Takahashi Toshio, Kobayakawa Yoshitaka, Muneoka Yojiro, Fujisawa Yuko, Mohri Shirou, Hatta Masayuki, Shimizu Hiroshi, Fujisawa Toshitaka, Sugiyama Tsutomu, Takahara Michiyo, Yanagi Kensuke, Koizumi Osamu
Physiological Laboratory, Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan.
Comp Biochem Physiol B Biochem Mol Biol. 2003 Jun;135(2):309-24. doi: 10.1016/s1096-4959(03)00088-5.
KPNAYKGKLPIGLWamide, a novel member of the GLWamide peptide family, was isolated from Hydra magnipapillata. The purification was monitored with a bioassay: contraction of the retractor muscle of a sea anemone, Anthopleura fuscoviridis. The new peptide, termed Hym-370, is longer than the other GLWamides previously isolated from H. magnipapillata and another sea anemone, A. elegantissima. The amino acid sequence of Hym-370 is six residues longer at its N-terminal than a putative sequence previously deduced from the cDNA encoding the precursor protein. The new longer isoform, like the shorter GLWamides, evoked concentration-dependent muscle contractions in both H. magnipapillata and A. fuscoviridis. In contrast, Hym-248, one of the shorter GLWamide peptides, specifically induced contraction of the endodermal muscles in H. magnipapillata. This is the first case in which a member of the hydra GLWamide family (Hym-GLWamides) has exhibited an activity not shared by the others. Polyclonal antibodies were raised to the common C-terminal tripeptide GLWamide and were used in immunohistochemistry to localize the GLWamides in the tissue of two species of hydra, H. magnipapillata and H. oligactis, and one species of sea anemone, A. fuscoviridis. In each case, nerve cells were specifically labeled. These results suggest that the GLWamides are ubiquitous among cnidarians and are involved in regulating the excitability of specific muscles.
KPNAYKGKLPIGLWamide是GLWamide肽家族的一个新成员，从大型乳头水螅中分离得到。纯化过程通过生物测定进行监测：海葵（Anthopleura fuscoviridis）牵缩肌的收缩。这种新肽被命名为Hym - 370，比之前从大型乳头水螅和另一种海葵（A. elegantissima）中分离得到的其他GLWamides更长。Hym - 370的氨基酸序列在其N端比先前从编码前体蛋白的cDNA推导的假定序列长六个残基。与较短的GLWamides一样，这种新的更长的异构体在大型乳头水螅和A. fuscoviridis中均引起浓度依赖性的肌肉收缩。相比之下，较短的GLWamide肽之一Hym - 248特异性诱导大型乳头水螅内胚层肌肉的收缩。这是水螅GLWamide家族（Hym - GLWamides）成员首次表现出其他成员不具有的活性。针对共同的C端三肽GLWamide制备了多克隆抗体，并用于免疫组织化学，以在两种水螅（大型乳头水螅和少芽水螅）以及一种海葵（A. fuscoviridis）的组织中定位GLWamides。在每种情况下，神经细胞都被特异性标记。这些结果表明，GLWamides在刺胞动物中普遍存在，并参与调节特定肌肉的兴奋性。
