CRYSTAL VERSUS SOLUTION STRUCTURE OF ENZYMES - NMR-SPECTROSCOPY OF A PEPTIDE BORONIC ACID-SERINE PROTEASE COMPLEX IN THE CRYSTALLINE STATE
CRYSTAL VERSUS SOLUTION STRUCTURE OF ENZYMES - NMR-SPECTROSCOPY OF A PEPTIDE BORONIC ACID-SERINE PROTEASE COMPLEX IN THE CRYSTALLINE STATE
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DOI：
10.1073/pnas.86.18.6922
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发表时间：
1989-09-01
影响因子：
11.1
通讯作者：
BACHOVCHIN, WW
中科院分区：
文献类型：
--
作者：
FARRJONES, S;SMITH, SO;BACHOVCHIN, WW
硼酸作为丝氨酸蛋白酶抑制剂的有效性已被广泛归因于硼酰基与活性位点丝氨酸形成四面体加合物的能力，所述四面体加合物紧密模拟与底物形成的推定四面体中间体或过渡态。然而，最近的α-NMR研究表明，溶解性蛋白酶（EC 3.4.21.12）的研究表明，某些硼酸和肽硼酸与活性位点组氨酸而不是丝氨酸形成加合物。这种组氨酸硼加合物迄今尚未报道在硼酸丝氨酸蛋白酶复合物的X-射线衍射研究。在此，我们报告了α-MeOSuc-Ala-Ala-Pro-boroPhe复合物的15 N NMR研究。使用魔角旋转法获得结晶态的溶解蛋白酶。以前的15 N NMR研究表明，这种复合物涉及在溶液中形成组氨酸-硼键。结晶络合物的15 N NMR光谱与溶液中络合物的15 N NMR光谱基本相同，从而表明该络合物的结构在溶液中和晶体中相同，并且两者都涉及组氨酸-硼加合物的形成。
The effectiveness of boronic acids as inhibitors of serine proteases has been widely ascribed to the ability of the boronyl group to form a tetrahedral adduct with the active-site serine that closely mimics the putative tetrahedral intermediate or transition state formed with substrates. However, recent 15N NMR studies of .alpha.-lytic protease (EC 3.4.21.12) in solution have shown that some boronic acids and peptide boronic acids form adducts with the active-site histidine instead of with the serine. Such histidine-boron adducts have not thus far been reported in x-ray diffraction studies of boronic acid-serine protease complexes. Here, we report an 15N NMR study of the MeOSuc-Ala-Ala-Pro-boroPhe complex of .alpha.-lytic protease in the crystalline state using magic-angle spinning. Previous 15N NMR studies have shown this complex involves the formation of a histidine-boron bond in solution. The 15N NMR spectra of the crystalline complex are essentially identical to those of the complex in solution, thereby showing that the structure of this complex is the same in solution and in the crystal and that both involve formation of a histidine-boron adduct.