Day A J, Cañada F J, Díaz J C, Kroon P A, Mclauchlan R, Faulds C B, Plumb G W, Morgan M R, Williamson G
Diet, Health and Consumer Science Division, Institute of Food Research, Norwich Research Park, Colney, Norwich, UK.
FEBS Lett. 2000 Feb 25;468(2-3):166-70. doi: 10.1016/s0014-5793(00)01211-4.
Lactase phlorizin hydrolase (LPH; EC 3.2.1.62) is a membrane-bound, family 1 beta-glycosidase found on the brush border of the mammalian small intestine. LPH, purified from sheep small intestine, was capable of hydrolysing a range of flavonol and isoflavone glycosides. The catalytic efficiency (k(cat)/K(m)) for the hydrolysis of quercetin-4'-glucoside, quercetin-3-glucoside, genistein-7-glucoside and daidzein-7-glucoside was 170, 137, 77 and 14 (mM(-1) s(-1)) respectively. The majority of the activity occurred at the lactase and not phlorizin hydrolase site. The ability of LPH to deglycosylate dietary (iso)flavonoid glycosides suggests a possible role for this enzyme in the metabolism of these biologically active compounds.
乳糖酶根皮苷水解酶（LPH；EC 3.2.1.62）是一种存在于哺乳动物小肠刷状缘的膜结合1型β-糖苷酶。从绵羊小肠中纯化得到的LPH能够水解一系列黄酮醇和异黄酮糖苷。槲皮素-4'-葡萄糖苷、槲皮素-3-葡萄糖苷、染料木黄酮-7-葡萄糖苷和大豆苷元-7-葡萄糖苷水解的催化效率（k(cat)/K(m)）分别为170、137、77和14（mM⁻¹ s⁻¹）。大部分活性发生在乳糖酶而非根皮苷水解酶位点。LPH使膳食（异）黄酮糖苷去糖基化的能力表明该酶在这些生物活性化合物的代谢中可能发挥作用。
