• 한국식품과학회지
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• 제21권1호
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• pp.164-172
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• 1989

Streptococcus thermophilus 510의 ${\beta}-galactosidase$는 유당을 가수분해 하는 동시에 galactose전이반응을 일으켜 세 종류의 galactooligosaccharides를 형성 하였다. Oligosaccharide의 최대 생성 조건은 40% 유당 용액에 효소 50 ONPG units/ml를 첨가한 혼합액을 $37^{\circ}C$에서 4시간 반응시켰을 때 이며, 이 조건에서 유당이 약 94% 가수분해 되었고 생성된 oligosaccharides의 양은 총 당의 약 30% 이었다. 생성된 총 oligosaccharides의 69%는 $6-o-{\beta}-D-galactopyranosyl-D-glucose(allolactose)$, 23%는 $6-o-{\beta}-D-galactopyranosyl-D-galactose(isogalactobiose)$ 이었으며, 형성된 galactooligosaccharides을 Bio-Gel P-2 gel permeation chromatography 방법에 의해서 순수하게 분리 정제하여 구조를 조사하여 본 결과 glucose, galactose, allolactose, 그리고 isogalactobiose 임을 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1124-1131
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• 2020

Techniques used for the regulation of gene expression facilitate studies of gene function and treatment of diseases via gene therapy. Many tools have been developed for the regulation of gene expression in mammalian cells. The Lac operon system induced with isopropyl β-D-1-thiogalactopyranoside (IPTG) is one of the employed inducible systems. IPTG mimics the molecular structure of allolactose and has a strong affinity for the corresponding repressor. IPTG is known to rapidly penetrate into mammalian cells and exhibits low toxicity. In the present study, we developed a new inducible expression system that could regulate the expression of genes in mammalian cells using IPTG. Here we confirm that unlike other vector systems based on the Lac operon, this expression system allows regulation of gene expression with lactose in the mammalian cells upon transfection. The co-treatment with IPTG and lactose could improve the regulatory efficiency of the specific target gene expression. The regulation of gene expression with lactose has several benefits. Lactose is safe in humans as compared to other chemical substances and is easily available, making this technique very cost-effective.