Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan.
Department of Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA.
Carbohydr Polym. 2015 Dec 10;134:557-65. doi: 10.1016/j.carbpol.2015.07.082. Epub 2015 Aug 11.
There are several reports that chondroitin sulfate containing K-type units [GlcA (3S)-GalNAc (4S)] exhibiting similar levels of neurite outgrowth promoting activities as CS having high amounts of B-, D- and E-type disulfated disaccharides. Although CS containing K-type units possess important biological activities, there are only few sources, such as king crab cartilage, squid cartilage or sea cucumber. In this study, CS containing 13.9% of K-type units was found in octopus (Enteroctopus dofleini) cartilage using different substrate specificities of chondroitinases. The 2D NMR spectra showed cross-peaks assigned to protons on sugar ring of GlcA (3S), demonstrating the presence of K-type units in octopus CS. Furthermore, proportion of fucosylated disaccharide units in octopus CS was very low. Octopus CS showed high affinity for growth factors and stimulated neurite outgrowth of hippocampal neurons, similar to the activity of squid CS-E. These results strongly suggest that octopus cartilage is a rich source of CS-K and has important biological activities.
有几份报告表明，含有 K 型单元（GlcA(3S)-GalNAc(4S)）的硫酸软骨素与含有大量 B、D 和 E 型二硫酸化二糖的 CS 具有相似水平的促进神经突生长的活性。尽管含有 K 型单元的 CS 具有重要的生物学活性，但只有少数来源，如帝王蟹软骨、鱿鱼软骨或海参。在这项研究中，使用不同的软骨素酶的底物特异性，在章鱼（Enteroctopus dofleini）软骨中发现了含有 13.9%的 K 型单元的 CS。二维 NMR 谱显示了 GlcA(3S)糖环上质子的交叉峰，表明章鱼 CS 中存在 K 型单元。此外，章鱼 CS 中的岩藻糖基二糖单元比例非常低。章鱼 CS 对生长因子具有高亲和力，并刺激海马神经元的神经突生长，类似于鱿鱼 CS-E 的活性。这些结果强烈表明，章鱼软骨是 CS-K 的丰富来源，具有重要的生物学活性。
