Marks N J, Shaw C, Halton D W, Thim L
Comparative Neuroendocrinology Research Group, School of Clinical Medicine, Queen's University of Belfast, UK.
Regul Pept. 1993 Sep 3;47(2):179-85. doi: 10.1016/0167-0115(93)90422-5.
Pancreatic polypeptide (PP) has been isolated from extracts of the pancreas of the European hedgehog (Erinaceous europaeus) which is a representative of the order Insectivora, deemed to be the most primitive group of placental mammals. Pancreatic tissues were extracted in acidified ethanol and the peptide was purified chromatographically using a PP C-terminal hexapeptide amide specific radioimmunoassay to monitor purification. Two major PP-immunoreactive peptides were baseline-resolved following the final analytical reverse phase HPLC fractionation. Each was separately subjected to plasma desorption mass spectroscopy (PDMS) and gas-phase sequencing. The molecular masses of each peptide were similar: (I) 4237.6 +/- 4 Da and (II) 4238.2 +/- 4 Da. The full primary structures of each peptide were deduced and these were identical: VPLEPVYPGDNATPEQMAHYAAELRRYINMLTRPRY. The peptides were deemed to be amidated due to their full molar cross-reactivity with the amide-requiring PP antiserum employed in radioimmunoassay. The molecular mass (4233.8 Da) calculated from the sequence was in close agreement with PDMS estimates and the reason for the different retention times of each peptide is unknown at present. Hedgehog PP exhibits only 2 unique amino acid substitutions, at positions 1 (Val) and 19 (His), when compared with other mammalian analogues.
胰多肽（PP）已从欧洲刺猬（Erinaceous europaeus）的胰腺提取物中分离出来，欧洲刺猬是食虫目动物的代表，被认为是胎盘哺乳动物中最原始的群体。胰腺组织用酸化乙醇提取，该肽通过使用PP C末端六肽酰胺特异性放射免疫测定法进行色谱纯化以监测纯化过程。在最终的分析反相高效液相色谱分级分离后，两种主要的PP免疫反应性肽在基线处得到分离。每种肽分别进行等离子体解吸质谱（PDMS）和气相测序。每种肽的分子量相似：（I）4237.6±4 Da和（II）4238.2±4 Da。推导了每种肽的完整一级结构，且这些结构相同：VPLEPVYPGDNATPEQMAHYAAELRRYINMLTRPRY。由于它们与放射免疫测定中使用的需要酰胺的PP抗血清具有完全的摩尔交叉反应性，因此这些肽被认为是酰胺化的。根据序列计算出的分子量（4233.8 Da）与PDMS估计值非常一致，目前每种肽保留时间不同的原因尚不清楚。与其他哺乳动物类似物相比，刺猬PP仅在第1位（Val）和第19位（His）表现出2个独特的氨基酸取代。
