School of Biotechnology, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
J Agric Food Chem. 2012 Mar 28;60(12):3253-9. doi: 10.1021/jf204538m. Epub 2012 Mar 19.
Glycosylated α-galactosidase (melibiase) has been purified from white chickpea ( Cicer arietinum ) to 340-fold with a specific activity of 61 units/mg. Cicer α-galactosidase showed a M(r) of 45 kDa on SDS-PAGE and by MALDI-TOF. The optimum pH and temperature with pNPGal were 4.5 and 50 °C, respectively. The K(m) for hydrolysis of pNPGal was 0.70 mM. Besides hydrolyzing the pNPGal, Cicer α-galactosidase also hydrolyzed natural substrates such as melibiose, raffinose, and stachyose very effectively; hence, it can be exploited commercially for improving the nutritional value of soy milk. Galactose was found to be a competitive inhibitor. The property of this enzyme to cleave the terminal galactose residues can be utilized for converting the group B erythrocytes to group O erythrocytes.
已从白芸豆（Cicer arietinum）中纯化出糖基化的α-半乳糖苷酶（蜜二糖酶），其比活为 61 单位/毫克，达到 340 倍。Cicer α-半乳糖苷酶在 SDS-PAGE 和 MALDI-TOF 上的 M(r)为 45 kDa。在 pNPGal 作用下，最适 pH 和温度分别为 4.5 和 50°C。水解 pNPGal 的 K(m)为 0.70 mM。Cicer α-半乳糖苷酶除了水解 pNPGal 外，还能有效地水解天然底物，如蜜二糖、棉子糖和水苏糖，因此可用于商业上提高豆浆的营养价值。发现半乳糖是一种竞争性抑制剂。该酶切割末端半乳糖残基的特性可用于将 B 型红细胞转化为 O 型红细胞。
