Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
Center for Interdisciplinary Research, Tohoku University, Sendai 980-8578, Japan.
Int J Mol Sci. 2019 Sep 18;20(18):4629. doi: 10.3390/ijms20184629.
We determined the primary structures of jacalin-related lectins termed PPL3s (PPL3A, 3B, and 3C, which are dimers consisting of sequence variants α + α, α + β, β + β, respectively) and PPL4, which is heterodimer consisting of α + β subunits, isolated from mantle secretory fluid of (Mabe) pearl shell. Their carbohydrate-binding properties were analyzed, in addition to that of PPL2A, which was previously reported as a matrix protein. PPL3s and PPL4 shared only 35-50% homology to PPL2A, respectively; they exhibited significantly different carbohydrate-binding specificities based on the multiple glycan binding profiling data sets from frontal affinity chromatography analysis. The carbohydrate-binding specificity of PPL3s was similar to that of PPL2A, except only for ManFucXylGlcNAc oligosaccharide, while PPL4 showed different carbohydrate-binding specificity compared with PPL2A and PPL3s. PPL2A and PPL3s mainly recognize agalactosylated- and galactosylated-type glycans. On the other hand, PPL4 binds to high-mannose-and hybrid-type N-linked glycans but not agalactosylated- and galactosylated-type glycans.
我们确定了从（Mabe）珍珠贝的套膜分泌液中分离得到的 jacalin 相关凝集素 PPL3s（PPL3A、3B 和 3C，它们分别由序列变体 α+α、α+β 和 β+β 组成的二聚体）和 PPL4 的一级结构，后者是由 α+β 亚基组成的异二聚体。除了之前报道的基质蛋白 PPL2A 外，我们还分析了它们的碳水化合物结合特性。PPL3s 和 PPL4 与 PPL2A 的同源性分别仅为 35-50%；根据来自前沿亲和层析分析的多个聚糖结合分析数据集，它们表现出明显不同的碳水化合物结合特异性。PPL3s 的碳水化合物结合特异性与 PPL2A 相似，除了 ManFucXylGlcNAc 寡糖外，而 PPL4 与 PPL2A 和 PPL3s 相比表现出不同的碳水化合物结合特异性。PPL2A 和 PPL3s 主要识别半乳糖基化和乳糖基化型聚糖。另一方面，PPL4 结合高甘露糖型和杂合型 N-连接聚糖，但不结合半乳糖基化和乳糖基化型聚糖。
