Lloyd P E, Connolly C M
Department of Pharmacological and Physiological Sciences, University of Chicago, Illinois 60637.
J Neurosci. 1989 Jan;9(1):312-7. doi: 10.1523/JNEUROSCI.09-01-00312.1989.
We report the identification of a novel neuropeptide from Aplysia nervous tissue. The peptide was termed Pedal peptide (Pep) because it was predominantly synthesized in the pedal ganglia. Pep was purified and sequenced from pooled extracts of pedal ganglia. The following sequence was proposed: Pro-Leu-Asp-Ser-Val-Tyr-Gly-Thr-His-Gly-Met-Ser-Gly-Phe-Ala. Enzymatic hydrolysis procedures indicated that Pep had a free carboxyl terminal. A peptide with the proposed sequence was synthesized and compared with the native peptide. Chromatographic properties of the 2 peptides under 3 different conditioned were compared and found to be identical. Electrophysiological responses to the 2 peptides were compared on an identified neuron in the abdominal ganglia and found to be qualitatively and quantitatively very similar. Both peptides produced net inward currents that were associated with a decrease in membrane conductance. The results from these 2 procedures confirmed that the proposed Pep sequence was correct. Quantitative measurements of the incorporation of 35S-methionine into Pep suggest that cell bodies that synthesize Pep were present predominantly in the pedal ganglia but should also be found in other central ganglia as well. Pep-like immunoreactive neurons are found predominantly in the pedal ganglia and less frequently in the other ganglia (Pearson and Lloyd, 1989). Quantitatively, Pep constitutes one of the predominant peptides in the nervous system of Aplysia. Pep does not appear to be a member of any other previously identified invertebrate or vertebrate peptide family.
我们报告了从海兔神经组织中鉴定出一种新型神经肽。该肽被命名为足肽（Pep），因为它主要在足神经节中合成。Pep是从足神经节的混合提取物中纯化并测序的。提出了以下序列：Pro-Leu-Asp-Ser-Val-Tyr-Gly-Thr-His-Gly-Met-Ser-Gly-Phe-Ala。酶解程序表明Pep具有游离羧基末端。合成了具有所提出序列的肽，并与天然肽进行了比较。比较了这两种肽在3种不同条件下的色谱性质，发现它们是相同的。在腹神经节中的一个已鉴定神经元上比较了对这两种肽的电生理反应，发现它们在定性和定量上非常相似。两种肽都产生了与膜电导降低相关的内向净电流。这两个程序的结果证实了所提出的Pep序列是正确的。对35S-甲硫氨酸掺入Pep的定量测量表明，合成Pep的细胞体主要存在于足神经节中，但在其他中枢神经节中也应该可以找到。Pep样免疫反应性神经元主要存在于足神经节中，在其他神经节中较少见（Pearson和Lloyd，1989）。从数量上看，Pep是海兔神经系统中主要的肽之一。Pep似乎不属于任何其他先前鉴定的无脊椎动物或脊椎动物肽家族。
