产品内容
本酶催化的反应为beta-D-Gal-(1->3)-beta-D-GlcNAc-(1->3)-beta-D-Gal-(1->4)-D-Glc + H2O = beta-D-Gal-(1->3)-D-GlcNAc + beta-D-Gal-(1->4)-D-Glc,系统名称为Oligosaccharide Lacto-N-Biosylhydrolase,来自链霉菌(Streptomyces)的酶特异性水解结构为 β-D-Gal-(1→3)-β-D-GlcNAc-(1→3)-β-D-Gal-(1→R) 的寡糖非还原端的末端乳糖-N-二糖基残基(β-D-Gal-(1→3)-D-GlcNAc)。乳糖-N-六糖(β-D-Gal-(1→3)-β-D-GlcNAc-(1→3)-β-D-Gal-(1→3)-β-D-GlcNAc-(1→3)-β-D-Gal-(1→4)-D-Glc)被水解,首先形成乳糖-N-四糖加乳糖-N-二糖,随后形成乳糖。非还原末端 Gal 或倒数第二个 GlcNAc 被岩藻糖或唾液酸取代的寡糖不是底物。去唾液酸 GM1 四糖(β-D-Gal-(1→3)-β-D-GalNAc-(1→3)-β-D-Gal-(1→4)-D-Glc)被非常缓慢地水解,但乳糖-N-新四糖(β-D-Gal-(1→4)-β-D-GalNAc-(1→3)-β-D-Gal-(1→4)-D-Glc)不是底物。