THE ROLES OF NOVEL LECTINS IN HOST DEFENSE SYSTEM FOUND IN RABBIT SERA.

我们在兔和人的血清中发现了新的凝集素和凝集素样蛋白。兔血清凝集素（rsl - 1）可识别低聚糖结构，血H型陆地2型（Fuc α 1-2 Gal β 1-3/4 GlcNAc β）和n -乙酰乳胺可凝集人红细胞。采用Synsorb H 2型亲和层析、凝胶过滤和制备型聚丙烯酰胺凝胶电泳对兔血清凝集素进行纯化。经凝胶过滤和sds -聚丙烯酰胺凝胶电泳计算，凝集素的分子量约为650000和65000。此外，我们还从兔血清中分离纯化了一种新的磷脂/神经节苷结合蛋白（pg结合蛋白）。pg结合蛋白与sepphacryl S凝胶结合，通过凝胶过滤和制备性聚丙烯酰胺凝胶电泳纯化。pg结合蛋白可使人红细胞凝集，其凝集反应可被磷脂（磷脂酰、多肽和磷脂酰甘油）和神经节苷脂（GM3）抑制。为了阐明该蛋白在体内的作用，我们检测了其对细菌的抑制或控制活性。它不具有抗菌活性，但对某些革兰氏阴性菌具有凝集活性。该蛋白似乎是作为86 kDa和59 kDa亚基的二硫键分子的多聚体组装的。在人血清中发现了类似的pg结合蛋白（抗plhu抗体），该蛋白与Sephacryl S凝胶和凝集兔红细胞具有亲和力。磷脂（磷脂酰丝氨酸和磷脂酰肌醇）对血凝反应有特异性抑制作用，而其他磷脂、神经节苷、糖类对血凝反应没有抑制作用。此外，该蛋白能引起豚鼠补体兔红细胞溶血。提示兔和人血清中凝集素和凝集素样蛋白可能对细菌病原体具有重要的免疫保护作用。少

We have found novel lectin and lectin-like proteins in rabbit and human sera. A rabbit serum lectin (RSL-I) which recognized oligosaccharide structures, blood group H type land type2 (Fuc alpha 1-2 Gal beta 1-3/4 GlcNAc beta) and N-acetyllactosamine agglutinated human red blood cells. The rabit serum lectin was purified using affinity chromatography on Synsorb H type 2 beads, gel filtration and preparative polyacrylamide gel electrophoresis. The molecular weight of the lectin was calculated to be approximate 650000 and 65000 on gel filtration and SDS-polyacrylamide gel eletrophoresis.Moreover we have isolated and purified a novel phospholipid/ganglioside-binding protein (PG-binding protein) from rabbit sera. The PG-binding protein bound to Sephacryl S gel and was easily purified by gel filtration and preparative polyacrylamide gel electrophoresis. The PG-binding protein agglutinated human red blood cells, and its hemagglutination reaction was inhibited by phospholipids (phosphatidylser … More ine and phosphatidylglycerol) and ganglioside (GM3). In order to clarify the role of this protein in body, we examined the inhibitory or control activity for bacteria. It did not have any antibacterial activity, but has agglutination activity for some Gram's negative bacterias.The protein seemed to be assembled as multimers of disulfide-bonded molecular of 86 kDa and 59 kDa subunits.The resemble PG-binding protein (antiPLHu-antibody) was found in human sera, and the protein had affinity for the same Sephacryl S gel and agglutinated rabbit red blood cells. The hemagglutination reaction was specifically inhibited by phospholipids (phosphatidylserine and phosphatidylinositol) but not any other phospholipids, gangliosides, saccharides. Furthermore, the protein was able to cause hemolysis of rabbit red blood cells with guinea pig complement.Thus these results suggest that lectin and lectin-like protein in rabbit and human sera might have important roles of the immunological protection against bacterial pathogens. Less