Novel peptidylglycans with hemagglufinating activity-chemical structure and biological activity

我们发现有11种海藻具有新的血凝素，这种血凝素不能用磷酸盐缓冲盐水提取，除非用Pronase预处理。新的血凝素是从红藻、石花菜和扇形红藻的Pronase处理提取物中分别分离得到的。Pronase处理依赖的血凝素通常是表观分子量分别为8×10~(-5)的肽基多聚糖。单糖主要为半乳糖和木糖，还含有糖醛酸、3，6-脱水半乳糖和硫酸酯。这些多肽部分具有相似的氨基酸组成，富含丝氨酸、甘氨酸和谷氨酸，表明它们的分子中分别存在Xyl-Ser键。‘Pronase处理依赖’血凝素显著凝集绵羊红细胞，特别是经胰酶或Pronase处理的绵羊红细胞，并对小鼠脾淋巴细胞具有促有丝分裂活性。它们在较高的温度和较宽的pH范围内都是稳定的，在低pH时有较大的增加。积雪草素和氯化钠对该酶有微弱的抑制作用，而其它糖类化合物对该酶活性无抑制作用。该酶的活性不受高碘酸氧化的影响，也不受4M盐酸胍的解离状态的影响，也不受蛋白酶、糖苷酶和硫酸酯酶等酶的消化，表明它们具有耐化学或酶攻击的化学结构。

We found that eleven species of marine algae possessed novel hemagglutinins, which could not be extracted with phosphate buffered saline, unless the algae had been pretreated with Pronase. The novel hemagglutinins have been isolated from the Pronase-treated extracts of the red algae, Gelidium amansii and Carpopeltis flabellata, respectively. The 'Pronase treatment-dependent' hemagglutinins were commonly peptidylglycans with the apparent molecular weight of 8 x 10^5, respectively. As to glycan moieties, the major monosaccharides were Gal and Xyl, and uronic acids, 3,6-anhydro-galactose and sulfate esters also detected as the constituents. The peptide moieties share similar amino acid composition rich in Ser, Gly and Glx, suggesting that Xyl-Ser linkages in their molecules, respectively.The 'Pronase treatment-dependent' hemagglutinins markedly agglutinated sheep erythrocytes, especially trypsin- or Pronase treated ones, and also showed mitogenic activity for splenic lymphocytes of mice. They were stable at a high temperature and in a wide range of pH with rather increase at a low pH. The activity was weakly inhibited by asialofetuin and NaCl,but not by other sugar compounds tested. The activity was not affected by periodic acid oxidation or under the dissociation state with 4M guanidine-HCl as well as digestion with enzymes such as protease, glycosidases and sulfatase, which suggest that they have chemical structures resistant to chemical or enzymatic attacks examined.