Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Japan.
Toxicon. 2010 Jun 1;55(6):1119-24. doi: 10.1016/j.toxicon.2009.12.021. Epub 2010 Jan 4.
Puffer fish saxitoxin and tetrodotoxin binding protein (PSTBP) is a glycoprotein (200 kDa as a dimer) that we previously isolated from the plasma of Fugu pardalis (Yotsu-Yamashita et al., 2001). For the study on functions of PSTBP, here we examined distribution of homologous proteins to PSTBP in the plasma of seven species of puffer fish, and among the tissues of F. pardalis by Western blot analysis probed with a polyclonal IgG against unglycosylated PSTBP1 expressed in Echelichia coli. One or two major positive broad bands were detected at 105-140 kDa molecular weight range in the plasma (0.5 microg protein) of all species of puffer fish tested, while no band was detected in the plasma (5 microg protein) of fish other than puffer fish. Glycopeptidase F treated plasma of all species of puffer fish tested commonly showed the bands at approximately 42 kDa that was consistent to the molecular weight of unglycosylated PSTBP. These data suggest that puffer fish commonly possess glycoproteins homologous to PSTBP, but the sizes of N-glycan are specific to the species. Among soluble protein extracts (5 microg protein) from the tissues of F. pardalis, PSTBP was detected in all tissues examined, most prominently in heart, skin, and gall.
河豚鱼石房蛤毒素和河豚毒素结合蛋白（PSTBP）是一种糖蛋白（二聚体为 200 kDa），我们之前从豹纹东方豚（Fugu pardalis）的血浆中分离得到（Yotsu-Yamashita 等人，2001）。为了研究 PSTBP 的功能，我们通过 Western blot 分析，用针对在大肠杆菌中表达的未糖基化 PSTBP1 的多克隆 IgG 探测，检查了七种河豚鱼的血浆中和 F. pardalis 组织中同源蛋白的分布。在所有测试的河豚鱼的血浆（0.5 μg 蛋白）中，在 105-140 kDa 分子量范围内检测到一个或两个主要的阳性宽带，而在除河豚鱼以外的鱼类的血浆（5 μg 蛋白）中未检测到带。用糖苷酶 F 处理所有测试的河豚鱼的血浆后，通常会在大约 42 kDa 处出现与未糖基化 PSTBP 分子量一致的带。这些数据表明，河豚鱼通常具有与 PSTBP 同源的糖蛋白，但 N-聚糖的大小是特定于物种的。在 F. pardalis 组织的可溶性蛋白提取物（5 μg 蛋白）中，在所有检查的组织中都检测到 PSTBP，在心脏、皮肤和胆囊中最为明显。
