棕尾别麻蝇(Sarcophaga peregrina)幼虫与蛹血淋巴凝集素的纯化与特性

用亲和层析法纯化了棕尾别麻蝇幼虫和蛹血淋巴凝集素。以兔红细胞吸附幼虫血淋巴凝集素为抗原制备的抗体、球球蛋白和甲状腺蛋白等三种亲和层析吸附剂纯化得到的幼虫凝集素是相同的，其分子量73kD左右。用甲状腺球蛋白为亲和配基纯化的蛹血淋巴凝集素由二种亚基组成，其分子量分别为30和32kD。幼虫和蛹血淋巴凝集素活性的抑制糖明显不同：乳糖、岩藻糖和N－乙酰半乳糖胺对幼虫血淋巴凝集素活性有抑制作用；而甘露糖胺、半乳糖胺和葡萄糖胺则对蛹血淋巴集素有一定抑制。而且，用兔红细胞吸附幼虫血淋巴凝集素为抗原制备的抗血清对蛹的凝集素活性无交叉反应，表明这两种凝集素是不相同的。虽然本文所纯化的麻蝇蛹血淋巴凝集素的分子量和Komano等报道的麻蝇蛹以及幼虫体壁 伤害诱导的凝集素SPL相同，但其糖的抑制特性有明显差异。

PURIFICATION AND CHARACTERISTICS OF HAEMOLYMPH LECTINS IN SARCOPHAGA PEREGRINA LARVAE AND PUPA

Lectins in haemolymph of Sarcophaga peregrina larvae and pupa were purified by affinity chromatography. Antiserum against larvae haemolymph lectin and two glycoproteins, fetuin and thyroglobulin, were used as affinity ligands for purification of larvae lectin. SDS-PAGE results indicated that, the lectin purified from larvae haemolymph was a monomer with molecular weight (Mr) around 73kD; while the lectin from pupa was composed of two subunits, with Mr 30 and 33 kD, respectively. The carbohydrates, which inhibited haemagglutination activity (HA) in haemolymph of larvae and pupa, were different. It showed that HA was inhibited by lactose, fucose and N-acetylgalactosamine in the larvae, and inhibited by mannosamine, glactosamine and glucosamine in the pupa. The antiserum against larvae lectin had no cross reaction to the pupa lectin. It was suggested that the lectin purified from larvae is different from that in pupa. Compared with the other studies on S.peregrina lectins, the inhibiting sugars to the pupa lectin activity as revealed in this study were quite different from those existed in pupa and wounded larvae reported by Komano et al., although the subunites Mr of the former were the same as that of the latter.