Binding of the VCHSKT peptide to ceramide‐rich and cholesterol‐rich domains of cell membranes in rat pancreatic glands
Binding of the VCHSKT peptide to ceramide‐rich and cholesterol‐rich domains of cell membranes in rat pancreatic glands
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VCHSKT 肽与大鼠胰腺细胞膜富含神经酰胺和胆固醇的结构域的结合
DOI：
10.1002/sia.5020
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发表时间：
2013
影响因子：
1.7
通讯作者：
H. Nygren
中科院分区：
文献类型：
--
作者：
S. Lange;P. Malmberg;H. Nygren
具有抗分泌作用的肽已被定义，并被称为抗分泌因子（AF-16），具有16个氨基酸的序列。使用三氟乙酸（TFA）作为电离催化剂，通过飞行时间二次离子质谱法（TOF-西姆斯）容易地检测到较短的序列AF-6肽（VCHSKT，Pepceuticals Ltd，莱斯特，英格兰）。参比样品的分析显示在m/z 657处存在假分子离子，在m/z 679处存在M + Na+。在暴露于肽的动物的组织样品中也检测到这些峰。将AF-6肽静脉内注射或喷雾到Sprague-Dawley大鼠的鼻孔中，250-300 g（n = 5）。用异氟烷麻醉动物。在2 h后采集胰腺组织样本，并在LIGHT-EMPACT中高压冷冻，用0.1% TFA喷雾，并在哥德堡大学使用配备Bi 3 +-液态金属离子枪的TOF-西姆斯V仪器（ION-TOF，GmbH，Münster，德国）进行分析。在暴露动物和对照动物的胰腺中，AF-6肽的分布为高强度点，不均匀分布在磷脂酰胆碱头基m/z 184高强度的区域，表明定位于胰腺细胞的膜部分。肽与半乳糖神经酰胺c18：0和胆固醇的点状分布共定位。胆固醇和半乳糖醛酸是称为脂筏的专门膜区域的已知脂质组分。结果表明，AF-6肽与大鼠胰腺细胞的这些区域中存在的细胞受体结合。版权所有© 2012约翰威利父子有限公司.
A peptide with antisecretory effect has been defined and was denoted the antisecretory factor (AF‐16) with a sequence of 16 amino acids. A shorter sequence, the AF‐6 peptide (VCHSKT, Pepceuticals Ltd, Leicester, England), is readily detected by Time of Flight Secondary Ion Mass Spectrometry (TOF‐SIMS), using trifluoroacetic acid (TFA) as ionization catalyzer. Analysis of a reference sample revealed a pseudo‐molecular ion at m/z 657 and M + Na+ at m/z 679. These peaks were also detected in tissue samples of animals exposed to the peptide. The AF‐6 peptide was injected intravenously or sprayed into the nostrils of Sprague–Dawley rats, 250–300 g (n = 5). The animals were anesthetized with isoflurane. Pancreas tissue samples were taken after 2 h and were high‐pressure frozen in a Lecia EMPACT, sprayed with 0.1% TFA, and analyzed using a TOF‐SIMS V instrument (ION‐TOF, GmbH, Münster, Germany) equipped with a Bi3+‐liquid metal ion gun at the University of Gothenburg. The distribution of the AF‐6 peptide could be seen in the pancreas of exposed animals and control animals as high‐intensity dots that were heterogeneously distributed in regions with a high intensity of phosphatidylcholine head group m/z 184, indicating a localization to the membrane portion of the pancreatic cells. The peptide was colocalized with a dot‐like distribution of galactocylceramide c18:0 and cholesterol. Cholesterol and gal‐Cer are known lipid components of specialized membrane areas called lipid rafts. The results indicate that the AF‐6 peptide binds to cellular receptors present in such regions of rat pancreatic cells. Copyright © 2012 John Wiley & Sons, Ltd.