• Journal of Animal Science and Technology
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• 제64권3호
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• pp.481-499
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• 2022

This study aims to determine the effects of D-methionine (D-Met) isomer and the methionine precursor 2-hydroxy-4-methylthiobutanoic acid i (HMBi) supplementation on milk protein synthesis on immortalized bovine mammary epithelial cell (MAC-T). MAC-T cells were seeded using 10-cm dishes and cultured in Dulbecco's modified Eagle's medium/F12 (DMEM/F12) basic medium. The basic medium of DMEM/F12 was replaced with the lactogenic DMEM/ F12 differentiation medium when 90% of MAC-T cells reached confluency. The best dosage at 0.6 mM of D-Met and HMBi and incubation time at 72 h were used uniformly for all treatments. Each treatment was replicated six times wherein treatments were randomly assigned in a 6-well plate. Cell, medium, and total protein were determined using a bicinchoninic acid protein assay kit. Genes, proteomics and metabolomics analyses were also done to determine the mechanism of the milk protein synthesis pathway. Data were analyzed by two-way analysis of variance (ANOVA) with supplement type and plate as fixed effects. The least significant difference test was used to evaluate the differences among treatments. The HMBi treatment group had the highest beta-casein and S6 kinase beta-1 (S6K1) mRNA gene expression levels. HMBi and D-Met treatments have higher gene expressions compared to the control group. In terms of medium protein content, HMBi had a higher medium protein quantity than the control although not significantly different from the D-Met group. HMBi supplementation stimulated the production of eukaryotic translation initiation factor 3 subunit protein essential for protein translation initiation resulting in higher medium protein synthesis in the HMBi group than in the control group. The protein pathway analysis results showed that the D-Met group stimulated fructose-galactose metabolism, glycolysis pathway, phosphoinositide 3 kinase, and pyruvate metabolism. The HMBi group stimulated the pentose phosphate and glycolysis pathways. Metabolite analysis revealed that the D-Met treatment group increased seven metabolites and decreased uridine monophosphate (UMP) production. HMBi supplementation increased the production of three metabolites and decreased UMP and N-acetyl-L-glutamate production. Taken together, D-Met and HMBi supplementation are effective in stimulating milk protein synthesis in MAC-T cells by genes, proteins, and metabolites stimulation linked to milk protein synthesis.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.247-248
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.241-242
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.398-399
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• 1989

• Journal of Nutrition and Health
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• 제29권8호
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• pp.874-880
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• 1996

The effects of an anabolic steroid, nandrolone phenylpropionate(NPP), on body weight gain and body protein, and muscle protein metabolism were inestigated in adrenocorticotrophic hormone(ACTH)-treated male and female rats. Daily injections of 100ug/day of ACTH for 7-8 days caused a cessation of growth in females and a net loss of body weight in males which were associated with significant reductions in body protein content. However, food intake was not affected by ACTH in either sex. The weight, protein content and fractional rate of protein synthesis, measured in vivo, of gastrocnemius muscle were all significantly reduced in both sexes. NPP at a dose of 4mg/kg body weight prevented the reduction in body weight gain in ACTH-treate females but not in males. However, boy protein content was increased by NPP in both sexes which was associated with increases in the weight, protein content and fractional rate of protein synthesis of gastrocnemius muscle. ACTH treatment caused a marked increase in plasma concentrations of corticosterone in both sexes. NPP suppressed much of the increases in corticosterone concentrations in both sexes. The results of the present study suggest that NPP exerts at least part of its anabolic effect by reducing plasma concentrations of catabolic glucocorticoid hormones, through suppressing the response of the adrenals to ACTH.

• 한국식품영양학회지
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• 제30권2호
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• pp.371-377
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• 2017

Muscle atrophy is characterized by a decrease in the mass of the muscle. With an increase in life expectancy and chronic illnesses, the incidence of muscle atrophy is increasing and the quality of life of patients is decreasing. Thus, reducing muscle atrophy is of high clinical and socio-economic importance. Mistletoe is a semi-parasitic plant that has been used as a traditional medicine in many countries to treat various human illnesses. It has been reported that Korean mistletoe extract (KME) has diverse biological functions including anti-tumor, anti-oxidant, anti-diabetic, anti-obesity properties, and extension of lifespan. Especially, we have recently reported that KME improves exercise endurance in mice, indicating its beneficial roles in enhancing the capacity of skeletal muscle. In this study, we investigated whether KME could activate the signaling pathway related to protein synthesis in a mouse model of muscle atrophy. Interestingly, KME efficiently activated the Akt/mTOR pathway, and Akt and mTOR are important signaling hub molecules for the acceleration of protein synthesis in muscle cells. In addition, KME also increased the activity of S6 kinase which is involved in the regulation of muscle cell size. Moreover, the ERK activity, required for transcription of ribosomal RNA for protein synthesis, was also enhanced in KME-treated mouse muscle. These data support the idea that KME increases muscle mass via increased protein synthesis. Our findings also suggest that Korean mistletoe might be a promising candidate for the development of functional foods that are beneficial for preventing muscle atrophy.

• 한국동물학회지
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• 제36권3호
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• pp.416-424
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• 1993

홍모기 난소에서 일어나는 난황단백질의 합성을 조사하였다. 지방체의 난황단백질합성양과 난소에 축적되는 난황단백질의 양을 rocket immunoelectorphoresis 방법과 in vitro organ culture 방법으로 조사한 결과 지방체에서의 난황단백질 합성을 흡혈 후 6시간째 부터 시작되어 24시간에 최대의 합성양을 나타낸 후 48시간 이내에 완료되었으며, 난소내로의 축적은 6시간부터 시작되어 60시간까지 계속되었다. 흡혈 후 0, 24, 48, 72시간된 난소추출물을 전기영동 및 Western blotting한 결과 24시간된 난소에서는 한종류의 난황단백질이 존재한 반면, 48, 72시간된 난소에서는 두종류의 난황단백질이 나타났다. 흡혈 후 48시간된 난소와 지방체를 $^3$H-leucine이 함유된 배지에서 배양하였을 때 지방체에서는 단백질의 합성이 거의 일어나지 않았으나 난소에서는 난황단백질을 포함한 다량의 단백질합성이 일어났다. Crossed immunoelectrophoreses의 결가 YP1과 YP2는 분자량에서는 차이를 보이나 면역성은 동일한 것으로 나타났다. 이상의 결과 홍모기에서는 난소에서도 난황단백질의 합성이 일어나는 것으로 나타났다.

• BMB Reports
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• 제31권2호
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• pp.201-208
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• 1998

Amino acid analogs, like other inducers of stress response, induce the synthesis of stress proteins in mammalian cells. In this study, Drosophila Kc cells, in which translation is tightly controlled during stress response, was treated with proline analogs, L-azetidine-2-carboxylic acid (AzC) and 3,4-dehydro-L-proline (dh-P). Kc cells exposed to AzC or dh-P induced the synthesis of several proteins which had the same molecular weights as known heat shock proteins. However, in Kc cells, normal protein synthesis still continued in the presence of amino acids analogs unlike in heat-shocked cells. For the induction of stress response, the incorporation of dh-P into the protein was not essential, but the incorporation of AzC was. The stress protein synthesis was regulated mainly at the transcriptional level by AzC, whereas it was regulated by dh-P at the transcription level and possibly posttranscription level. During recovery, the stress protein synthesis stopped sooner in analog-treated cells than in heat-shocked cells even though the accumulated amount of Hsp70 was much less in proline analogstreated cells. It could be concluded that the proline analogs, AzC and dh-P, induced stress response through a different mechanism from heat shock.

• 한국동물학회지
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• 제28권2호
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• pp.71-84
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• 1985

성게의 일종인 Hemicentrotus pulcherrimus에서 수정전에 이미 축적되었던 mRNA의 활성화 변화를 알아보기 위하여 초기 발생동안의 RNA와 단백질 합성에 관하여 연구하였다. 미수정란에서는 RNA와 단백질의 합성들이 대단히 낮았다. 그러나 수정과 함께 RNA합성은 크게 변하지 않은 반면, 단백질합성은 크게 활성화되었다. RNA와 단백질 합성율이 병행적으로 변하지는 않지만, 포배와 낭배에서 크게 증가함을 볼 수 있었다. 단백질합성은 양적으로 뿐만 아니라 질적으로도 발생단계에 따라 변하는 사실을 이차원 전기영동에 의한 연구를 통하여 확인할 수 있었다.

• KSBB Journal
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• 제21권4호
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• pp.302-305
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• 2006

PCR증폭기술 및 무세포 단백질 발현 기술의 융합을 통하여, 여러 형태로 서열의 일부가 결손된 단백질들을 고속으로 발현할 수 있는 시스템을 구축하였다. Exonuclease 및 endonuclease에 대한 mRNA의 안정성 향상을 통하여, PCR 증폭을 통해 획득한 선형 DNA로부터의 안정적인 단백질 발현이 가능하였다. 동일한 플라스미드로부터 출발하여 수 시간 이내에 C-말단의 아미노산서열이 순차적으로 제거된 다양한 형태의 트랜스아미나제 Vf의 활성변화를 확인할 수 있었으며 이같은 기술은 각종 효소 단백질의 서열-활성 상호관계의 연구를 위한 유용한 기반을 제공할 것으로 기대된다.