• Asian-Australasian Journal of Animal Sciences
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• 제14권11호
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• pp.1628-1633
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• 2001

A goat ${\beta}$-casein gene was cloned and sequenced. Our previous study had determined the nucleotide sequences of the 5' flanking region and the structural gene including all 9 exons. In the present study, investigations were done on the regulatory sequences in the 5' flanking region of the goat ${\beta}$-casein gene by aligning and comparing it with the same gene from other mammals. The results showed that -200/-1 bp of the 5' flanking sequences contained six conserved clusters, in which the sites of gene expression regulated by the transcription factor and hormone might exist. It showed that fourteen glucocorticoid receptor elements, two cAMP responsive elements, two SV40 virus enhancer core sequences, two OCT-1 binding elements and one CTF/NF-1 binding element were dispersed in the 5' flanking region of goat ${\beta}$-casein gene. Our findings are perhaps valuable for the elucidation of the molecular mechanisms that control the expression of the goat ${\beta}$-casein gene.

• 농업과학연구
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• 제29권2호
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• pp.43-52
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• 2002

본 연구는 한국 재래 산양 112두와 유산양인 Saanen종 7두의 혈액으로부터 genomic DNA를 추출하고, PCR-RFLP 방법에 의해 $\beta$-casein 유전자의 특성을 분석하여 한국재래산양의 효율적인 유전자원의 보존 및 개량을 위한 기초 자료로 제공하고자 실시하였다. 한국재래산양의 genomic DNA로부터 PCR기법을 이용하여 $\beta$-casein의 유전자좌를 증폭한 결과 각각 481bp 크기의 단편이 양호하게 증폭되었음을 확인하였다. $\beta$-casein 유전자 좌의 증폭산물에 대한 Bal I의 제한효소를 처리한 결과, $\beta$-casein AB형은 481bp, 284bp 및 197bp의 단편을, 그리고 BB형은 284bp와 197bp의 단편을 한국재래산양과 유산양인 Saanen 종에서 확인 할 수 있었다. 유전자형 빈도에 있어서는 한국재래산양에서 $\beta$-casein AB 및 BB의 빈도는 각각 6.25 및 93.75%이었고, 유산양인 Saanen 종은 각각 57.14 및 42.86%이었다. 유전자빈도에 있어서는 한국재래산양의 $\beta$-casein A 및 B의 빈도가 각각 0.031 및 0.969이었고, Saanen 종에서는 각각 0.286 및 0.714의 빈도를 보였다. 한국재래산양의 $\beta$-casein 유전자의 염기서열과 이미 보고되어 있는 goat의 염기서열(GeneBank accession Number M90556)간에는 총 11개의 염기서열에 차이를 나타내어 97.71%의 상동성을 보였다. 따라서 한국재래산양의 $\beta$-casein 유전자의 다형성과 염기서열 분석에 의한 분자유전학적 특성의 규명은 한국재래산양의 유전자원의 보존 및 개량을 위한 기초 및 응용 자료로 이용될 수 있을 것으로 생각된다.

• 한국축산식품학회지
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• 제25권2호
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• pp.238-243
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• 2005

산양유 $\beta-casein$의 효소에 의한 가수분해 특성과 가수분해물의 ACE 저해 효과를 측정하고자 산양유의 $\beta-casein$을 양이온 교환 컬럼인 Mono S HR 5/5를 이용하여 분리하였으며 분리된 $\beta-casein$을 동물성 분해효소인 trypsin으로 처리하여 가수분해 특성을 확인하였고 가수분해물의 ACE 저해활성을 측정하였다. Mono S HR 5/5 양이온 교환 컬럼을 이용한 산양유 산 케이신으로 부터 순수한 $\beta-casein$의 분리는 SDS-PAGE를 이용하여 확인한 결과 순수한 $\beta-casein$의 분리가 이루어졌음을 확인할 수 있었다. $\beta-casein$을 $37^{\circ}C4$에서 trypsin으로 처리하여 전기영동으로 확인한 결과 가수분해 직후부터 $\beta-casein$ 위치의 band가 희미해지기 시작하고 저분자량의 band가 나타나기 시작하였으나 120분이 지난 후에는 모든 band가 가수분해되어 사라졌고 산양유에서 분리된 $\beta-casein$을 trypsin으로 처리하여 120분 경과 후 그 가수분해물을 이용하여 ACE 저해효과를 측정한 결과 가수분해하지 않은 $\beta-casein$은 $1.80\pm1.21\%$의 ACE 저해활성을 보였으나 trypsin으로 가수분해하여 ACE 저해 활성을 측정하였을 때 $25.36\pm0.79\%$의 저해 활성을 나타내었으며, trypsin에 의한 $\beta-casein$가수분해물의 $IC_{50}$을 측정한 결과 $308.7\pm2.77({\mu}g/mL)$로 나타났다.

• 한국축산식품학회지
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• 제37권6호
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• pp.940-947
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• 2017

Goat milk has a protein composition similar to that of breast milk and contains abundant nutrients, but its use in functional foods is rather limited in comparison to milk from other sources. The aim of this study was to prepare a goat A2 ${\beta}$-casein fraction with improved digestibility and hypoallergenic properties. We investigated the optimal conditions for the separation of A2 ${\beta}$-casein fraction from goat milk by pH adjustment to pH 4.4 and treating the casein suspension with calcium chloride (0.05 M for 1 h at $25^{\circ}C$). Selective reduction of ${\beta}$- lactoglobulin and ${\alpha}_s$-casein was confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. The hypoallergenic property of A2 ${\beta}$-casein fraction was examined by measuring the release of histamine and tumor necrosis factor alpha from HMC-1 human mast cells exposed to different proteins, including A2 ${\beta}$-casein fraction. There was no significant difference in levels of both indicators between A2 ${\beta}$-casein treatment and the control (no protein treatment). The A2 ${\beta}$-casein fraction is abundant in essential amino acids, especially, branched-chain amino acids (leucine, valine, and isoleucine). The physicochemical properties of A2 ${\beta}$-casein fraction, including protein solubility and viscosity, are similar to those of bovine whole casein which is widely used as a protein source in various foods. Therefore, the goat A2 ${\beta}$-casein fraction may be useful as a food material with good digestibility and hypoallergenic properties for infants, the elderly, and people with metabolic disorders.

• 한국발생생물학회지:발생과생식
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• 제13권3호
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• pp.191-198
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• 2009

In an attempt to simultaneously produce two human proteins, hGH and hG-CSF, in the milk of transgenic mice, we constructed goat $\beta$-casein-directed hGH and hG-CSF expression cassettes individually and generated transgenic mice by co-injecting them into mouse zygotes. Out of 33 transgenic mice, 29 were identified as double transgenic harboring both transgenes on their genome. All analyzed double transgenic females secreted both hGH and hG-CSF in their milks. Concentrations ranged from 2.1 to $12.4\;mg/m{\ell}$ for hGH and from 0.04 to $0.13\;mg/m{\ell}$ for hG-CSF. hG-CSF level was much lower than hGH level but very similar to that of single hG-CSF mice, which were introduced with hG-CSF cassette alone. In order to address the causes of concentration difference between hGH and hG-CSF in milk, we examined mRNA level of hGH and hG-CSF in the mammary glands of double transgenic mice and tissue specificity of hG-CSF mRNA expression in both double and single transgenic mice. Likewise protein levels in milk, hGH mRNA level was much higher than hG-CSF mRNA, and hG-CSF mRNA expression was definitely specific to the mammary glands of both double and single transgenic mice. These results demonstrated that two transgenes have distinct transcriptional potentials without interaction each other in double transgenic mice although two transgenes co-integrated into same genomic sites and their expressions were directed by the same goat $\beta$-casein promoter. Therefore goat $\beta$-casein promoter is very useful for the multiple production of human proteins in the milk of transgenic animals.

• Journal of Dairy Science and Biotechnology
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• 제34권3호
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• pp.173-180
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• 2016

In many countries, goat milk is an excellent nutrient source and is less allergenic for children and the elderly. The casein composition of goat milk consists largely of ${\beta}$-casein and lower amounts of ${\alpha}_{s1}$-casein, which may interfere with digestion by forming solid curds in the human stomach. Goat milk contains small fat globules and large amounts of medium chain fatty acids for, better digestibility, as well as abundant minerals and vitamins with high absorption rates. Recently, the medical benefits of goat milk in different human disorders have been recognized, leading to an increased interest in developing functional foods with goat milk, particularly for individuals with malabsorption syndrome. However, the physiological and biochemical properties of goat milk are largely unknown. We review the importance of goat milk as a potential functional food by providing scientific evidence confirming its health benefits.

• Reproductive and Developmental Biology
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• 제30권4호
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• pp.293-299
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• 2006

In order to generate transgenic goats expressing human growth hormone (hGH) in their mammary glands, goat ${\beta}-Casein/hGH$ hybrid gene was introduced into goat zygotes by pronuclear microinjection. DNA-injected embryos were transferred to the oviduct of recipients at 2-cell stage or to the uterus at morula/blastocyst stage after cultivation in glutathione-supplemented mSOF medium in vitro. Pregnancy and survival rate were not significantly different between 2-cell embryos and morula/blastocysts transferred to oviduct and uterus, respectively. One transgenic female goat was generated from 153 embryos survived from DNA injection. Southern blot analysis revealed that the transgenic goat harbored single-copy transgene with a partial deletion in its sequences. Despite of the partial sequence deletion, the transgene was successfully expressed hGH at the level of $72.1{\pm}15.1{\mu}g/ml$ in milk throughout lactation period, suggesting that the sequence deletion had occurred in non-essential part of the transgene for the transgene expression. Unfortunately, however, the transgene was not transmitted to her offspring during three successive breeding seasons. These results demonstrated that goat ${\beta}-casein/hGH$ gene was integrated into the transgenic goat genome in a mosaic fashion with a partial sequence deletion, which could result in a low level expression of hGH and a failure of transgene transmission.

• Asian-Australasian Journal of Animal Sciences
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• 제25권3호
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• pp.421-427
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• 2012

The production of therapeutic proteins from transgenic animals is one of the most important successes of animal biotechnology. Milk is presently the most mature system for production of therapeutic proteins from a transgenic animal. Specifically, ${\beta}$-casein is a major component of cow, goat and sheep milk, and its promoter has been used to regulate the expression of transgenic genes in the mammary gland of transgenic animals. Here, we cloned the porcine ${\beta}$-casein gene and analyzed the transcriptional activity of the promoter and intron 1 region of the porcine ${\beta}$-casein gene. Sequence inspection of the 5'-flanking region revealed potential DNA elements including SRY, CdxA, AML-a, GATA-3, GATA-1 and C/EBP ${\beta}$. In addition, the first intron of the porcine ${\beta}$-casein gene contained the transcriptional enhancers Oct-1, SRY, YY1, C/EBP ${\beta}$, and AP-1, as well as the retroviral TATA box. We estimated the transcriptional activity for the 5'-proximal region with or without intron 1 of the porcine ${\beta}$-casein gene in HC11 cells stimulated with lactogenic hormones. High transcriptional activity was obtained for the 5'-proximal region with intron 1 of the porcine ${\beta}$-casein gene. The ${\beta}$-casein gene containing the mutant TATA box (CATAAAA) was also cloned from another individual pig. Promoter activity of the luciferase vector containing the mutant TATA box was weaker than the same vector containing the normal TATA box. Taken together, these findings suggest that the transcription of porcine ${\beta}$-casein gene is regulated by lactogenic hormone via intron 1 and promoter containing a mutant TATA box (CATAAAA) has poor porcine ${\beta}$-casein gene activity.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.743-749
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• 2004

The gene encoding human serum albumin (HSA) was cloned from human liver cDNA library by PCR. The HSA cDNA in size of 2,176 bp, including 1,830 bp of open reading frame, was cloned into the plasmid carried with the 5'flanking sequence of goat $\beta$-casein gene (-4,044 to +2,025 bp) to get a tissue specific expression vector in mammary gland named pGB562/HSA (12.5 kb). A 9.6 kb DNA fragment in which the sequence is in order of goat $\beta$-casein gene regulatory sequence, HSA cDNA and SV40 polyadenylation signals was isolated from the pGB562/HSA by SacI and DraIII cutting, and used to microinject into the pronuclei of mouse fertilized eggs to produce transgenic mice. Three transgenic mice (2 female and 1 male) were identified by PCR and dot Southern blot analysis. The copy numbers of integrated transgene were more than 10 copies in line #21 and #26 as well as over 50 copies in line #31 of transgenic mice. HSA protein collected from the milk of lactating transgenic mice was confirmed by immuno-detection of Western and slot blot. The concentrations of HSA in the milk were from 0.05 to 0.4 mg/ml. An obvious antigen and antibody conjugate could be observed in immunohistochemical stain of mammary gland tissue from lactating day 11 of HSA transgenic mice. The transmission of transgene and its expression was recognized according to the results of RT-PCR and sequences analyses of their progeny.

• Journal of Dairy Science and Biotechnology
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• 제35권2호
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• pp.105-111
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• 2017

젖소, 한우, 돼지, 그리고 산양의 초유 중 단백질의 변화를 초일부터 7일까지 조사하였다. 돼지의 초유를 제외한 젖소, 한우, 그리고 산양의 초유에서 면역글로불린, 락토페린, 락토퍼옥시데이스, 혈청 알부민, IgG heavy chain, 그리고 IgG light chain은 분만 후, 초일 함량이 현저히 높았고, 2일째부터 급격히 감소하는 것을 보여 주었다. 그리고 ${\alpha}_{S2}$-카세인, ${\alpha}_{S1}$-카세인, ${\beta}$-카세인, ${\kappa}$-카세인, ${\beta}$-락토글로불린 및 ${\alpha}$-락트알부민은 분만 직후부터 7일까지 현저한 함량의 차이는 나타나지 않았다. 한편, 돼지 초유의 경우는 모든 단백질이 분만 후, 초일부터 2일까지 높은 함량을 나타내었다.