Birenheide R, Tamori M, Motokawa T, Ohtani M, Iwakoshi E, Muneoka Y, Fujita T, Minakata H, Nomoto K
Basic Biology, Faculty of Bioscience and Biotechnology, Tokyo Institue of Technology, Japan.
Biol Bull. 1998 Jun;194(3):253-9. doi: 10.2307/1543095.
We present the first evidence of a system of four bioactive peptides that affect the stiffness of sea cucumber dermis. The body wall dermis of sea cucumbers consists of catch connective tissue that is characterized by quick and drastic stiffness changes under nervous control. The peptides were isolated from the body wall, their amino acid sequences determined, and identical peptides synthesized. Two peptides, which we named holokinins, are homologous with bradykinin. We tested the effect of the peptides on the mechanical properties of sea cucumber dermis. Both of the holokinins softened the dermis, and a pentapeptide that we designated as NGIWYamide stiffened it. Both effects were reversibly suppressed by anesthesia with menthol. We called the fourth peptide stichopin; it had no direct effect on the stiffness of the dermis but suppressed action of the neurotransmitter acetylcholine reversibly. The results suggest that the peptides are neuropeptides and are part of a sophisticated system of neurotransmitters and neuromodulators that controls the connective tissue stiffness of sea cucumber dermis.
我们首次证明了一个由四种生物活性肽组成的系统，该系统会影响海参真皮的硬度。海参的体壁真皮由可收缩结缔组织构成，其特点是在神经控制下硬度会迅速且剧烈地变化。从体壁中分离出这些肽，测定了它们的氨基酸序列，并合成了相同的肽。其中两种肽，我们命名为全激肽，与缓激肽同源。我们测试了这些肽对海参真皮力学性能的影响。两种全激肽都使真皮变软，而我们命名为NGIWYamide的五肽则使其变硬。这两种作用都被薄荷醇麻醉可逆地抑制。我们将第四种肽称为刺参肽；它对真皮硬度没有直接影响，但能可逆地抑制神经递质乙酰胆碱的作用。结果表明，这些肽是神经肽，是控制海参真皮结缔组织硬度的复杂神经递质和神经调节剂系统的一部分。
