lactose

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: lactose
• 化学式: C₁₂H₂₂O₁₁
• 分子量: 342.3
• InChiKey: DKXNBNKWCZZMJT-IHCGBPIYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -5.55
• 重原子数：
  23.0
• 可旋转键数：
  8.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.92
• 拓扑面积：
  197.37
• 氢给体数：
  8.0
• 氢受体数：
  11.0

反应信息

• 作为反应物：
  描述：

  lactose 、 苯甲醇 在 Kluyveromyces lactis β-galactosidase 作用下， 以 水 为溶剂， 反应 24.0h， 生成 苄基Beta-D-吡喃半乳糖苷
  参考文献：
  名称：

  Synthesis of benzyl β-d-galactopyranoside by transgalactosylation using a β-galactosidase produced by the over expression of the Kluyveromyces lactis LAC4 gene in Arxula adeninivorans

  摘要：

  The LAC4 gene of Kluyveromyces lactis encoding for beta-galactosidase was overexpressed in the yeast Arxula adeninivorans to produce the enzyme, which can be used for the synthesis of beta-D-galactosides. These compounds play a major role as precursors for the synthesis of glycolipids and glycoproteins in medicine or for the production of tensides.The Xplor (R) 2 transformation/expression platform was used because it enabled stable integration of the gene in the Arxula genome and the production of high levels of the enzyme. The recombinant beta-galactosidase, fused with C-terminal His-tag region (Lac4-6hp), was purified by precipitation with ammonium sulphate and FPLC using hydroxylapatite. The enzyme exhibited optimal activity at 37 to 40 degrees C, pH 6.5 in 50 mM sodium acetate buffer. Activity was measured by the formation of p-nitrophenol at 405 nm from the hydrolyzed chromogenic substrate, p-nitrophenyl-beta-D-gal. Biochemical characterization included the calculation of K-M and apparent k(cat) values of the enzyme. The formation of benzyl beta-D-gal by 0.1 U enzyme from A. adeninivorans with transgalactosylation was six times higher than that for the prokaryotic enzyme from E. coli. Moreover, the partially purified enzyme was used for the selective hydrolysis of allyl beta-D-gal in a mixture of allyl beta- and allyl alpha-D-gal, with 4 gl(-1) being hydrolysed within one day by 1 U ml(-1). Thus, the recombinant beta-galactosidase produced in A. adeninivorans is of potential interest for the enzymatic synthesis of benzyl beta-D-gal and other galactosides as well as the selective hydrolysis of anomeric mixtures and could be used to replace difficult chemical procedures. (C) 2013 Elsevier B.V. All rights reserved.

  DOI：

  10.1016/j.molcatb.2013.06.017

文献信息

• Synthesis of benzyl β-d-galactopyranoside by transgalactosylation using a β-galactosidase produced by the over expression of the Kluyveromyces lactis LAC4 gene in Arxula adeninivorans
  作者：Marion Rauter、Maria Schwarz、Karin Becker、Keith Baronian、Rüdiger Bode、Gotthard Kunze、H.-Matthias Vorbrodt

  DOI：10.1016/j.molcatb.2013.06.017

  日期：2013.12

  The LAC4 gene of Kluyveromyces lactis encoding for beta-galactosidase was overexpressed in the yeast Arxula adeninivorans to produce the enzyme, which can be used for the synthesis of beta-D-galactosides. These compounds play a major role as precursors for the synthesis of glycolipids and glycoproteins in medicine or for the production of tensides.The Xplor (R) 2 transformation/expression platform was used because it enabled stable integration of the gene in the Arxula genome and the production of high levels of the enzyme. The recombinant beta-galactosidase, fused with C-terminal His-tag region (Lac4-6hp), was purified by precipitation with ammonium sulphate and FPLC using hydroxylapatite. The enzyme exhibited optimal activity at 37 to 40 degrees C, pH 6.5 in 50 mM sodium acetate buffer. Activity was measured by the formation of p-nitrophenol at 405 nm from the hydrolyzed chromogenic substrate, p-nitrophenyl-beta-D-gal. Biochemical characterization included the calculation of K-M and apparent k(cat) values of the enzyme. The formation of benzyl beta-D-gal by 0.1 U enzyme from A. adeninivorans with transgalactosylation was six times higher than that for the prokaryotic enzyme from E. coli. Moreover, the partially purified enzyme was used for the selective hydrolysis of allyl beta-D-gal in a mixture of allyl beta- and allyl alpha-D-gal, with 4 gl(-1) being hydrolysed within one day by 1 U ml(-1). Thus, the recombinant beta-galactosidase produced in A. adeninivorans is of potential interest for the enzymatic synthesis of benzyl beta-D-gal and other galactosides as well as the selective hydrolysis of anomeric mixtures and could be used to replace difficult chemical procedures. (C) 2013 Elsevier B.V. All rights reserved.