• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1126-1141
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• 2021

Recent evidence has shown that methionine (Met) supplementation can improve milk protein synthesis under hyperthermia (which reduces milk production). To explore the mechanism by which milk protein synthesis is affected by Met supplementation under hyperthermia, mammary alveolar (MAC-T) cells were incubated at a hyperthermic temperature of 42℃ for 6 h in media with different concentrations of Met. While the control group (CON) contained a normal amino acid concentration profile (60 ㎍/mL of Met), the three treatment groups were supplemented with Met at concentrations of 10 ㎍/mL (MET70, 70 ㎍/mL of Met), 20 ㎍/mL (MET80, 80 ㎍/mL of Met), and 30 ㎍/mL (MET90,90 ㎍/mL of Met). Our results show that additional Met supplementation increases the mRNA and protein levels of BCL2 (B-cell lymphoma-2, an anti-apoptosis agent), and decreases the mRNA and protein levels of BAX (Bcl-2-associated X protein, a pro-apoptosis agent), especially at an additional supplementary concentration of 20 ㎍/mL (group Met80). Supplementation with higher concentrations of Met decreased the mRNA levels of Caspase-3 and Caspase-9, and increased protein levels of heat shock protein (HSP70). The total protein levels of the mechanistic target of rapamycin (mTOR) and the mTOR signalling pathway-related proteins, AKT, ribosomal protein S6 kinase B1 (RPS6KB1), and ribosomal protein S6 (RPS6), increased with increasing Met supplementation, and peaked at 80 ㎍/mL Met (group Met80). In addition, we also found that additional Met supplementation upregulated the gene expression of αS1-casein (CSN1S1), β-casein (CSN2), and the amino acid transporter genes SLC38A2, SLC38A3 which are known to be mTOR targets. Additional Met supplementation, however, had no effect on the gene expression of κ-casein (CSN3) and solute carrier family 34 member 2 (SLC34A2). Our results suggest that additional Met supplementation with 20 ㎍/mL may promote the synthesis of milk proteins in bovine mammary epithelial cells under hyperthermia by inhibiting apoptosis, activating the AKT-mTOR-RPS6KB1 signalling pathway, and regulating the entry of amino acids into these cells.

• Journal of Nutrition and Health
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• 제13권4호
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• pp.167-176
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• 1980

This study was conducted to compare effects of various types of dietary carboh ydrates fed with different levels of protein on the protein utilization in weanling rats. Sixty male Sprague-Dawley rats weighing $60{\pm}1.3grams$ were adapted for 1 week with 77% starch-15% casein diet. Then the animals divided into 12 groups according to body weight and fed each experimental diet for two weeks. Carbodydrates used were glucose, starch, and sucrose and the amount of protein given were 0g, 1g, 3g, 5g casein/day. Protein portion of the diet was fed in two seperate feedings per day while nonprotein portion was fed ad libitum. It seemed that there was no significant difference in the protein utilization by using the different kinds of carbohydrate, but in P.E.R., N.P.U., weights of organs and protein and lipid in total carcass, glucose groups were tended to be slightly lower than starch and sucrose groups. The larger the amount of casein given, the higher were the value of body weight gain, F.E.R., weights of organs, total lipid in carcass and the amount of nitrogen retention. On the while, the larger the amount of casein given, the lower were the value of the intake of non-protein portion, P.E.R., N.P.U, and the percentage of nitrogen retention.

• Journal of Dairy Science and Biotechnology
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• 제40권3호
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• pp.134-142
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• 2022

Protein-enriched dairy powder is widely consumed to promote muscle synthesis. Recently, in Korea, elderly people have also begun consuming protein powder products to prevent muscle loss. However, these protein-enriched powders have poor flowability and hydration properties because of the fine particles of spray-dried milk protein powder. Therefore, in this study, the fluidized bed agglomeration process was used to solve these problems. The rheological and physical properties of milk protein isolate (MPI)/skim milk powder (SMP) mixtures were effectively improved via fluidized bed agglomeration. The particle size of the MPI/SMP mixtures significantly increased from 35.7-58 ㎛ to 118-136 ㎛, the flowability level improved from fair (21.4-26.3) to good (15.7-16.3), and the cohesiveness level changed from intermediate (1.27-1.36) to low (1.18-1.19) after fluidized bed agglomeration. In addition, the wetting time of the agglomerated MPI/SMP mixtures was effectively reduced to 4.67-58.3 s by fluidized bed agglomeration. These findings may be useful for manufacturing protein-enriched dairy powders with good instant properties.

• Asian-Australasian Journal of Animal Sciences
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• 제27권1호
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• pp.30-35
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• 2014

This study was conducted to evaluate the protein requirement for maintenance of 2-year-old female Korean spotted deer. In the course of the experiment, each of three hand-reared female spotted deer was fed three diets that were iso-calorically formulated to contain low (approximately 7%), medium (12%), and high (17%) levels of crude protein (CP). Each of six trials included a 5-day transition, a 10-day preliminary, and a 7-day collection period. Dietary protein levels affected the apparent digestibility of CP (p<0.05) but not the apparent digestibility of dry matter, organic matter, or acid detergent fiber. All of the deer showed a positive CP balance on all of the diets. The maintenance CP requirement estimated by regression analysis was 4.17 g/kg metabolic body weight $(W^{0.75}){\cdot}d$. The maintenance digestible CP requirement was 1.42 g/kg $W^{0.75}{\cdot}d$. The metabolic fecal CP was 1.95 g/kg $W^{0.75}{\cdot}d$. The blood urea nitrogen of spotted deer increased (p<0.05) as the dietary protein levels increased.

• Journal of Ginseng Research
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• 제20권3호
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• pp.219-225
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• 1996

This study was performed to investigate the inhibition mechanism of cancer cell proof iferation caused by the petroleum-ether extract of ginseng against human rectum (HRT-18), colon (HT-29), llepatoma (Hep G2) and prostate (LNCaP) cancer cells and monkey kidney cells (Vero 76). Cells were treated with the petroleum-ether extract of ginseng (50 to 200 $\mu\textrm{g}$/ml) in G1 or S phase of the cell cycle, and proliferation and protein kinase C activity were measured. The petroleum-eth or extract of ginseng inhibited proliferation of HRT-18, HT-29, Hep G2 and LNCaP when treated in Gl phase, but not in S phase. This result shows that the ginseng extract arrests the cell cycle in G1 phase, resulting in the inhibition of cell proliferation. At the same concentrations, treatment of the ginseng extract in G1 phase decreased protein kinase C activity, while the treatment in S phase had no effect. This reault suggests that protein kinase C might be involved in the inhibition of the cell cycle and proliferation of cancer cells caused by the petroleum-ether extract of ginseng.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.79-79
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• 2001

This study was conducted to measure the total protein, DNA, and RNA contents of corpus luteum(CL) in various stages of estrous cycle and pregnancy. CLs were collected from a local slaughterhouse and stages of the estrous cycle of CL were classified as CL1~2, days 1 to 10; CL3(with/without central cavity), days 11 to 17; CL4, days 18 to 20 by method of Ireland et. al(1980) and stages of the pregnancy of CL were classified as P1~3, months 11~3: P4~6, months 4~6; P7~9, months 7~9 of pregnancy. CL3 with/without central cavity(CC) was identified as described by Kastelic et. al.(1990)-CL with CC, more than 2mm in diameter; CL without CC, less than 2mm in diameter. In total protein content, CL3 with CC was significantly lower than P7~9(p<.05). The total DNA content was lower in CL3 with CC than CL3 without CC and CL4(p<.05). In protein : DNA ratio, CL3 with CC was significantly lower than CL4(p<.05), CL3 without CC was significantly lower than P7~9(p<.05), CL4 was significantly lower than CL3 with CC, P1~3 and P7~9(p<.05). No differences were observed in RNA content, protein:RNA ratio, RNA/DNA of CLs in stages of estrous cycle and pregnancy.

• 한국식품과학회지
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• 제21권3호
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• pp.441-445
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• 1989

인삼엽 단백질의 식량화를 위하여 엽단백질 농축물(LPC)을 조제하여 그 아미노산 조성과 인공소화율을 검토하였다. 인삼엽을 $-20^{\circ}C$ 냉아세톤으로 처리하고 0.2% NaOH(0.5% SDS, 0.5% 2-ME 함유)로 단백질을 추출하며 인삼 LPC를 얻었다. 인삼 LPC의 일반성분으로는 지방과 회분이 1% 미만이었고 단백질은 75% 내외로 많았으며 총 당은 약 5% 이었다. 총 사포닌 함량은 약 1.2%이고 panaxadiol과 panaxatriol의 비는 1.67이었다. 아미노산 조성은 aspartic acid의 함량이 약 13.4%로 가장 많았으며 methionine의 함량은 매우 낮았다. 필수아미노산토 고루 들어 있었고 총 아미노산에 대한 필수아미노산은 54.5%이였고 E/T ratio는 3.02이었다. LPC의 제 1제한아미노산은 함황아미노산이고, 그 amino acid score는 43.1이었다. Pepsin및 trypsin을 사용한 인삼 LPC의 소화율은 비교단백질인 milk casein에 비하며 낮았다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제17권1호
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• pp.1-5
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• 2014

The diagnosis and treatment of cow's milk protein allergy (CMPA) is still a challenge. A systematic literature search was performed using Embase, Medline, The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials for the diagnosis and treatment of cow's milk allergy (CMA). Since none of the symptoms of CMPA is specific and since there is no sensitive diagnostic test (except a challenge test), the diagnosis of CMPA remains difficult. A "symptom-based score" is useful in children with symptoms involving different organ systems. The recommended dietary treatment is an extensive cow milk based hydrolysate. Amino acid based formula is recommended in the most severe cases. However, soy infant formula and hydrolysates from other protein sources (rice) are gaining popularity, as they taste better and are cheaper than the extensive cow's milk based hydrolysates. Recent meta-analyses confirmed the safety of soy and estimate that not more than 10-15% of CMPA-infants become allergic to soy. An accurate diagnosis of CMA is still difficult. The revival of soy and the development of rice hydrolysates challenge the extensive cow's milk based extensive hydrolysates as first option and amino acid formula.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.844-850
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• 2000

The specific binding and internalization of viral particles is an essential step for the successful infection of viral pathogens. In the case of the hepatitis B virus (HBV), virions bind to the host cell via the preS domain of the viral surface antigen and are subsequently internalized by endocytosis. HBV-preS specific receptors are primarily expressed on hepatocytes, however, viral DNA and proteins have also been detected in extrahepatic sites, suggsting that celluar recepators for HBV may also exist on extrahepatic cells. Recently, an EBV-transformed B-cell line was identified onto which the preS region binds in a receptor-ligand specific manner. In this study, this specific interaction was further characterized, and the binding region within the preS protein was locaized. Also the internalization after host cell attachment was visualized and analyzed by fluorescence-labeled HBV-preS1 proteins using confocal microscopy. Energy depletion by sodium azide treatment effectively inhibited the internalization of the membrane-bound preS1 ligands, thereby indicating an energy-dependent receptor-mediated endocytotic pathway. Accordingly, the interaction of HBV-pres! with this specific B-cell line may serve as an effective model for an infection pathway in extrahepatic cells.

• BMB Reports
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• 제44권8호
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• pp.529-534
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• 2011

Ribosomal protein S3 (rpS3) is a multifunctional protein involved in translation, DNA repair, and apoptosis. The relationship between rpS3 and cyclin-dependent kinases (Cdks) involved in cell cycle regulation is not yet known. Here, we show that rpS3 is phosphorylated by Cdk1 in G2/M phase. Co-immunoprecipitation and GST pull-down assays revealed that Cdk1 interacted with rpS3. An in vitro kinase assay showed that Cdk1 phosphorylated rpS3 protein. Phosphorylation of rpS3 increased in nocodazole-arrested mitotic cells; however, treatment with Cdk1 inhibitor or Cdk1 siRNA significantly attenuated this phosphorylation event. The phosphorylation of a mutant form of rpS3, T221A, was significantly reduced compared with wild-type rpS3. Decreased phosphorylation and nuclear accumulation of T221A was much more pronounced in G2/M phase. These results suggest that the phosphorylation of rpS3 by Cdk1 occurs at Thr221 during G2/M phase and, moreover, that this event is important for nuclear accumulation of rpS3.