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从猪胰脏的酸醇提取液中纯化了一个新的活性多肽——胰岛素拮抗肽,它在整体和细胞水平上对胰岛素都有明显的拮抗作用。猪胰脏的酸醇提取液经CM-52、BioGel P-6、DEAE-52及RP-HPLC纯化后,可得到纯的胰岛素拮抗肽。它能剂量相关地抑制胰岛素在离体大鼠脂肪细胞中的促脂合成活性,抑制50％胰岛素活性时所需的胰岛素拮抗肽为2.0×10~(-10)mol/L与被拮抗的胰岛素剂量在同一水平上。该肽含有较多的碱性氨基酸,分子量的3 000,其N-末端是封闭的。胰岛素拮抗肽的上述理化特征及其对胰岛素的拮抗活性均不同于目前已知的胰脏活性多肽。它对脂肪细胞中胰岛素的拮抗作用可能具有重要的生理意义。
A new active peptide, insulin antagonist peptide, was purified from the acid-alcohol extract of porcine pancreas and showed significant antagonism of insulin both overall and at cellular level. Purified alcoholic extracts of porcine pancreas were purified by CM-52, BioGel P-6, DEAE-52 and RP-HPLC to obtain pure insulin antagonist peptides. It dose-dependently inhibited the lipotropic activity of insulin in isolated rat adipocytes. The insulin antagonist required to inhibit 50% of the insulin activity was 2.0 × 10 ~ (-10) mol / L and antagonized insulin Dose at the same level. The peptide contains more basic amino acids, with a molecular weight of 3,000, which is blocked at the N-terminus. The above physicochemical properties of the insulin antagonist peptide and its antagonistic activity against insulin are different from currently known pancreatic active polypeptides. Its antagonism of insulin in adipocytes may have important physiological significance.