Bonato C, Eng J, Pan Y C, Miedel M, Hulmes J D, Yalow R S
Life Sci. 1986 Sep 15;39(11):959-64. doi: 10.1016/0024-3205(86)90283-3.
Only two 34 amino acid gastrin precursors have previously been purified and sequenced, those of pig and of human. The larger molecular form generally accounts for only about 5% of antral gastrin in most species. This report describes the purification of "big gastrin" from guinea pig (GP) antra. Two hundred grams of antra were defatted with acetone and the acetone cakes were extracted with 0.1M NH4HCO3. The extract was concentrated by adsorption onto and batch elution from QA-52 anion exchange cellulose. Fractionation on a mu Bondapak C18 cartridge resolved 3.6 nmol of the larger peptide from 61 nmol of immunoreactive gastrin in the original extract. Two additional HPLC steps brought the peptide to final purity. GP big gastrin is a 33 amino acid peptide with the following sequence: less than ELGPQVPAHLRTDLSKKQGPWAEEEAAYGWMDF# The GP peptide is different from pig G34 in 6 of the 17 NH2-terminal amino acids as well as in the previously reported deletion of a glutamic acid in the COOH-terminus.
此前仅纯化并测序了两种由34个氨基酸组成的胃泌素前体，即猪和人的胃泌素前体。在大多数物种中，较大分子形式的胃泌素通常仅占胃窦胃泌素的约5%。本报告描述了从豚鼠胃窦中纯化“大胃泌素”的过程。用丙酮对200克胃窦进行脱脂处理，然后用0.1M碳酸氢铵对丙酮饼进行萃取。通过吸附到QA - 52阴离子交换纤维素上并进行分批洗脱来浓缩提取物。在μ Bondapak C18柱上进行分级分离，从原始提取物中的61 nmol免疫反应性胃泌素中分离出3.6 nmol较大的肽段。另外两个高效液相色谱步骤使该肽段达到最终纯度。豚鼠大胃泌素是一种由33个氨基酸组成的肽段，其序列如下：小于ELGPQVPAHLRTDLSKKQGPWAEEEAAYGWMDF# 该豚鼠肽段在17个氨基末端氨基酸中的6个以及在先前报道的羧基末端谷氨酸缺失方面与猪G34不同。
