Hemoglobin senses body temperature
Hemoglobin senses body temperature
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DOI：
10.1007/s00249-009-0410-8
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发表时间：
2009-06-01
影响因子：
2
通讯作者：
Artmann, A. Temiz
中科院分区：
文献类型：
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作者：
Artmann, G. M.;Digel, Ilya;Artmann, A. Temiz
当将人红细胞（RBC）吸入1.3 μ m移液管（Δ P = -2.3 kPa）时，发生从在临界温度T（c）= 36.3 +/- A 0.3A ℃以下阻塞移液管到在T（c）以上通过移液管的转变（微量移液管通过转变）。使用1.1 μ m移液管，未观察到通过，这使得RBC体积测量也高于T（c）。随着温度的升高，RBC在低于T（c）= 36.4 +/- A 0.7（体积转变）时的体积损失明显快于高于T（c）= 36.4 +/- A 0.7（体积转变）。自体血浆中RBC的胶体渗透压（COP）测量（25 A摄氏度a千分之一货币符号T千分之一货币符号39.5A摄氏度）显示T（c）在37.1 +/- A 0.2A摄氏度以上，COP迅速降低（COP转变）。在NMR T（1）-弛豫时间测量中，自体血浆中RBC的T（1）从T（c）= 37 +/- A 1A ℃以下的线性（r = 0.99）增量以0.023 s/K的速率变为T（c）以上的零斜率（RBC T（1）跃迁）。结论：在球形拖尾中形成无定形血红蛋白-水凝胶，即抽吸RBC的残留部分球体。在T（c）时，发生凝胶的突然流化。上述所有变化都发生在接近体温的明显T（c）处。当使用D（2）O缓冲器时，T（c）移动+0.8A ℃至更高的温度。我们提出了一种类似于“玻璃化转变”或“胶体相变”的机制。在T（c）处，稳定化Hb结合水分子达到阈值数目，使得能够部分Hb解折叠。因此，血红蛋白感知体温，而体温必须记录在血红蛋白和其他可能的蛋白质的一级结构中。
When aspirating human red blood cells (RBCs) into 1.3 mu m pipettes (Delta P = -2.3 kPa), a transition from blocking the pipette below a critical temperature T (c) = 36.3 +/- A 0.3A degrees C to passing it above the T (c) occurred (micropipette passage transition). With a 1.1 mu m pipette no passage was seen which enabled RBC volume measurements also above T (c). With increasing temperature RBCs lost volume significantly faster below than above a T (c) = 36.4 +/- A 0.7 (volume transition). Colloid osmotic pressure (COP) measurements of RBCs in autologous plasma (25A degrees C a parts per thousand currency sign T a parts per thousand currency sign 39.5A degrees C) showed a T (c) at 37.1 +/- A 0.2A degrees C above which the COP rapidly decreased (COP transition). In NMR T(1)-relaxation time measurements, the T(1) of RBCs in autologous plasma changed from a linear (r = 0.99) increment below T (c) = 37 +/- A 1A degrees C at a rate of 0.023 s/K into zero slope above T (c) (RBC T(1) transition). In conclusion: An amorphous hemoglobin-water gel formed in the spherical trail, the residual partial sphere of the aspirated RBC. At T (c), a sudden fluidization of the gel occurs. All changes mentioned above happen at a distinct T (c) close to body temperature. The T (c) is moved +0.8A degrees C to higher temperatures when a D(2)O buffer is used. We suggest a mechanism similar to a "glass transition" or a "colloidal phase transition". At T (c), the stabilizing Hb bound water molecules reach a threshold number enabling a partial Hb unfolding. Thus, Hb senses body temperature which must be inscribed in the primary structure of hemoglobin and possibly other proteins.