Christensen A M, Schaefer J
Department of Chemistry, Washington University, St. Louis, Missouri 63130.
Biochemistry. 1993 Mar 23;32(11):2868-73. doi: 10.1021/bi00062a018.
Rotational-echo, double-resonance (REDOR) 31P NMR was used to obtain internuclear distances for shikimate 3-phosphate (S3P) and N-(phosphonomethyl)-[1-13C]glycine (glyphosate) bound to 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, a 46-kDa enzyme essential for the synthesis of aromatic amino acids in plants and microorganisms. An intermolecular 31P-13C distance of 7.2 A was measured between the phosphate of S3P and the labeled carbon of glyphosate. This means that S3P and glyphosate are in proximity in the binding site of the enzyme. An intramolecular 31P-13C distance of 5.6 A was measured between the phosphonate 31P and the labeled carbon of glyphosate. This distance can be achieved only if glyphosate is completely extended when bound to EPSP synthase.
旋转回波双共振（REDOR）31P核磁共振技术被用于测定与5-烯醇式丙酮酸莽草酸-3-磷酸合酶（EPSP合酶）结合的莽草酸-3-磷酸（S3P）和N-（膦酰甲基）-[1-13C]甘氨酸（草甘膦）的核间距离，EPSP合酶是一种46 kDa的酶，对植物和微生物中芳香族氨基酸的合成至关重要。在S3P的磷酸基团和草甘膦的标记碳之间测得分子间31P-13C距离为7.2 Å。这意味着S3P和草甘膦在酶的结合位点处相互靠近。在草甘膦的膦酸酯31P和标记碳之间测得分子内31P-13C距离为5.6 Å。只有当草甘膦与EPSP合酶结合时完全伸展，才能达到这个距离。
