Identification and characterization of desacyl-ghrelin

胃饥饿素是一种调节食欲的肽激素，已知有两种形式（乙酰胃饥饿素和去乙酰胃饥饿素）。Ghrelin受体（GHSR）识别翻译后酰基修饰，在多种组织中表达。然而，没有脂质修饰的胃饥饿素不与GHSR结合，并对酰基胃饥饿素起拮抗作用。这些发现提示存在未知的去酰基胃饥饿素特异性受体。利用猪脑提取物对去酰基胃饥饿素结合蛋白进行亲和纯化。我们尝试在高盐条件下（1M NaCl）洗脱去酰基胃饥饿素相关蛋白，但未检测到候选分子的明显缩聚。接下来，我们使用转染了亚池小鼠脑cDNA文库的COS7细胞进行常规受体筛选实验。我们发现了几个“阳性池”，克隆程序的进一步选择正在进行中。

Ghrelin is a peptide hormone to regulate appetite and is known to have two forms (acyl ghrelin and des-acyl ghrelin). Ghrelin receptor (GHSR), which recognizes the post-translational acyl-modification, expressed in various tissues. However, ghrelin without lipid-modification does not bind to GHSR and functions antagonistic to acyl ghrelin. These findings suggested the presenceof unknown receptor specific for des-acyl ghrelin. We performed affinity-purification of des-acyl ghrelin-binding protein using pig brain extract. We tried to elute des-acyl ghrelin-associated protein by high salt condition (1M NaCl) but detected no significant condensation of candidate molecules. Next, we performed conventional receptor panning assay using COS7 cells transfected with sub-pooled mouse brain cDNA libraries. We detected several pools as “positive pools” and further selection of procedures for cloning is in process.