An O-acetyl sialic acid specific lectin was purified from the hemolymph of the marine crab Atergatis integerrimus by affinity chromatography using BSM (Bovine Submaxillary Mucin) coupled to cyanogen bromide activated Sepharose 4B and biospecific adsorption using formalinized buffalo erythrocytes. The purified AiL (Atergatis integerrimus lectin) showed an 1218 fold increase in specific activity when compared to the crude hemolymph agglutinin. The lectin, on non - denaturing PAGE showed a single band of 216 kDa and when subjected to SDS - PAGE, the lectin resolved into three subunits of molecular weight 70, 72 and 74 kDa. Physico chemical characterization revealed the lectin as pH and temperature sensitive, calcium dependent and sensitive to calcium chelators. Based on the calcium dependency of the lectin, AiL could be classified as a C-type lectin. The purified lectin agglutinated buffalo erythrocytes with greater avidity and was inhibited by the glycoproteins BSM, thyroglobulin, fetuin, PSM, and sugars raffinose, trehalose, l - fucose, α - Lactose, melibiose and GluNAc suggesting the affinity of the lectin to sialic acid. Reduction in HA with asialo buffalo erythrocytes and HAI titer with desialylated BSM, confirms the sialic acid specificity of the lectin. The reduction in HAI following de - O - acetylation confirms the specificity of the lectin for O - acetyl sialic acid. FTIR analysis confirms the purified lectin as a glycoprotein with spectral bands corresponding to amide bands and saccharides. Thus this study paves way to assess the therapeutic application of this lectin that could be targeted to modified sialic acid moieties that are expressed on the malignant cells and pathogenic microbes and also deduce the crystal structure of the lectin.

O-乙酰唾液酸特异性凝集素是从蛑的血淋巴纯化Atergatis integerrimus由耦合到溴化氰亲和力使用色谱法BSM（牛颌下腺粘蛋白）活化的Sepharose 4B和生物特异性吸附用甲醛处理水牛红细胞。纯化的AiL（Atergatis integerrimus与粗品血淋巴凝集素相比，凝集素）的比活性提高了1218倍。凝集素在非变性PAGE上显示一条216 kDa的单条带，当进行SDS-PAGE时，该凝集素分解为三个分子量分别为70、72和74 kDa的亚基。物理化学表征表明该凝集素对pH和温度敏感，对钙具有依赖性并且对钙螯合剂敏感。根据凝集素对钙的依赖性，AiL可归为C型凝集素。纯化的凝集素凝集的水牛红细胞具有更高的亲和力，并被糖蛋白BSM，甲状腺球蛋白，胎球蛋白，PSM和糖类棉子糖，海藻糖，l抑制-岩藻糖，α-乳糖，半乳糖和GluNAc，表明凝集素对唾液酸的亲和力。用去唾液酸水牛红细胞降低HA，用去唾液酸化的BSM降低HAI滴度，证实了凝集素的唾液酸特异性。脱-O-乙酰化后HAI的减少证实了凝集素对O-乙酰唾液酸的特异性。FTIR分析证实纯化的凝集素为糖蛋白，其光谱带对应于酰胺带和糖类。因此，该研究为评估该凝集素的治疗应用铺平了道路，该凝集素可以靶向在恶性细胞和病原微生物上表达的修饰的唾液酸部分，并且还可以推导该凝集素的晶体结构。