A Molecular Clamp that Inhibits CRF Amidation

描述（由申请人提供）：大约50%的哺乳动物生物活性肽需要C-末端α-酰胺部分才能获得完整的生物活性。通过C-末端甘氨酸延伸的激素原的氧化裂解产生C-末端酰胺，以产生α-酰胺化肽和乙醛酸。催化该翻译后修饰反应的酶是肽基甘氨酸α-酰胺化单加氧酶（PAM）。由于许多α-酰胺化肽在疾病中发挥的作用，PAM具有作为新的治疗靶点的潜力，例如癌症中的促黄体生成素释放激素（LHRH）和血管活性肠肽（VIP），类风湿性关节炎中的P物质，以及焦虑和抑郁中的促肾上腺皮质激素释放因子（CRF）。PAM的抑制将产生甘氨酸延伸的前体，其效力通常比成熟的α-酰胺化肽低>1000倍。然而，大量已知的哺乳动物α-酰胺化肽（已知约50-100种）意味着特异性靶向PAM的药物可能是高毒性的。在小鼠和果蝇中破坏或消除PAM基因是致命的。因此，PAM作为治疗靶点的潜力仍未开发。我们建议以一种全新的方式解决这个问题-设计分子钳来特异性地阻断单个甘氨酸延伸激素原的酰胺化。这种抗酰胺化分子钳（AM-CLAMP）不会广泛地抑制PAM，因此会回避与肽酰胺化的一般抑制相关的严重毒性问题。

DESCRIPTION (provided by applicant): Approximately 50% of all mammalian bioactive peptides require a C-terminal a-amide moiety for full biological activity. The C-terminal amide is produced by oxidative cleavage of a C-terminal glycine-extended pro-hormone to yield the a-amidated peptide and glyoxylate. The enzyme catalyzing this post-translational modification reaction is peptidylglycine a-amidating monooxygenase (PAM). PAM has potential as a novel therapeutic target as a consequence of the role-played by numerous alpha-amidated peptides in disease, examples being luteinizing hormone-releasing hormone (LHRH) and vasoactive intestinal peptide (VIP) in cancer, substance P in rheumatoid arthritis, and corticotropin-releasing factor (CRF) in anxiety and depression. Inhibition of PAM would generate the glycine-extended precursor that is generally >1000-fold less potent than the mature alpha-amidated peptide. However, the large number of known mammalian alpha-amidated peptides (approximately 50-100 are known) means that a drug specifically targeted against PAM is likely to be highly toxic. Disruption or elimination of the PAM gene in mice and Drosophila is lethal. As a consequence, the potential for PAM as a therapeutic target remains untapped. We propose to solve this problem in a completely new way - with the design of molecular clamp to specifically block the amidation of a single glycine-extend pro-hormone. Such an anti-amidation molecular clamp (AM-CLAMP) would not broadly inhibit PAM and, thus, would side step the serious toxicity problems associated with a general inhibition of peptide amidation.