Harris T K, Mildvan A S
Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Proteins. 1999 May 15;35(3):275-82. doi: 10.1002/(sici)1097-0134(19990515)35:3<275::aid-prot1>3.0.co;2-v.
We have compared hydrogen bond lengths on enzymes derived with high precision (< or = +/- 0.05 A) from both the proton chemical shifts (delta) and the fractionation factors (phi) of the proton involved with those obtained from protein X-ray crystallography. Hydrogen bond distances derived from proton chemical shifts were obtained from a correlation of 59 O--H....O hydrogen bond lengths, measured by small molecule high-resolution X-ray crystallography, with chemical shifts determined by solid-state nuclear magnetic resonance (NMR) in the same crystals (McDermott A, Ridenour CF, Encyclopedia of NMR, Sussex, U.K.: Wiley, 1996:3820-3825). Hydrogen bond distances were independently obtained from fractionation factors that yield distances between the two proton wells in quartic double minimum potential functions (Kreevoy MM, Liang TM, J Am Chem Soc, 1980;102:3315-3322). The high-precision hydrogen bond distances derived from their corresponding NMR-measured proton chemical shifts and fractionation factors agree well with each other and with those reported in protein X-ray structures within the larger errors (+/-0.2-0.8 A) in distances obtained by protein X-ray crystallography. The increased precision in measurements of hydrogen bond lengths by NMR has provided insight into the contributions of short, strong hydrogen bonds to catalysis for several enzymatic reactions.
我们已经比较了通过质子化学位移（δ）和参与的质子的分馏因子（φ）以高精度（≤±0.05 Å）推导得到的酶上的氢键长度，与从蛋白质X射线晶体学获得的氢键长度。由质子化学位移推导得到的氢键距离，是通过将59个O–H....O氢键长度（由小分子高分辨率X射线晶体学测量）与在同一晶体中通过固态核磁共振（NMR）测定的化学位移进行关联得到的（麦克德莫特A，里德努尔CF，《NMR百科全书》，英国苏塞克斯：威利出版社，1996：3820 - 3825）。氢键距离是独立地从分馏因子获得的，这些分馏因子给出了四次双势阱函数中两个质子阱之间的距离（克里沃伊MM，梁TM，《美国化学会志》，1980；102：3315 - 3322）。从其相应的NMR测量的质子化学位移和分馏因子推导得到的高精度氢键距离彼此之间以及与蛋白质X射线结构中报道的距离在蛋白质X射线晶体学获得的距离的较大误差（±0.2 - 0.8 Å）范围内吻合良好。通过NMR测量氢键长度的精度提高，为短而强的氢键对几种酶促反应催化作用的贡献提供了深入了解。
