• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.401-406
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• 1997

This study was carried out to compare the extractability and ATPase activity of actomyosin extracted shank, rib and loin muscle of beef meat stored at 8$^{\circ}C$. The extractability of actomyosin in shank, rib and loin muscle were 36.74, 72.55 and 56.77mg/g early in the storage, respectively. The extractability of the rib and loin muscle were similar, the shank muscle was processed differently with their. The Mg- and Ca-ATPase activity of the shank muscle rised to 3 days, but decreased the 6th day. And Mg- and Ca-ATPase activity of the rib muscle was similar during storage period, the loin muscle made a slow descent. The strength of Mg- and Ca-ATPase activity showed in the order shank, rib and loin muscle. The EDTA-ATPase activity of the shank and rib muscle was difference according to storage period and ionic strength, but the loin muscle was increase in succession with magnitude of ionic strength.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.721-733
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• 2019

Objective: The objectives of this study were to investigate the thermal gelation properties and molecular forces of actomyosin extracted from two classes of chicken breast meat qualities (normal and pale, soft and exudative [PSE]-like) during heating process to further improve the understanding of the variations of functional properties between normal and PSE-like chicken breast meat. Methods: Actomyosin was extracted from normal and PSE-like chicken breast meat and the gel strength, water-holding capacity (WHC), protein loss, particle size and distribution, dynamic rheology and protein thermal stability were determined, then turbidity, active sulfhydryl group contents, hydrophobicity and molecular forces during thermal-induced gelling formation were comparatively studied. Results: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that protein profiles of actomyosin extracted from normal and PSE-like meat were not significantly different (p>0.05). Compared with normal actomyosin, PSE-like actomyosin had lower gel strength, WHC, particle size, less protein content involved in thermal gelation forming (p<0.05), and reduced onset temperature ($T_o$), thermal transition temperature ($T_d$), storage modulus (G') and loss modulus (G"). The turbidity, reactive sulfhydryl group of PSE-like actomyosin were higher when heated from $40^{\circ}C$ to $60^{\circ}C$. Further heating to $80^{\circ}C$ had lower transition from reactive sulfhydryl group into a disulfide bond and surface hydrophobicity. Molecular forces showed that hydrophobic interaction was the main force for heat-induced gel formation while both ionic and hydrogen bonds were different significantly between normal and PSE-like actomyosin (p<0.05). Conclusion: These changes in chemical groups and inter-molecular bonds affected protein-protein interaction and protein-water interaction and contributed to the inferior thermal gelation properties of PSE-like meat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.271-279
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• 1984

Effects of temperature and additives on the stability of actomyosin extracted from skeletal muscle of Israeli carp, Cyprinus carpio nudus, were studied by analyzing free SH-group, ATP-sensitivity and Ca-ATPase activity. The used additives were sucrose, sorbitol, Na-glutamate and L-cysteine. Furthermore, the denaturation constant($K_D$), protective effect(${\Delta}E/M$) and the other thermo-dynamic parameters on protein denaturation are systematically discussed. The actomyosin showed $4.12{\sim}4.68 mg/ml$ in protein concentration, $2.63{\sim}2.93\%$ in ribonucleic acid to the protein, $1:2.20{\sim}2.63$ in the binding ratio of myosin and actin, $4.33{\sim}5.26\%$ in fat content, 109.78 in ATP-sonsitivity, $0.159{\sim}0.201\;{\mu}M-Pi/min/mg-protein$ in Ca-ATPase activity and $3.3{\sim}3.4M/10^5$g-protein in free SH-group content. The first-order rate plots were obtained on the decrease of Ca-ATPase activity and ATP-sensitivity with an increase in temperature, while the free SH-group was increased to $60^{\circ}C$ and decreased rapidly above the temperature. The half-life of Ca-ATPase activity on the actomyosin Ca-ATPase was 280 min at $12^{\circ}C$, 125 min at $20^{\circ}C$, 55 min at $30^{\circ}C$ and 13 min at $40^{\circ}C$, and activation energy, activation enthalpy, activation entropy and free energy of the proteins at $20^{\circ}C$ wene 5,395 cal/mole, 4,814 cal/mole, -40.42 e.u. and 17,626 cal/mole, respectively. The protective effect of the additives on the actomyosin Ca-ATPase showed that the most effective material is $3\%$ sorbitol and followed in the order of $8\%$ Na-glutamate, $1\%$ sucrose and $1\%$ L-cysteine. The actomyosin was more stable at $-30^{\circ}C$ than at $0^{\circ}C$ and $-20^{\circ}C$. and when the additives were used in the low temperature storage, $8\%$ Na-glutamate was the most effective. $3\%$ sorbitol, $1\%$ sucrose and $1\%$ L-cysteine was to become lower in the order.

• The Korean Journal of Pharmacology
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• v.12 no.1
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• pp.23-29
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• 1976

Aconiti tuber butanol fraction has been recently known to have stimulatory effect on myocardial contractility. In the present study, the possibility that the Aconiti tuber butanol fraction acts directly on contractile proteins of myocardium has been investigated using natural actomyosin extracted from dog heart. It revealed that Aconiti tuber butanol fraction in concentrations from $10^{-2}{\sim}10^{-7}\;gm/ml$ had no stimulatory effect on either the $Mg^{++}$ or $Ca^{++}$-activated adenosinetriphosphatase activity of cardiac actomyosin. And no direct $Ca^{++}$-like action of the drug on cardiac actomyosin was also found. Aconiti tuber butanol fraction in concentrations above $10^{-4}\;gm/ml$, however, was somewhat stimulatory on superprecipitation of actomyosin and markedly inhibited the membrane bound $Na^+-K^+$-activated ATPase activity. In these connections, the positive inotropic action of Aconiti tuber butanol fraction on myocardium thus does not seem to reflect a direct interaction with contractile proteins, but the drug seem to stimulate myocardial contractility through the actions on the membrane transport of $Ca^{++}$.

• 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.

• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.12-16
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• 1999

Denaturation of actomyosin from the obliquely striated mantle muscle of squids (Todarodes pacificus) was studied by measuring the changes in $Ca^{2+}$-ATPase activity, relative viscosity, and solubility during frozen storage at three different temperature zones of maximum ice crystal formation $(-3^{\circ}C,\;-\;-5^{\circ}C)$, the eutectic point $(-11^{\circ}C)$, and $-20^{\circ}C$. The logarithms of $Ca^{2+}$-ATPase activity, relative viscosity and solubility of the actomyosin solutions (0.6 M KCl) and suspensions (0.05 M KCl) tended to decrease during frozen storage. The denaturation of squid actomyosin at the zone of maximum ice crystal formation significantly differed by only two degree of temperature difference between $-3^{\circ}C$ and $-5^{\circ}C$, and it (0.05 M KCl) at $-3^{\circ}C$ was less than those of other temperature. The denaturation at $-11^{\circ}C$ was more rapid than at $-5^{\circ}C$. The logarithms of $Ca^{2+}$ -ATPase activity, relative viscosity, and solubility were changed slower in the suspensions (0.05 M KCl) than the solutions (0.6 M KCl) at all experimental temperatures.

• Applied Biological Chemistry
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• v.14 no.2
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• pp.165-169
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• 1971

From both breast and leg muscle of 12 week-old broiler chicken held for aging in slushed ice and dry chilling at $33-35^{\circ}F$., myosin, actomyosin and other nitrogenous fractions were extracted with KCl-phosphate buffer for various periods from 1 hr. to 25 hr. post-mortem. The changes in extractable nitrogen occurred mainly as a result of decrease in extractability of myosin and to some extent, increase in extractability of actomyosin. Changes in stroma, sarcoplasmic and NPN fractions were small. Myosin extractability decreased rapidly during the first 3 hr. post-mortem and then reduced Continuously in both leg muscle and breast muscle during wet chilling. The decrease of myosin extractability in leg muscle was much more than that in breast muscle, and then the extractability increased after 17 hr. post-mortem in dry chilling. Actomyosin was extracted at low consistent level in wet chilling, while it increased considerably after 17 hr. post-mortem in dry chilling. The tendency was similar in both breast and leg muscle.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.157-163
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• 2009

This study was conducted for the isolation, purification, and characterization of a protease from Korean pear, to see its proteolytic activity on chicken actomyosin and to find the optimum pH and temperature of activity on chicken actomyosin. The protease was isolated from crude extract of Korean pear by ammonium sulfate precipitation. Further purification was done by DEAE-Sepharose ion-exchange chromatography, Mono-Q and Mini-Q column chromatography. The purified enzyme gave a single protein band on SDS polyacrylamide gel electrophoresis and the molecular weight was found to be 38 kDa. The specific activity of purified enzyme was 34,907 unit/mg with 25 fold purification and the yield was 2%. The purified enzyme incubated with chicken actomyosin showed high activity. The optimum pH and temperature for enzyme activity on chicken actomyosin were 6.5 and $70^{\circ}C$, respectively. A protease was purified from Korean pear for the first time and characterized. It was found to be promising for meat tenderization.

• 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.