Department of Physiology and Biophysics, Gifu University Graduate School of Medicine, Gifu, Japan.
NMR Biomed. 2011 Jun;24(5):483-91. doi: 10.1002/nbm.1612. Epub 2011 Jan 28.
Intermolecular cross-relaxation rate (CR) spectra [1/T(IS) (HDO) or 1/T(IS) (H(2) O) vs f(2) (ppm) profiles] for bovine serum albumin [BSA; molecular weight (MW), 66 kDa] solution, partially hydrolyzed BSA gel (BSAgel) and packed human red blood cells (RBCs) with normal or unstable hemoglobin (Hb; MW, 65 kDa) were studied using f(2) irradiation ranging from - 100 to 100 ppm at γH(2) /2π of 250 Hz. The CR spectra for BSAgel (pD 4.01, 0.10 M NaCl, 4.83 and 14.39%) exhibited different features in the off-resonance region (below - 2.00 and above 12.0 ppm) relative to that for BSA solution (pD 7.14, 0.10 M NaCl, 14.39%), indicating the association of BSA* molecules in the gel state. The CR spectrum for packed RBCs was compared with those for BSA*gel and BSA solution (14.39%) by correcting for differences in protein concentration. The corrected CR spectrum for packed normal RBCs in the off-resonance region was similar to that for BSA solution, indicating that the physical characteristics of Hb in normal RBCs may be in a solution-like state. Our results on normal RBCs were approximately consistent with the previously reported thermodynamic and hydrodynamic findings that Hb in RBCs and/or in concentrated solution seems to be in a suspension of hard scaled particles.
采用 f2 照射，γH2/2π为 250 Hz，研究了牛血清白蛋白（BSA；分子量（MW），66 kDa）溶液、部分水解的 BSA 凝胶（BSA凝胶）和具有正常或不稳定血红蛋白（Hb；MW，65 kDa）的人红细胞（RBC）的分子间交叉弛豫率（CR）谱[1/T（IS）（HDO）或 1/T（IS）（H2O）与 f2（ppm）谱]。BSA凝胶（pD 4.01，0.10 M NaCl，4.83 和 14.39%）的 CR 谱在离共振区（低于-2.00 和高于 12.0 ppm）与 BSA 溶液（pD 7.14，0.10 M NaCl，14.39%）的特征不同，表明 BSA分子在凝胶状态下的缔合。通过校正蛋白质浓度的差异，将包装 RBCs 的 CR 谱与 BSA凝胶和 BSA 溶液（14.39%）的 CR 谱进行了比较。在离共振区，校正后包装正常 RBCs 的 CR 谱与 BSA 溶液的 CR 谱相似，表明正常 RBCs 中 Hb 的物理特性可能处于溶液状态。我们对正常 RBCs 的研究结果与先前报道的热力学和流体力学发现大致一致，即 RBCs 中的 Hb 和/或浓缩溶液中的 Hb 似乎处于悬浮硬壳颗粒的状态。
