• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.541-547
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• 1993

A phage clone containing the partial ${\alpha}_{S1}$-casein gene was isolated from a bovine genomic library by using mixed probes of ovine ${\alpha}_{S1}$-, ${\beta}$- and ${\kappa}$-casein cDNAs. Restriction enzyme mapping analysis for 14.6 kb revealed that the map was in conflict with the report of Meade et al. (1990), especially in the 3'-end fragment. Sequence analysis of 12.6 kb revealed a high AT/GC ratio (1.64); we have identified eight exon sequences according to the bovine ${\alpha}_{S1}$-casein cDNA sequence. The same exon/intron splice junction sequence was observed between these exons. We suggest that the bovine ${\alpha}_{S1}$-casein gene night contain a minimum of 18 exons and the full length is approximately 18-19 kb.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.31-36
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• 1991

Yeast expression plasmids containing an appropriate leader sequence and bovine $\beta$-casein cDNA were constructed to produce $\beta$-casein for the study of its functional characteristics. Two kinds of expression systems for $\beta$-casein were constructed using pCGYl444 as a precursor plasmid. This plasmid is a yeast-E. coli shuttle vector which contains the chelatin promoter. The plasmid pISB202 contains the invertase leader sequence and $\beta$-casein gene. The plasmid pDEB303 contains the original bovine $\beta$-casein leader sequence gene. These two plasmids were introduced into S. cerevisiae AB116 which is a strain deficient in the major yeast proteinases. Each clone was grown in minimal media for 24 h before induction by $CuSO_4$. The cells were thus grown under expression conditions. Both strains harbouring pISB202 and pDEB303 expressed bovine $\beta$-casein. The $\beta$-casein was detected using immunochemical staining after western blot. Secretion of $\beta$-casein was detected in the culture broth. The estimated amount of secreted $\beta$-casein was approximately 50 ${\MU}g$/l.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.368-374
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• 2006

We have studied on characterization and cheese making like mineral contents, protein composition and coagulation pattern on equine milk. At first, for contents of mineral on equine milk, It was lower in equine than bovine milk Contents of Na, Mg, P, Ca and K the major minerals, were indicated as 18.3 mg, 0.4 mg, 33.3 mg, 80.9 mg and 134.9 mg respectively by 100 g. In the distribution of nitrogen, the ratio NPN to Nt was indicated as 9.8% while that of bovine milk was 7%. And In NCN, its percentage was indicated as 45.6% shelving that Equine casein was lower than bovine. From these results, equine milk could not be applicable to cheese production since there are no coagulable nitrogen fraction such as ${\kappa}$-casein, as there aye with bovine milk. Equine milk will be more acceptable if we accept that the phylogenic affinity is near to human. It is the same as equine from the view points that monogastric, which did not contain ruminant's casein. For the rennet coagulation, equine milk was different than bovine milk. Equine milk did not coagulated by rennet after the addition of $Ca^{2+}$. But when bovine ${\kappa}$-casein was added in the presece of rennet, and $Ca^{2+}$ to equine milk, coagulation occurred. Such phenomenon was also observed by the use SEM. Verification of ${\kappa}$-casein by SDS-PACE did not existed in equine milk. The Casein of equine milk(54.4%) is similar to human milk in that casein/whey is about 1. For equine milt this can be explained because distance between casein and Ca is great, casein being lower, which result in reaction of casein with $Ca^{2+}$ because it could not activated which lasting time of coagulation is too long.

• Korean Journal of Animal Reproduction
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• v.22 no.3
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• pp.237-244
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• 1998

To investigate the fidelity of transgene transmission and expression, we produced transgenic mice carrying bovine $\beta$-casein/bovine grwoth hormone(bGH) fusion gene and examined transmission efficiency and expression level of the transgene in the founders and their progeny. The transgene was composed of 1.8 kb bovine $\beta$-casein promoter and 2.1 kb bGH gene. Ten transgenic mice were produced. Milk and mammary gland were collected from eight transgenic lines at 10-day lactation and a, pp.ied to Western and Northern blot analyses. The bGH expression was detected in four of them. The concentrations of bGH in milk were highly variable from 4$\mu\textrm{g}$/ml to 600$\mu\textrm{g}$/ml depending on the lines. The bGH mRNA level in mammary gland was closely correlated with the bGH concentration in milk in each transgenic line. These results indicated that bGH transgene expression was a, pp.opriately regulated in the mammary gland and secreted into milk in transgenic mice. By using two transgenic lines(#2, #7) secreting a considerable amoung of bGH into their milk, the inferitance and maintenance of transgenic phenotype were assessed in successive four generations. The mean transmission frequencies of transgene in lines #2 and #7 were 34% and 40%, respectively. The bGH concentration in milk were 80, 240, 120, 60$\mu\textrm{g}$/ml in each G0(generation 0), G2, G3, G4 generation of line #2 and 600, 1600, 860, 900$\mu\textrm{g}$/ml in each G1. G2, G3, G4 generation of line #7. These results demonstrated that bovine $\beta$-casein/bGH gene was stably transmitted from generation to generation in a Menelian fashion in trasgenic mice and consistenly expressed in their milk throughout the generations, although there was a little variation in the transmission frequency and expression level of the transgene between generations.

• Korean Journal of Animal Reproduction
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• v.16 no.2
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• pp.87-102
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• 1992

A rapid, sensitive, and specific enzyme-linked immuno-sorbent assay (ELISA) for bovine casein was developed. Biotinylated casein and peroxidase-conjugated avidin were used in the assay with antibody separated from yolks of immunized hens. Caseins were biotinylated with sulfo-N-hydroxy succinimido biotin and peroxi-dase-conjugated avidin bound the biotinylated casein which became bound to immobilized anti-body on a microplate. The antibodies were specific for bovine $\alpha$- and $\beta$-caseins, and their cross-reactivities with whey proteins, IgG, and serum albumin from bovine were not detectable by ELISA and Western blot. Various sensitivities ranging from 2ng/ml to 20${\mu}\textrm{g}$/ml of casein were achieved, and were controlled by adding vanous concentrations of the biotinylated casein. Parallelism was observed between standard and sample curves. The coefficients of variation of intra-assays and inter-assays from the most sensitive assay were 5.5 and 5.7%, respectively, at the 50% displacement. Casein contents of peripaturient milk samples showed that casein secretion rapidly increased 3d prepartum.

• Reproductive and Developmental Biology
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• v.41 no.3
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• pp.51-55
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• 2017

The production of therapeutic protein from transgenic domestic animal is the major technology of biotechnology. Insulin-like growth factor-1 (IGF-1) is known to play an important role in the growth of the animal. The objective of this study is construction of knock-in vector that bovine IGF-1 gene is inserted into the exon 7 locus of ${\beta}$-casein gene and expressed using the gene regulatory DNA sequence of bovine ${\beta}$-casein gene. The knock-in vector consists of 5' arm region (1.02 kb), bIGF-1 cDNA, CMV-EGFP, and 3' arm region (1.81 kb). To express bIGF-1 gene as transgene, the F2A sequence was fused to the 5' terminal of bIGF-1 gene and inserted into exon 7 of the ${\beta}$-casein gene. As a result, the knock-in vector is confirmed that the amino acids are synthesized without termination from the ${\beta}$-casein exon 7 region to the bIGF-1 gene by DNA sequence. These knock-in vectors may help to create transgenic dairy cattle expressing bovine bIGF-1 protein in the mammary gland via the expression system of the bovine ${\beta}$-casein gene.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.89-89
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• 2003

본 연구에서는 1.7kb 및 3.1kb bovine $\beta$-casein promoter의 유전자 발현 조절능력을 알아보기 위해 1 7kb 및 3.1kb bovine $\beta$-casein promoter에 human Type II Collagen 유전자를 연결해서 DNA microinjection으로 형질전환생쥐를 생산하였다. 총 8마리의 founder생쥐(1.7kb collagen : 5마리, 3.1kb collagen 3마리)를 생산하였고 이 founder생쥐와 wild type 생쥐를 mating시켜서 $F_1 및 F_2$ 새끼를 얻었다. $F_1 및 F_2$새끼들에서 human Type II collagen 유전자의 transmission rate는 약 50%로 Mendel의 법칙에 따라 분리되어 안정적으로 유전자가 염색체에 정착되어 있음을 확인하였다. 이들 $F_1 및 F_2$새끼 중 암컷들을 임신시켜 분만 후 5-10 일경에 유선조직을 포함하여 여러 조직으로부터 RNA를 추출하여 Northern blotting 및 RT-PCR 방법을 이용하여 Type II collagen mRNA의 발현을 분석하였다. 유선에서의 발현은 1 7 kb 및 3.1 kb line별로 각각 1 line씩 발현되지 않았고, 그 외 line에서는 모두 발현되는 것으로 확인되었다. 유선에서의 Type II collagen mRNA 발형양은 1.7 kb 및 3.1 kb bovine $\beta$-casein promoter사이에서는 큰 차이를 나타내지 않았으나 1.7 kb promoter 형질전환생쥐의 경우 유선 이외 조직에서도 발현되는 양상을 나타내었고, 3.1kb promoter line에서는 유선특이적으로 발현시키는 양상을 나타내었다. 그러므로 bovine $\beta$-casein promoter의 1.7 kb와 3.1 kb 사이에 유선특이적 발현을 유도하는 조절부위가 있을 것으로 추정된다.

• KSBB Journal
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• v.5 no.3
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• pp.241-246
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• 1990

ATP analogs were immobilized or bovine caseins by the action of transglutaminase. The ATP analogs immobilized on the caseins were enzymatically active and interconverten by kinases. The immobilized ATP was dephosphorylated to the corresponding ADP by hexokinase and rephosphorylated to the ATP in solid form by acetate kinase. Under the conditions chosen, about 55% of the immobilized ATP was dephosphorylated and about 80% of the resulted ADP was rephosphorylated. Bovine $\beta$-casein was more useful than $\alpha$sf-casein as a carrier and C8-substituted ATP analognwas more effective than N6-substituted one in immobilization. Michaelis constant of C8-substituted ATP analog immobilized on $\beta$-casein was similar to that of free form of ATP and that of ATP analog. The immobilized ATP was much more stable than free ATP and its analog, while maximum velocity was reduced to 37% of the free ATP analog. The immobilized ATP was recovered almost completely by calcium precipitation.

• Journal of Dairy Science and Biotechnology
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• v.25 no.2
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• pp.11-16
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• 2007

The nomenclature of genetic variants of casein which is major protein in milk have had a lot of confusion, but now have established. Genetic variants of ${\alpha}_{s1}-CN,\;{\alpha}_{s2}-CN,\;{\beta}-CN,\;{\kappa}-CN$ have reported 8 variants(A, B, C, D, E, F, G, H), 4 variants(A, B, C, D), 13 variants ($A_1,\;A_2,\;A_3,\;A_4$, B, C, D, E, F, G, $H_1,\;H_2$, I), 11 variants(A, B, C, E, $F_1,\;F_2,\;G_1,\;G_2$, H, I, J), respectively. Their data detailed have introduced in several web sites including www.uniprot.org. The studies on genetic variants of casein from Korean native cattle have been reported only ${\beta}-casein\;A_4$ but still not established the protein sequence. The classification and distinct nomenclature of genetic variants of bovine casein were required because the development of milk science and technology have been focused in the region that have to studied biochemically such as functional foods, EMC and GMO et al.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.274-280
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• 2002

This study was conducted to investigate inhibitory effects of K-casein, GMP and sialic acid addition on the infection of MA-104 cells by 597(Korean native cattle rotavirus) and JBR(Jeju island bovine rotavirus). MA-104 cells on incomplete Ml99 were infected with domestically separated 597 and ma activated by incubating at 37$\^{C}$ for 6 days, and analyzed for the titer of rotavirus. K-casein, GMP and sialic acid added MA-104 culture infected by activated S97 and nan were incubated for Is hours and stained by the AEC stainning method. The number of infected cells were counted on microscope. The titer of S97 and JBR was 2.5$\times$107 and 2.0$\times$106 PFU/ml, respectively. The inhibition level against cell infection by 597 was 97.4% far 2000UH of K-casein and 97.44% for 2000UM of GMP. The inhibition level against cell infection by JBR was 99.52% for 2000$\mu$M of $\kappa$-casein and 99.78% for 2000$\mu$M of GMP. The inhibition level against cell infection by 597 and JBR was 3.85 and 3.63% for 2000$\mu$M of sialic acid, respectively. The high inhibitory effects (over 97%) of K-casein and CMP against infection of U-1(14 cells with 597 and mR indicated great potentials for the use of K-casein and GMP in the treatment of calf or infant caused by rotavirus.