Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan.
Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
Int J Mol Sci. 2021 Jan 22;22(3):1081. doi: 10.3390/ijms22031081.
Previously, we isolated jacalin-related lectins termed PPL2, PPL3 (PPL3A, 3B and 3C) and PPL4 from the mantle secretory fluid of (Mabe) pearl shell. They showed the sequence homology with the plant lectin family, jacalin-related β-prism fold lectins (JRLs). While PPL3s and PPL4 shared only 35%-50% homology to PPL2A, respectively, they exhibited unique carbohydrate binding properties based on the multiple glycan-binding profiling data sets from frontal affinity chromatography analysis. In this paper, we investigated biomineralization properties of these lectins and compared their biomineral functions. It was found that these lectins showed different effects on CaCO crystalization, respectively, although PPL3 and PPL2A showed similar carbohydrate binding specificities. PPL3 suppressed the crystal growth of CaCO calcite, while PPL2A increased the number of contact polycrystalline calcite composed of more than one crystal with various orientations. Furthermore, PPL4 alone showed no effect on CaCO crystalization; however, PPL4 regulated the size of crystals collaborated with -acetyl-D-glucosamine and chitin oligomer, which are specific in recognizing carbohydrates for PPL4. These observations highlight the unique functions and molecular evolution of this lectin family involved in the mollusk shell formation.
先前，我们从 （Mabe）珍珠贝的套膜分泌液中分离出了几丁质结合凝集素相关的凝集素，称为 PPL2、PPL3（PPL3A、3B 和 3C）和 PPL4。它们与植物凝集素家族、几丁质结合β-折叠凝集素（JRLs）具有序列同源性。虽然 PPL3s 和 PPL4 与 PPL2A 的同源性分别仅为 35%-50%，但它们基于 Frontal Affinity Chromatography 分析的多个糖结合谱数据集显示出独特的碳水化合物结合特性。在本文中，我们研究了这些凝集素的生物矿化特性，并比较了它们的生物矿化功能。结果发现，尽管 PPL3 和 PPL2A 表现出相似的碳水化合物结合特异性，但这些凝集素对 CaCO3 结晶的影响不同。PPL3 抑制了 CaCO3 方解石的晶体生长，而 PPL2A 增加了由多个具有不同取向的晶体组成的多晶方解石的接触数量。此外，PPL4 本身对 CaCO3 结晶没有影响；然而，PPL4 与 -乙酰-D-葡萄糖胺和几丁质寡糖协同调节晶体大小，这些物质是 PPL4 识别碳水化合物的特异性物质。这些观察结果突出了参与软体动物壳形成的这种凝集素家族的独特功能和分子进化。
