• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.393-395
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• 1992

The ${\alpha}-lactalbumin({\alpha}-la)$ concentration in raw and laboratory-heated milks by HPLC was 1.20 mg/ml (unheated), 1.17 mg/ml ($63^{\circ}C$, 30min), 1.13 mg/ml ($72^{\circ}C$, 15sec) and 0 mg/ml ($100^{\circ}C$, 10min), respectively. Whereas, ${\alpha}-lactalbumin$ concentration ranges of commercial milks were $1.00{\sim}1.02\;mg/ml$ (pasteurized), $0.23{\sim}0.68\;mg/ml$ (UHT-pasteurized) and $0.77{\sim}0.89\;mg/ml$ (UHT-sterilized), respectively. It was supposed that the ${\alpha}-lactalbumin$ content of sterilized milk will be lower than that of UHT milk, but the opposite occurred. This discrepancy would be caused by the different heating system in the milk plants, where indirect UHT-treatment had more heat intensity than direct UHT-processing. The HPLC determination of ${\alpha}-lactalbumin$ may be an indicator to evaluate correctly and rapidly heated milks.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.1-2
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• 2000

High production of milk and its components are necessary to allow maximal growth of developing piglets. In this study, transgenic pigs were produced containing the $\alpha$-lactalbumin gene, whose product is a potential limiting component in the production of milk. Two lines of transgenic pigs were produced to analyze the effects that overproduction of the milk protein $\alpha$-lactalbumin may have on milk production and piglet growth. Transgenic pigs were produced through microinjection of the bovine $\alpha$-lactalbumin gene. The gene construct contained 2.0 kb of 5 flanking region, the 2.0 kb coding region and 329 bp of 3 flanking region. Sows hemizygous for the transgene produced as much as 0.9 g of bovine $\alpha$-lactalbumin per liter of pig milk. The production of the bovine protein caused approximately a 50 % increase in the total $\alpha$-lactalbumin concentration in pig milk throughout lactation. The concentration of bovine $\alpha$-lactalbumin was highest on day 0 and 5 of lactation and decreased as lactation progressed. The ratio of bovine to porcine $\alpha$-lactalbumin changed during the sow's lactation. This ratio was 4.3 to 1 on day 0 of lactation, but by day 20 of lactation the ratio was 0.43 to 1. This suggested that the bovine transgene and the endogenous porcine gene were under slightly different control mechanisms. The higher level of total $\alpha$-lactalbumin present on day 0 of lactation was correlated with higher lactose percentage on day 0 in transgenic sows (3.8 %) as compared to controls (2.6 %) (P < 0.01). Although there was also a trend for higher lactose percentage in transgenic sows on day 5 and 10 of lactation, no significant differences were observed. These data suggest that $\alpha$-lactalbumin is limiting early in lactation of swine. Furthermore, higher concentrations of $\alpha$-lactalbumin early in lactation may boost milk output.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.321-333
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• 2000

High production of milk and its components are necessary to allow maximal growth of developing piglets. In this study, transgenic pigs were produced containing the $\alpha$ -lactalbumin gene, whose product is a potential limiting component in the production of milk. Two lines of transgenic pigs were produced to analyze the effects that overproduction of the milk protein $\alpha$ -lactalbumin may have on milk production and piglet growth. Transgenic pigs were produced through microinjection of the bovine $\alpha$ -lactalbumin gene. The gene construct contained 2.0 kb of 5'flanking region, the 2.0 kb coding region and 329 bp of 3'flanking region. Sows hemizygous for the trans gene produced as much as 0.9 g of bovine $\alpha$-lactalbumin per liter of pig milk. The production of the bovine protein caused approximately a 50% increase in the total $\alpha$ -lactalbumin concentration in pig milk throughout lactation. The concentration of bovine $\alpha$ -lactalbumin was highest on day 0 and 5 of lactation and decreased as lactation progressed. The ratio of bovine to porcine $\alpha$ -lactalbumin changed during the sow's lactation. This ratio was 4.3 to 1 on day 0 of lactation, but by day 20 of lactation the ratio was 0.43 to 1. This suggested that the bovine transgene and the endogenous porcine gene were under slightly different control mechanisms. The higher level of total $\alpha$-lactalbumin present on day 0 of lactation was correlated with higher lactose percentage on day 0 in transgenic sows (3.8%) as compared to controls (2.6%) (P＜0.01). Although there was also a trend for higher lactose percentage in transgenic sows on day 5 and 10 of lactation, no significant differences were observed. These data suggest that $\alpha$ -lactalbumin is limiting early in lactation of swine. Furthermore, higher concentrations of $\alpha$ -lactalbumin early in lactation may boost milk output.

• KSBB Journal
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• v.16 no.6
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• pp.533-537
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• 2001

${\alpha}$-lactalbumin and ${\beta}$-lactoglobulin in whey proteins were separated by high performance membrane chromatography (HPMC). The separation mechanism involved anion-exchange, and the stationary phase was anion CIM (Convective Interaction Media) DEAE, QA disk and cation exchanger SO$_3$(16${\times}$3 mm). Two types of mobile phase were used, buffer A (20 mM Tris-HCI, pH 7.3) and buffer B(buffer A + 1 M NaCl), As the amount of NaCl dissolved in buffer linearly increased, which enabled a gradient elution mode. The optimum mobile phase and operating condition (Buffer A/Buffer B = 100/0 - 30/70 vol%, gradient time 1 min, 30/70 - 10/90 vol.%, gradient time 2 min) were experimentally determined. In this experimental condition, ${\alpha}$-lacta1bumin, ${\beta}$-lactoglobulin were separated within 5 min at a mobile phase flow rate of 4 mL/min.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.179-182
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• 2004

This study reports the extraction behavior of $\alpha$-lactalbumin using bis(2-ethylhexyl) sulfosuccinate sodium (AOT) reverse micelles. Forward extraction of $\alpha$-lactalbumin in the reverse micellar organic phase from aqueous feed solutions was strongly dependent on the AOT concentration and the complete forward extraction of 0.03 mM $\alpha$-lactalbumin was successfully achieved at an AOT concentration of ca. 100 mM. A similar dependency of the forward extraction on the AOT concentration was obtained in isooctane, n-hexane, and n-octane systems. In the backward extraction from the micellar organic phase, the recovery of the protein as high as ca. 90% was obtained with pH control and/or salt addition.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.145-148
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• 2001

The interaction between tetradecyl trimethyl ammonium bromide (TTAB) with bovine ${\alpha}-lactalbumin$ has been investigated at pH = 9 and at $37^{\circ}C$ by isothermal titration calorimetry, equilibrium dialysis and UV-Vis spectrophotometry methods. The binding data from unusual Scatchard plot have been analyzed in terms of the Hill equation for three sets of binding sites. The calorimetric data show that TTAB interacts endothermically with ${\alpha}-lactalbumin$ and causes protein unfolding below 2 mM concentration of TTAB, which is confirmed by spectrophotometric data. The unfolding of the protein would be mainly due to occupation of the second set of binding sites.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.48-51
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• 2002

In order to study the reaction behavior of bovine holo- and apo-$\alpha$-lactalbumin ($\alpha$-La) during heat treatment at 65~10$0^{\circ}C$, the samples were analysed by first (ID)-and second-dimensional (2D) native-polyacrylamide gel electrophoresis (Native-PAGE) and sodium dodecylsulfate (SDS)-PAGE. When bolo-$\alpha$-La or apo- $\alpha$ -La were heated, they formed non-native, monomers, dimers and trimers. The apo-$\alpha$-La was more heat-sensitive than holo-$\alpha$-La. The monomers seemed to have the same composition as the native $\alpha$-La, but many of the disulfide bonds could be non-native.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.72-76
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• 2002

Bovine serum albumin(BSA), $\alpha$-lactalbumin($\alpha$-LA), $\beta$-lactoglobulin($\beta$-LG) and bovine immunoglobulin G (IgG) were investigated the cytotoxicity on tumor cell lines. $\alpha$-LA was showned a tendency of dose dependaent on cytotoxicity using WiDr. The growth of WiDr was inhibited 82% by 1mg/ml of $\alpha$-LA. However, IgG, BSA and $\beta$-LG were not shown the cytotoxicity on WiDr. When $\alpha$-LA was purified by using high pressure liquid chromatography(HPLC), the main component($\alpha$-LA) was eluted at 33.057 min and extremely small quantities eluted at 32.310 min. The cytotoxicity of main component (eluted at 33.057 min peak) was lower than commercial $\alpha$-LA. And the cytotoxic activity of hydrolyzed $\alpha$-LA and $\alpha$-LA treated with EDTA were lower than commercial $\alpha$-LA on tumor cells.

• Food Science of Animal Resources
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• v.18 no.1
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• pp.9-18
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• 1998

This study was performed to obtain a large quantity of $\alpha$-lactalbumin ($\alpha$-LA) from milk by an improved separation and purification method. Functional properties-solubility viscosity, emulsifying activity, foamability surface hydrophobicity and gelation-of the purified $\alpha$-LA were investigated, $\alpha$-LA was purified in a large quantity by DEAE-Sephacel chromatography using 0.15M NaCl in 20mM Tris-HCl buffer(pH 7.2), as an eluent. The yield and purity of the purified $\alpha$-LA were 23.6%, 92.5%, respect-ively. The solubility viscosity and emulsifying activity of the purified $\alpha$-LA were 92.2$\pm$2% 3.46$\pm$0.19 cP and 345$\pm$5.0m^2$-/g respecively. The foamability of $\alpha$ -LA was 762 after 5min whipping which was lower than that of WPC and showed decreasing tendency with whipping time. The relative surface hydrophobicity of the $\alpha$-LA was formed when a 10% $\alpha$-LA solution containing 100mM NaCl and 20 mM $CaCl_2$ was heated at 92$^{\circ}C$for 40min. The $\alpha$-LA gel showed 31.5 as hardness and showed low springiness and cohesiveness.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.561-568
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• 2012

The aim of this study was to introduce a simple method for isolation of ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin from cow's milk, and peptides produced by enzymatic hydrolysis of ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin with alcalase. Whey protein were precipitated from whey by ammonium sulfate and, ${\alpha}$-lactalbumin and ${\beta}$-lactoglobulin were isolated using Hi Prep 26/60 Sephacryl S-100 column gel filtration chromatography. Bovine serum albumin and ${\beta}$-lactoglobulin were isolated by Mono-Q 5/50 GL column anion exchange chromatography of the 50% Ammonium Sulfate-supernatant. Isolated whey proteins were hydrolyzed by proteolytic alcalase. Tricine SDS-PAGE and reverse-phase HPLC analyses revealed that almost hydrolyzed all the ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin with alcalase. Molecular weight of various peptides derived from alcalase hydrolysate were small molecular weight than 3.5 kDa.