Eda S, Suzuki Y, Kawai T, Ohtani K, Kase T, Sakamoto T, Wakamiya N
Department of Pathology, Osaka Prefectural Institute of Public Health, Japan.
Biosci Biotechnol Biochem. 1998 Jul;62(7):1326-31. doi: 10.1271/bbb.62.1326.
Mannan-binding protein (MBP) is a calcium-dependent mammalian serum lectin important in first-line host defense. MBP belongs to the collectin family, which is characterized by an NH2-terminal cysteine-rich domain, a collagen-like domain, a neck domain, and a carbohydrate recognition domain (CRD). We have expressed a recombinant human MBP, consisting of the short collagen region (two repeats of Gly-Xaa-Yaa amino acid sequences), the neck domain, and the CRD, in Escherichia coli. The truncated MBP was capable of forming trimers by association of the neck domain and could bind sugar with a specificity similar to that of the native form. Results of hemagglutination inhibition (HI) assay of influenza A virus showed that the truncated MBP inhibited hemagglutination less strongly, although the native MBP induced the HI phenomenon. These results suggest that an oligomeric structure is an advantage for MBP to have full biological activity against influenza A virus.
甘露聚糖结合蛋白（MBP）是一种钙依赖性哺乳动物血清凝集素，在宿主一线防御中起重要作用。MBP属于胶原凝集素家族，其特征在于氨基末端富含半胱氨酸结构域、胶原样结构域、颈部结构域和碳水化合物识别结构域（CRD）。我们在大肠杆菌中表达了一种重组人MBP，它由短胶原区域（Gly-Xaa-Yaa氨基酸序列的两个重复）、颈部结构域和CRD组成。截短的MBP能够通过颈部结构域的缔合形成三聚体，并且能够以与天然形式相似的特异性结合糖类。甲型流感病毒血凝抑制（HI）试验结果表明，尽管天然MBP可诱导HI现象，但截短的MBP抑制血凝的能力较弱。这些结果表明，寡聚结构是MBP对甲型流感病毒具有完全生物活性的一个优势。
