光调控酶变构通过光响应非天然氨基酸。
Light Regulation of Enzyme Allostery through Photo-responsive Unnatural Amino Acids.
机构信息
Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
Institute of Organic Chemistry, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
出版信息
Cell Chem Biol. 2019 Nov 21;26(11):1501-1514.e9. doi: 10.1016/j.chembiol.2019.08.006. Epub 2019 Sep 5.
Imidazole glycerol phosphate synthase (ImGPS) is an allosteric bienzyme complex in which substrate binding to the synthase subunit HisF stimulates the glutaminase subunit HisH. To control this stimulation with light, we have incorporated the photo-responsive unnatural amino acids phenylalanine-4'-azobenzene (AzoF), o-nitropiperonyl-O-tyrosine (NPY), and methyl-o-nitropiperonyllysine (mNPK) at strategic positions of HisF. The light-mediated isomerization of AzoF at position 55 (fS55AzoF ↔ fS55AzoF) resulted in a reversible 10-fold regulation of HisH activity. The light-mediated decaging of NPY at position 39 (fY39NPY → fY39) and of mNPK at position 99 (fK99mNPK → fK99) led to a 4- to 6-fold increase of HisH activity. Molecular dynamics simulations explained how the unnatural amino acids interfere with the allosteric machinery of ImGPS and revealed additional aspects of HisH stimulation in wild-type ImGPS. Our findings show that unnatural amino acids can be used as a powerful tool for the spatiotemporal control of a central metabolic enzyme complex by light.
咪唑甘油磷酸合酶（ImGPS）是一种变构双酶复合物，其中底物与合酶亚基 HisF 的结合刺激谷氨酰胺酶亚基 HisH。为了用光来控制这种刺激，我们在 HisF 的关键位置引入了光响应的非天然氨基酸苯丙氨酸-4'-偶氮苯（AzoF）、邻硝基胡椒基-O-酪氨酸（NPY）和甲基-O-硝基胡椒基赖氨酸（mNPK）。位置 55 的 AzoF 的光诱导异构化（fS55AzoF↔fS55AzoF）导致 HisH 活性的可逆 10 倍调节。位置 39 的 NPY 的光去封端（fY39NPY→fY39）和位置 99 的 mNPK 的光去封端（fK99mNPK→fK99）导致 HisH 活性增加 4 到 6 倍。分子动力学模拟解释了非天然氨基酸如何干扰 ImGPS 的变构机制，并揭示了野生型 ImGPS 中 HisH 刺激的其他方面。我们的发现表明，非天然氨基酸可用作通过光对中央代谢酶复合物进行时空控制的强大工具。
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