• Animal Bioscience
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• 제35권1호
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• pp.96-104
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• 2022

Objective: Sarcoplasmic proteins include proteins that play critical roles in biological processes of living organisms. How seasons influence biological processes and meat quality of postmortem muscles through the regulation of protein phosphorylation remain to be investigated. In this study, the phosphorylation of sarcoplasmic proteins in pork longissimus muscle was investigated in four seasons. Methods: Sarcoplasmic proteins were extracted from 40 pork carcasses (10 for each season) and analyzed through ProQ Diamond staining for phosphorylation labeling and Sypro Ruby staining for total protein labeling. The pH of muscle, contents of glycogen and ATP were measured at 45 min, 3 h, and 9 h postmortem and the water (P_2b, P₂₁, and P₂₂) was measured at 3 h and 9 h. Results: A total of 21 bands were detected. Band 8 (heat shock cognate 71 kDa protein; heat shock 70 kDa protein 1B) had higher phosphorylation level in summer than that in other seasons at 45 min postmortem. The phosphorylation levels of 3 Bands were significantly different between fast and normal pH decline groups (p<0.05). The phosphorylation levels of 4 bands showed negative associations with immobilized water (P₂₁) and positive association with free water (P₂₂). Conclusion: The phosphorylation levels of sarcoplasmic proteins involved in energy metabolism and heat stress response at early postmortem time differed depending on the seasons. These proteins include heat shock protein 70, pyruvate kinase, phosphoglucomutase-1, glucose-6-phosphate isomerase, and carbonic anhydrase 3. High temperatures in summer might result in the phosphorylation of those proteins, leading to pH decline and low water holding capacity.

• 한국식품과학회지
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• 제21권2호
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• pp.173-179
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• 1989

본 연구는 도살직후 저장온도와 저장시간이 PSE이상 돈육의 단백질 변성에 미치는 영향을 DSC를 이용하여 육단백질의 열변성, 열에 대한 안정성과 근장단백질 용해성을 검토하였으며 그 결과를 요약하면 다음과 같다. 도살후 PSE육의 저장온도가 상승됨에 따라, 저장시간이 경과됨에 따라 DSC-thermodiagram의 myosin+sarcoplasmic protein의 변성이 나타나는 endotherm enthalpy가 감소하였다. 도살 후 $1{\sim}4$시간 동안 PSE육의 저장온도가 $20^{\circ}C$일 때 myosin+sarcoplasmic protein의 변성이 적었으나 $25^{\circ}C$ 이상일 때는 단백질 변성이 증가하였다. PSE육의 drip 손실은 도살 후 가능한 신속히 $2^{\circ}C$에 냉각시킨 육에서 최고를 나타냈다. 그러나 도살직후 수시간 동안 $32{\sim}38^{\circ}C$에 항온시킨 PSE육은 wateriness가 심하여 drip손실이 현저히 증가하였다. PSE육의 창백성은 도살직후 육온을 $20^{\circ}C$로 급속냉각함으로써 개선할 수 있었다. PSE육의 myosin+sarcoplasmic protein 의 변성이 심할 수록 발생하는 drip 양이 증가하였다.

• 한국동물학회지
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• 제33권2호
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• pp.191-199
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• 1990

토끼의 골격근에서 근소포체를 순수 분리하여 SDS-polyacrylamide gel전기영동법과 125 I-concanavalin A표지법으로 단백질과 당단백질의 조성을 조사하였다. 전기영동사에 나타난 대표적인 단백질은 $Ca^2$+-AThase, 80 Kd protein,calsequestrin,high affinity calcium binding protein, intrinsic glycoprotein이었으며, 160 Kd protein, 94 Kd protein,38 Kd protein, 34 Kd protein,24 Kd proteins도 존재하였다.특히, 막성계에 있는 heak protein으로 알려져 있는 80 Kd protein은 본 연구를 통해 주로 근소포체의 terminal cisternae에 들어 있음이 확인되었다. 한편 125 I-concanavalin A표지에 의해 전기영동성에 나타난 대표적인 당단백질은 160 Kd glycoprotein, 94 Kd glycoprotein, calsequestrin, intrinsic glycoprotein의 4종이었다. 이 가운데 94 Kd glycoprotein은 94 Kd glucose-regulated protein으로 추정되며, 본 연구를 통해 근소포체에서도 특히 T-tubule에 다량으로 존재함이 밝혀졌다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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• pp.56-56
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• 2002

Muscle contraction and relaxation are regulated by the sarcoplasmic reticulum (SR)-mediated $Ca^{2＋}$ release and $Ca^{2＋}$ uptake. The SR functions are closely related with the proteins residing in the SR such as ryanodine receptor, $Ca^{2＋}$-ATpase, calsequestrin, triadin and junctin. In an effort to further identify important functional SR proteins, experiments of sucrose-density gradient of SR fractionation, concanavalin A treatment, 2D gel electrophoresis, $^{45}$ Ca$^{2+}$ overlay, Strains-all staining, and peptide finger printing (PFP) were carried out.(omitted)d)

• 한국축산식품학회지
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• 제34권3호
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• pp.307-315
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• 2014

pH adjustment would be of advantage in improving the water holding capacity of muscle proteins. The objective of this study was to evaluate the addition of fish sarcoplasmic protein (SP) solution, which was adjusted to pH 3.0 or 12.0, neutralized to pH 7.0, and lyophilized to obtain the acid- and alkaline-treated SP samples, on the functional properties of the chicken myofibrillar protein induced by microbial transglutaminase (MTG). The solubility of alkaline-treated SP was higher than that of the acid counterpart; however, those values of the two pH-treated samples were lower than that of normal SP (p<0.05). All SP solutions were mixed with myofibrillar proteins (MP) extracted from chicken breast, and incubated with MTG. The shear stresses of MP with acid- and alkaline-treated SP were higher than that of normal SP. The thermal stability of MP mixture reduced upon adding SP, regardless of the pH treatment. The breaking force of MP gels with acid-treated SP increased more than those of alkaline-treated SP, while normal SP showed the highest value. The MP gel lightness increased, but cooking loss reduced, with the addition of SP. Smooth microstructure of the gel surface was observed. These results indicated that adjusting the pH of SP improved the water holding capacity of chicken myofibrillar proteins induced by MTG.

• BMB Reports
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• 제51권8호
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• pp.378-387
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• 2018

Skeletal muscle contracts or relaxes to maintain the body position and locomotion. For the contraction and relaxation of skeletal muscle, $Ca^{2+}$ in the cytosol of skeletal muscle fibers acts as a switch to turn on and off a series of contractile proteins. The cytosolic $Ca^{2+}$ level in skeletal muscle fibers is governed mainly by movements of $Ca^{2+}$ between the cytosol and the sarcoplasmic reticulum (SR). Store-operated $Ca^{2+}$ entry (SOCE), a $Ca^{2+}$ entryway from the extracellular space to the cytosol, has gained a significant amount of attention from muscle physiologists. Orai1 and stromal interaction molecule 1 (STIM1) are the main protein identities of SOCE. This mini-review focuses on the roles of STIM proteins and SOCE in the physiological and pathophysiological functions of skeletal muscle and in their correlations with recently identified proteins, as well as historical proteins that are known to mediate skeletal muscle function.

• 한국축산식품학회지
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• 제41권4호
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• pp.650-663
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• 2021

The objective of this study was to examine the relationship between meat quality attributes and the changes of sarcoplasmic protein acetylation and myofibrillar protein acetylation in lamb longissimus thoracis et lumborum muscles at different postmortem phases. Protein acetylation, color, pH, shear force, myofibril fragmentation index and cooking loss were measured. The total level of acetylated sarcoplasmic proteins showed a negative relation with pH, a positive relation with a^*, b^* and cooking loss at the pre-rigor phase. Sarcoplasmic proteins acetylation affected postmortem pH by regulating glycolysis, which in turn affects color and cooking loss. The total level of acetylated myofibrillar proteins showed a positive relation with shear force at the pre-rigor phase. Myofibrillar proteins acetylation affected meat tenderness by regulating muscle contraction. This study indicated that acetylation played a regulatory role of meat color, water-holding capacity, and tenderization process at early postmortem.

• 한국식품영양학회지
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• 제6권2호
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• pp.73-80
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• 1993

In order to examine food components of coho salmon and rainbow-trout, We analyzed the composition of protein, amino acids and total lipids. The coho salmon muscle contained about 19.3% of protein with the composition of 29.9% in sarcoplasmic protein, 56.3oA in myofibrillar protein 12.5% alkali soluble protein and 2.6% in stroma. Those of rainbow-trout contained 34.1%, 56.4%, 8.3% and 2.9%, respectively. The sarcoplasmic and myofibrillar protein were composed of 13 subunits in coho salmon, and 16 and 15 subunits in rainbow-trout. Judging from the contents of essential amino acids, both muscle proteins were complete proteins. The most remarkable feature of free amino acids was that a large amount of dipeptide anserine was present with fairly lower levels of 1 methyl histidine, taurine, histidine, alanine and glycine in both muscle extracts. The total fatty acids of coho salmon was composed of 31.49% polyenes, 43.79% monoenes and 24.73% saturates. The composition of total fatty acid of coho salmon muscle was not different from that of rainbow-trout muscle.

• BMB Reports
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• 제43권3호
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• pp.158-163
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• 2010

Calumenin is a multiple EF-hand $Ca^{2+}$-binding protein located in the endo/sarcoplasmic reticulum of mammalian hearts. Calumenin belongs to the CREC family of $Ca^{2+}$-binding proteins having multiple EF-hands. $Ca^{2+}$ homeostasis in the sarcoplasmic reticulum (SR) of mammalian hearts is maintained by RyR2, SERCA2 and other associated SR resident proteins. Evidence suggests that calumenin interacts with RyR2 and SERCA2, and therefore changes in the expression of calumenin could alter $Ca^{2+}$ cycling in mouse heart. In this review, current knowledge of the biochemical and functional roles of calumenin in mouse heart is described.

• 한국축산식품학회지
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• 제20권2호
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• pp.146-151
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• 2000

The objective of this study was to investigate the characteristics on the thermal denaturation of free drip released from pork loin during chilled storage using DSC(differential scanning calorimetry). DSC thermogram of drip released from normal pork(NORD) was characterized by a minor peak and two major peaks with temperature maxima at $61.5^{\circ}C$, $71.7^{\circ}C$ (associated with sarcoplasmic proteins) and $84.3^{\circ}C$ (associated with protein-protein interaction and aggregation). In the denaturation temperature of drip released from PSE pork (PSED), the peak(Tmax) at $59.0^{\circ}C$ was reduced by $2.5^{\circ}C$. When the thermograms were divided into segments correponding to the three peaks, $\Delta$H2 was shown to be reduced by 10% in PSED as compared to NORD. With the decrease in the solubility of sarcoplasmic proteins in PSE muscle, there was a corresponding increase the drip loss during the storage.