Shin Kouichirou, Wakabayashi Hiroyuki, Yamauchi Koji, Yaeshima Tomoko, Iwatsuki Keiji
Food Science & Technology Institute, Morinaga Milk Industry Co., Ltd, Kanagawa, Japan.
Biol Pharm Bull. 2008 Aug;31(8):1605-8. doi: 10.1248/bpb.31.1605.
Intelectin (IntL), a lectin that exists on the brush border membrane of the small intestine, plays a role in the innate immune response and also acts as a receptor for lactoferrin (LF), an iron-binding glycoprotein found in milk and other secretions. Similar to human LF (hLF), bovine LF (bLF) has been shown to induce proliferation and differentiation of human enterocytes and to modulate their cytokine productions. To evaluate the interaction between human IntL (hIntL) and bLF, recombinant hIntL (rhIntL) conjugated with a tag sequence was examined for its ligand-binding capacity by using microtiter plates coated with LF or other proteins. Interestingly, rhIntL showed higher binding for bLF than hLF. It also bound pepsin hydrolysate of bLF, but to a lower degree than native bLF. A very low binding of rhIntL was observed for bovine serum albumin or transferrin. These findings suggest that hIntL acts as a receptor for bLF and its digested fragments.
整合素（IntL）是一种存在于小肠刷状缘膜上的凝集素，在先天免疫反应中发挥作用，同时也是乳铁蛋白（LF）的受体，乳铁蛋白是一种在牛奶和其他分泌物中发现的铁结合糖蛋白。与人类乳铁蛋白（hLF）类似，牛乳铁蛋白（bLF）已被证明可诱导人肠上皮细胞的增殖和分化，并调节其细胞因子的产生。为了评估人类整合素（hIntL）与bLF之间的相互作用，通过使用包被有LF或其他蛋白质的微量滴定板，检测了与标签序列缀合的重组hIntL（rhIntL）的配体结合能力。有趣的是，rhIntL对bLF的结合力高于hLF。它也能结合bLF的胃蛋白酶水解产物，但结合程度低于天然bLF。rhIntL与牛血清白蛋白或转铁蛋白的结合力非常低。这些发现表明，hIntL是bLF及其消化片段的受体。
