

• The Korean Journal of Zoology
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• v.26 no.1
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• pp.1-17
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• 1983

The synthesis of myosin, actin, tropomyosin and troponin in the cultured muscle cells of chick embryo during the differentiation were analyzed. The synthesis of myosin and actin were very active prior to the myoblast fusion while the troponin synthesis became active after the fusion. Tropomyosin was synthesized practically constantly throughout the culture period. Several proteins were detected in the muscle-conditioned medium strongly suggesting that the cells in culture released polypeptides which might act on the membrane of neighboring cells cells to initiate the fusion.

• Parasites, Hosts and Diseases
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• v.39 no.1
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• pp.13-21
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• 2001

Pneumocystis carinii causes serious pulmonary infection in immuno-suppressed patients. This study was undertaken to observe the cytoskeletal proteins of P. carinii by immune-electron microscopy. P. carinii infection was experimentally induced by immunosuppression of Sprague-Dawley rats for seven weeks, and their lungs were used for the observations of this study. The gold particles localized actin, tropomyosin, and tubulin. The actin was irregularly scattered in the cytoplasm of the trophic forms but was much more concentrated in the inner space of the cell wall of the cystic forms called the inner electron-lucent layer No significant amount of tropomyosin was observed in either trophic forms or cystic forms. The tubulin was distributed along the peripheral cytoplasm and filopodia of both the trophic and cystic forms rather than in the inner side of the cytoplasm. Particularly, in the cystic forms, the amount of tubulin was increased and located mainly in the inner electron-lucent layer of the cell wall where the actin was concentrated as well. The results of this study showed that the cell wall of P carinii cystic forms is a structure whose inner side is rich in actin and tubulin. The location of the actin and tubulin in P. carinii suggests that the main role of these proteins is an involvement in the protection of cystic forms from the outside environment by maintaining rigidity of the cystic forms.

• Journal of Life Science
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• v.19 no.5
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• pp.573-580
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• 2009

It has been previously reported that the carboxyl terminal residues 276 and 277 of ${\alpha}$-tropomyosin are important for actin affinity. In order to investigate actin affinities of these two residues of skeletal (HA) and smooth (QT) muscle ${\alpha}$-tropomyosins, a series of mutant tropomyosins were constructed in which residues at either 276 or 277 were individually replaced with a cysteine residue for chemical modification. These mutants were overexpressed in E. coli as unacetylated and Ala-Ser (AS) dipeptide fusion forms. While actin affinities of unacetylated tropomyosins were considerably low, those of AS/TMs were remarkably higher than those of corresponding unacetylated tropomyosins. However, actin affinities of AS/TM24 (QC) and AS/TM29 (HC) were dramatically lower than those of other AS/TMs and were close to those of unacetylated tropomyosins. In addition, actin affinities of unacetylated TM24 (QC) and TM29 (HC) failed to be restored in the presence of troponin, unlike unacetylated TM10 (HA) and TM23 (CA). These results indicated that the presence of a cysteine residue at 277 caused a drastic decrease in actin affinity, and also that the residue 277 is important for actin affinity of ${\alpha}$-tropomyosin. Since TM23 (CA) showed high actin affinity, it may serve as a valuable tool for chemical modification studies for investigating the interaction of the carboxyl terminal residues of ${\alpha}$-tropomyosin with actin and/or troponin.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1293-1295
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• 2013

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.144-144
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• 2002

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.116.2-116
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• 2003

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