IMMUNOLOGY & DISEASES OF THE GASTROINTESTINAL TRACT

本研究针对胃肠病的研究提出建议。 特别强调与其相互作用的调节肽 受体及其结构和功能的表征 这些调节作用的细胞受体膜蛋白的特性 多肽。与胃肠调节多肽互补的多肽 将通过基于信使核糖核酸的固相法合成多肽 与人胃泌素I(G17)的密码子互补，羧基- 末端胃泌素四肽(G4)，其羧基末端八肽 CCK8、生长抑素14(S14)及其羧基末端 胃泌素释放肽十四肽(GRP14)。配基结合 这些互补多肽的性质将被评估为 ~(125)I-胃肠调节多肽的孵育 聚氯乙烯微孔中的胃肠调节多肽 涂有各自互补多肽的平板。竞争 将进行研究以评估125I-结合的特异性 调节多肽。针对互补多肽的抗体将是 用互补多肽免疫兔所产生的 与锁孔帽状血蓝蛋白偶联为载体蛋白。潜力 这些抗体的结合，将通过免疫亲和力进行纯化 125I标记的细胞膜受体的层析和放射性标记 (胃粘膜壁细胞、胃泌素细胞和生长抑素细胞) 将会被检查。细胞将从犬的胃底粘膜中制备出来 胶原酶解离后进行淋洗。抗病毒抗体 互补多肽，预计与膜的结合部位结合 受体蛋白将用于免疫亲和力研究，以纯化 胃泌素、生长抑素和胃泌素释放的细胞膜受体 多肽，以确定这些膜受体的结构。 初步研究将针对膜的表征 胃泌素受体。在拟议研究的后期阶段， 应用上述技术研究犬的胃底粘膜 细胞，还将进行实验以检查结构和 胃泌素瘤细胞膜受体的功能特性 胃泌素释放肽和生长抑素。

This research proposal is directed to the study of gastrointestinal regulatory peptides with special emphasis on interactions with their receptors as well as characterization of structure and functional characteristics of cell receptor membrane proteins for these regulatory peptides. Peptides complementary to gastrointestinal regulatory peptides will be synthesized by solid phase peptide synthesis based on mRNA complementarity to the codons of human gastrin I (G17), the carboxyl- terminal gastrin tetrapeptide (G4), the carboxyl-terminal octapeptide of cholecystokinin (CCK8), somatostatin-14 (S14) and the carboxyl-terminal tetradecapeptide of gastrin-releasing peptide (GRP14). Ligand binding properties of these complementary peptides will be assessed for the respective gastrointestinal regulatory peptides by incubation of 125 I- gastrointestinal regulatory peptides in wells of polyvinyl chloride plates coated with the respective complementary peptides. Competition studies will be performed to assess specificity of binding of 125 I- regulatory peptides. Antibodies to complementary peptides will be produced by immunization of rabbits with complementary peptides conjugated to keyhole limpet hemocyanin as carrier protein. Potential binding of these antibodies, which will be purified by immunoaffinity chromatography and radiolabelled with 125 I, to cell membrane receptors (on gastric mucosal parietal cells, gastrin cells and somatostatin cells) will be examined. Cells will be prepared from canine fundic mucosa by collagenase dissociation followed by elutriation. Antibodies to complementary peptides, anticipated to bind to binding sites of membrane receptor proteins will be utilized in immunoaffinity studies to purify cell membrane receptors for gastrin, somatostatin, and gastrin-releasing peptide in order to determine the structure of those membrane receptors. Initial studies will be directed to characterization of membrane receptors for gastrin. In the later stages of the proposed studies, using techniques as described for the study of canine fundic mucosal cells, experiments will also be performed to examine structural and functional characteristics of gastrinoma cell membrane receptors for gastrin-releasing peptide and somatostatin.