Lin K c, Ateeq H S, Hsiung S H, Chong L T, Zimmerman C N, Castro A, Lee W C, Hammond C E, Kalkunte S, Chen L L, Pepinsky R B, Leone D R, Sprague A G, Abraham W M, Gill A, Lobb R R, Adams S P
Biogen Inc., 12 Cambridge Center, Cambridge, Massachusetts 02142, and Mount Sinai Medical Center, Miami Beach, Florida 33140, USA.
J Med Chem. 1999 Mar 11;42(5):920-34. doi: 10.1021/jm980673g.
Integrin alpha4beta1 mediates leukocyte recruitment, activation, mediator release, and apoptosis inhibition, and it plays a central role in inflammatory pathophysiology. High-affinity, selective inhibitors of alpha4beta1, based on the Leu-Asp-Val (LDV) sequence from the alternatively spliced connecting segment-1 (CS-1) peptide of cellular fibronectin, are described that employ a novel N-terminal peptide "cap" strategy. One inhibitor, BIO-1211, was approximately 10(6)-fold more potent than the starting peptide and exhibited tight-binding properties (koff = 1.4 x 10(-4) s-1, KD = 70 pM), a remarkable finding for a noncovalent, small-molecule inhibitor of a protein receptor. BIO-1211 was also 200-fold selective for the activated form of alpha4beta1, and it stimulated expression of ligand-induced epitopes on the integrin beta1 subunit, a property consistent with occupancy of the receptor's ligand-binding site. Pretreatment of allergic sheep with a 3-mg nebulized dose of BIO-1211 inhibited early and late airway responses following antigen challenge and prevented development of nonspecific airway hyperresponsiveness to carbachol. These results show that highly selective and potent small-molecule antagonists can be identified to integrins with primary specificity for peptide domains other than Arg-Gly-Asp (RGD); they confirm the generality of integrins as small molecule targets; and they validate alpha4beta1 as a therapeutic target for asthma.
整合素α4β1介导白细胞募集、激活、介质释放及凋亡抑制，在炎症病理生理学中起核心作用。本文描述了基于细胞纤连蛋白可变剪接连接段-1（CS-1）肽的Leu-Asp-Val（LDV）序列的高亲和力、选择性α4β1抑制剂，其采用了一种新型的N端肽“帽”策略。一种抑制剂BIO-1211的效力比起始肽高约10^6倍，并表现出紧密结合特性（解离速率常数koff = 1.4×10^-4 s^-1，解离常数KD = 70 pM），这对于一种蛋白质受体的非共价小分子抑制剂来说是一个显著发现。BIO-1211对激活形式的α4β1也具有200倍的选择性，并且它刺激整合素β1亚基上配体诱导表位的表达，这一特性与受体配体结合位点的占据情况一致。用3毫克雾化剂量的BIO-1211预处理过敏绵羊，可抑制抗原激发后的早期和晚期气道反应，并预防对卡巴胆碱的非特异性气道高反应性的发展。这些结果表明，可以鉴定出对除精氨酸-甘氨酸-天冬氨酸（RGD）以外的肽结构域具有主要特异性的整合素的高选择性和强效小分子拮抗剂；它们证实了整合素作为小分子靶点的普遍性；并且它们验证了α4β1作为哮喘治疗靶点的有效性。
