Ameye L, De Becker G, Killian C, Wilt F, Kemps R, Kuypers S, Dubois P
Laboratoire de Biologie marine, Université Libre de Bruxelles, 50 Avenue F.D. Roosevelt, Brussels, 1050, Belgium.
J Struct Biol. 2001 Apr;134(1):56-66. doi: 10.1006/jsbi.2001.4361.
Properties of the echinoderm skeleton are under biological control, which is exerted in part by the organic matrix embedded in the mineralized part of the skeleton. This organic matrix consists of proteins and glycoproteins whose carbohydrate component is specifically involved in the control mechanisms. The saccharide moiety of the organic matrix of the spines of the echinoid Paracentrotus lividus was characterized using enzyme-linked lectin assays (ELLAs). O-glycoproteins, different types of complex N-glycoproteins, and terminal sialic acids were detected. Sialic acids are known to interact with Ca ions and could play an important role in the mineralization process. Some of the carbohydrate components detected by ELLAs as well as two organic matrix proteins (SM30 and SM50) were localized within different subregions of the spine skeleton using field-emission scanning electron microscopy. The mappings show that some of these components are not homogeneously distributed in the different skeletal subregions. For example, some N-glycoproteins were preferentially located in the putative amorphous subregion of the skeleton, whereas some O-glycoproteins were localized in the subregion where skeletal growth is inhibited. These results suggest that the biological control exerted on the skeletal properties can be partly modulated by local differences in the organic matrix composition.
棘皮动物骨骼的特性受生物控制，部分控制作用是由嵌入骨骼矿化部分的有机基质发挥的。这种有机基质由蛋白质和糖蛋白组成，其碳水化合物成分特别参与控制机制。使用酶联凝集素测定法（ELLAs）对海胆Paracentrotus lividus棘刺有机基质的糖部分进行了表征。检测到了O-糖蛋白、不同类型的复合N-糖蛋白和末端唾液酸。已知唾液酸与钙离子相互作用，可能在矿化过程中起重要作用。利用场发射扫描电子显微镜，ELLAs检测到的一些碳水化合物成分以及两种有机基质蛋白（SM30和SM50）被定位在棘刺骨骼的不同亚区域内。图谱显示，其中一些成分在不同的骨骼亚区域中分布不均匀。例如，一些N-糖蛋白优先位于骨骼假定的无定形亚区域，而一些O-糖蛋白则位于骨骼生长受抑制的亚区域。这些结果表明，对骨骼特性的生物控制可以部分地由有机基质组成的局部差异来调节。
