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-Structure paper
タイトル | Allosteric inhibition of HTRA1 activity by a conformational lock mechanism to treat age-related macular degeneration. |
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ジャーナル・号・ページ | Nat Commun, Vol. 13, Issue 1, Page 5222, Year 2022 |
掲載日 | 2022年9月5日 |
著者 | Stefan Gerhardy / Mark Ultsch / Wanjian Tang / Evan Green / Jeffrey K Holden / Wei Li / Alberto Estevez / Chris Arthur / Irene Tom / Alexis Rohou / Daniel Kirchhofer / |
PubMed 要旨 | The trimeric serine protease HTRA1 is a genetic risk factor associated with geographic atrophy (GA), a currently untreatable form of age-related macular degeneration. Here, we describe the allosteric ...The trimeric serine protease HTRA1 is a genetic risk factor associated with geographic atrophy (GA), a currently untreatable form of age-related macular degeneration. Here, we describe the allosteric inhibition mechanism of HTRA1 by a clinical Fab fragment, currently being evaluated for GA treatment. Using cryo-EM, X-ray crystallography and biochemical assays we identify the exposed LoopA of HTRA1 as the sole Fab epitope, which is approximately 30 Å away from the active site. The cryo-EM structure of the HTRA1:Fab complex in combination with molecular dynamics simulations revealed that Fab binding to LoopA locks HTRA1 in a non-competent conformational state, incapable of supporting catalysis. Moreover, grafting the HTRA1-LoopA epitope onto HTRA2 and HTRA3 transferred the allosteric inhibition mechanism. This suggests a conserved conformational lock mechanism across the HTRA family and a critical role of LoopA for catalysis, which was supported by the reduced activity of HTRA1-3 upon LoopA deletion or perturbation. This study reveals the long-range inhibition mechanism of the clinical Fab and identifies an essential function of the exposed LoopA for activity of HTRA family proteases. |
リンク | Nat Commun / PubMed:36064790 / PubMed Central |
手法 | EM (単粒子) / X線回折 |
解像度 | 1.8 - 3.4 Å |
構造データ | EMDB-25162, PDB-7sjn: EMDB-25163, PDB-7sjo: PDB-7sjm: PDB-7sjp: |
化合物 | ChemComp-SO4: ChemComp-GOL: ChemComp-HOH: |
由来 |
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キーワード | IMMUNE SYSTEM / Fab / HYDROLASE/Immune System / HtrA1 / allosteric inhibition / Age-related macular degeneration / Geographic Atrophy / Antibody complex / HYDROLASE / HYDROLASE-Immune System complex / Fab Htra 1 peptide complex |