Koppisetti Rama K, Fulcher Yan G, Jurkevich Alexander, Prior Stephen H, Xu Jia, Lenoir Marc, Overduin Michael, Van Doren Steven R
Department of Biochemistry, University of Missouri, 117 Schweitzer Hall, Columbia, Missouri 65211, USA.
Molecular Cytology Core, 120 Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, USA.
Nat Commun. 2014 Nov 21;5:5552. doi: 10.1038/ncomms6552.
Matrix metalloproteinases (MMPs) regulate tissue remodelling, inflammation and disease progression. Some soluble MMPs are inexplicably active near cell surfaces. Here we demonstrate the binding of MMP-12 directly to bilayers and cellular membranes using paramagnetic NMR and fluorescence. Opposing sides of the catalytic domain engage spin-labelled membrane mimics. Loops project from the β-sheet interface to contact the phospholipid bilayer with basic and hydrophobic residues. The distal membrane interface comprises loops on the other side of the catalytic cleft. Both interfaces mediate MMP-12 association with vesicles and cell membranes. MMP-12 binds plasma membranes and is internalized to hydrophobic perinuclear features, the nuclear membrane and inside the nucleus within minutes. While binding of TIMP-2 to MMP-12 hinders membrane interactions beside the active site, TIMP-2-inhibited MMP-12 binds vesicles and cells, suggesting compensatory rotation of its membrane approaches. MMP-12 association with diverse cell membranes may target its activities to modulate innate immune responses and inflammation.
基质金属蛋白酶（MMPs）调节组织重塑、炎症和疾病进展。一些可溶性MMPs在细胞表面附近具有难以解释的活性。在这里，我们使用顺磁核磁共振和荧光技术证明了MMP-12直接与双层膜和细胞膜结合。催化结构域的相对两侧与自旋标记的膜模拟物结合。环从β-折叠界面伸出，通过碱性和疏水残基与磷脂双层接触。远端膜界面由催化裂隙另一侧的环组成。两个界面都介导MMP-12与囊泡和细胞膜的结合。MMP-12结合质膜，并在几分钟内内化到疏水的核周结构、核膜和细胞核内。虽然TIMP-2与MMP-12的结合会阻碍活性位点旁边的膜相互作用，但TIMP-2抑制的MMP-12仍能结合囊泡和细胞，这表明其膜结合方式发生了补偿性旋转。MMP-12与多种细胞膜的结合可能将其活性靶向于调节先天免疫反应和炎症。
