• Journal of Life Science
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• v.7 no.4
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• pp.336-341
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• 1997

This study was conducted to investigate the effects of carcass grade on the hardness, myofibrillar fragmentations index, protein extractability and Mg-ATPase activity of myofibril and actomyosin obtained from 1, 2, 3 and D carcass grade)subgrade) in Korean native cow. Proximate component, hardness, chewiness, myofibril fragmentation index, protein extractability and Mg-ATPase activity if myofibril or actomyosin were not significantly different between 1st and 2nd carcass grade loin. The hardness and chewiness of 2nd carcass grade loin's were significantly lower than 3th grade loin's, but the myofibril fragmentation index, sarcoplasmic protein extractability and Mg-ATPase activity of myofibril were higher. The myofibrillar protein extractability and Mg-ATPase activity of actomyosin obtained from 3th carcase grade loin's were significantly higher than D grade loin's, but the hardness, chewiness and stroma protein extractability were lower. In conclusion, the degree of toughness in Korean native cow's loin was not significantly different between 1st and 2nd grade, but 3rd and D carcass grade were significantly higher, regardless of before and after aging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.292-298
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• 1999

Myofibril and actomyosin were prepared from red muscle and white muscle of fresh water fish and sea water fish, and their biochemical characteristics and SDS PAGE patterns of myofibril were compared. SDS PAGE analysis showed that electrophoretic patterns of myofibril were similar be tween white muscle and red muscle, while difference of 30kDa component of myofibril was detected between fresh water fish and sea water fish. When myofibril were treated with trypsin, difference in hydrolysis of heavy chain was observed between white muscle and red muscle. In activities of Ca ATPase, Mg ATPase, EDTA ATPase and ATPase activity pH curve, myofibrillar protein from fresh water fish showed higher specific activity than those from sea water fish.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.849-860
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• 2022

The myofibril protein (MP) isolate-saccharide graft reactions was prepared using the Maillard reaction with saccharides. The effects of various saccharides on protein functionality and quality of the Maillard reaction were investigated and compared with those of MP. The grafting degree of the MP isolate-saccharide graft reaction was significantly higher in the reducing sugar-treated groups (lactose, glucose, fructose, and palatinose). The browning intensity of the MP isolate-saccharide graft reaction with fructose, sucrose, and erythitol was higher than that observed in the control reaction (p<0.05). MP that reacted with reducing sugars (glucose, fructose, palatinose, and lactose) had fainter bands than MP that reacted with non-reducing sugars (sucrose, erythitol, trehalose, sorbitol, and xylitol). MPs conjugated with glucose exhibited higher protein solubility. The palatinose and lactose treatments were maximum in water binding capacity, though no significant difference in oil binding capacity among the saccharide treatments was observed. The emulsion stability of the MP isolate-saccharide graft reaction with palatinose and erythitol was higher than that of the control reaction. Therefore, reducing sugars have good protein functionality in the MP isolate-saccharides graft reaction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.1
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• pp.82-87
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• 1985

Some biological activities showed as ATPase activity of myofibril, actomyosin and myosin extracted from chicken leg and pectoral skeletal muscle were investigated. The $Mg^{+2}$-ATPase activity at 0.05 M KCl were 0.82, 0.38 and 0.11 ${\mu}mole$ Pi/mg protein/min. in actomyosin, myofibril and myosin from pectoral muscle while 0.71, 0.32 and 0.08 ${\mu}mole$ Pi/mg protein/min. in actomyosin, myofibril and myosin from leg muscle. EDTA-ATPase activity at 0.6M KCl were 0.80, 0.42 and 0.40 ${\mu}mole$ Pi/mg protein/min. in actomyosin, myofibril and myosin from pectoral muscle. In case of leg muscle, that activity was noted as 0.69, 0.33 and 0.28 ${\mu}mole$e Pi/mg protein/min in proteins. ATPase activity of myosin from leg and pectoral muscle were inhibited in 10% at a higher concentration of $Mg^{+2}$ than molar concentration of EDTA, and the ATPase activity was increased to 400% compared with control at $10^{-3}M$ of $Ca^{+2}$. Actomyosin from pectoral muscle was solubilized at 0.1 M KCl above and that from leg muscle was solubilized at 0.15 M KCl above. In case of myosin, pectoral muscle was solubilized at 0.25M KCI above and leg muscle was solubilized at 0.30M KCl above.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.353-357
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• 1984

The myofibril prepared from PSE (pale, soft, exudative) porcine meat was modified by reacting with succinic anhydride and the chemical and functional properties of modified myofibrils were investigated. $No\;Ca^{2+}-and\;Mg^{2+}-ATPase$ activity were observed irrespective of the degree of succinylation. Isoelectric point of the succinylated myofibril changed to around pH 3 from the pH 5 of unmodified myofibril. Salt soluble property was not affected by changing the salt concentration. The modified myofibril in aqueous solution did not coagulate during heating at $98^{\circ}C$ for 10 min. Water absorption ability was not improved but emulsion capacity was improved a little by succinylation.

• Journal of Life Science
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• v.7 no.4
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• pp.329-335
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• 1997

This study was conducted to investigate the effect of dietary fiber(DF) levels on the meat quality in colored broiler. Colored broiler were fed on containing corn-soy basal diet(DF 5%) and high level(DF 6,7 and 8%) of dietary fiber diets for 7 weeks. Dietary fiber level of diet was make up by adding some alffalfa meal. Colored broiler meats were stored at 3$\circ$ for 24hr after skaughter, and used to analyze physico-chemical properties. Proximate component, pH, shear force value, myofibril fragmentation index, water holding capacity, cooking loss, protein extractability, fatty acid composition, Hunter's L, a value and palatability of cooked meat were not significantly affected by dietary fiber levels, whereas the Hunter's value of meat was significantly affected bty dietary fiber levels for the final period of feeding. Crude protein content, myofibril fragmentation index, water holding capacity, protein extractability and Hunter's b value of breast meat's were higher than thigh meat's, but crude fat content, pH, shear force value, cooking loss, palmitoleic acid, linolenic acid, and Hunter's a value were lower, regardless of dietary fiber level.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.457-462
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• 2007

Effects of sonication on water-solubilization of myofibril from breast muscle of spent hen effects investigated in this study. To evaluate effect of salt concentration and pH, salt concentration was varied with range from 0.1 to 0.8 M, and pH was varied with range from 6.0 to 8.0. Solubility, SDS-PAGE, viscosity and ATPase activity of sonicated myofibril were measured. Solubility of myofibrillar protein containing 0.1 M NaCl at pH 8.0 after sonication was above 90%. Main components of soluble protein by SDS-PAGE were myosin heavy chain and actin. That is, it indicated breaking of myofibril structure by sonication. Also, viscosity of soluble protein increased, but Ca- and Mg-ATPase activities decreased by increasing sonication time. From these results, we concluded that most of myofibrillar proteins were denatured by sonication.

• 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.

• Biomedical Science Letters
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• v.13 no.4
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• pp.251-261
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• 2007

A myofiber of skeletal muscle is composed of myofibrils, sarcolemma (plasma membrane), and constameres, which anchor the myofibrils to the sarcolemma. Achvillin is a recently identified F-actin binding muscle protein, co-isolates with dystrophin and caveolin-3 in low-density sarcolemma of striated muscle, and colocalizes with dystrophin at costameres, the specialized adhesion sites in muscle. Archvillin also binds to nebulin and localizes at myofibrillar Z-discs, the lateral boundaries of the sarcomere in muscle. However other roles of archvillin on the dynamics of myofibrillogenesis remain to be defined. The goal of this study is, by using siRNA-mediated gene silencing technique, to investigate the effect of archvillin on the dynamics of myofibrillogenesis in cell culture of a mouse skeletal myogenic cell line (C2C12), where presumptive myoblasts withdraw from the cell cycle, fuse, undergo de novo myofibrillogenesis, and differentiate into mature myotubes. The roles of archvillin in the assembly and maintenance of myofibril and during the progression of myofibrillogenesis induced in skeletal myoblast following gene silencing in the cell culture were investigated. Fluorescence microscopy demonstrated that the distribution of archvillin was changed along the course of myofibril assembly with nebulin, vinculin and F-actin and then located at Z-lines with nebulin. Fluorescence microscopy demonstrated that knockdown of mouse archvillin expression led to an impaired assembly of new myofibrillar clusters and delayed fusion and myofibrillogenesis although the mouse archvillin siRNA did not affect those expressions of archvillin binding proteins, such as nebulin and F-actin. This result is corresponded with that of RT-PCR and western blots. When the perturbed archvillin was rescued by co-transfection with GFP or Red tagged human archvillin construct, the inhibited cell fusion and myotube formation was recovered. By using siRNA technique, archvillin was found to be involved in early stage of myofibrillogenesis. Therefore, the current data suggest the idea that archvillin plays critical roles on cell fusion and dynamic myofibril assembly.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.443-449
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• 1986

In order to investigate the general characteristics of ATPase and ATPase thermostability between porcine white muscle and red muscle, myofibrillar proteins were prepared and compared their physicochemical characteristics. SDS-polyacrylamide gel electrophoretic analyses showed that a protein band of 30,000 daltons was detected noticeably in myofibril from red muscle, but negligibly in myofibril from white muscle. The noticeable differences were found between porcine white muscle and red muscle for the activities of EDTA-ATPase, Ca-ATPase and Mg-ATPase. Myofibrillar proteins from white muscle showed higher thermostability than those from red muscle. Thermodynamic parameters, enthalpy $({\Delta}H^#)$, entropy $({\Delta}S^#)$, etc., showed characteristic variations between porcine white muscle and red muscle.