1H NMR relaxation measurements in highly concentrated water protein solutions
1H NMR relaxation measurements in highly concentrated water protein solutions
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DOI：
10.1002/(sici)1097-458x(199912)37:13
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发表时间：
1999-12-01
影响因子：
2
通讯作者：
Gutsze, A
中科院分区：
文献类型：
--
作者：
Olechnowicz, R;Masierak, W;Gutsze, A
对生物系统（例如植物、种子和动物的部分）进行的测量揭示了自旋-自旋弛豫函数的非指数衰减。在眼睛晶状体中也观察到了这种行为，这是一个相对简单的系统，主要由占总重量 65% 的水和 35% 的有机材料（主要是结构蛋白）构成。为了理解这一现象，我们必须找到一种简化的系统，该系统可以测量和描述磁弛豫过程，并将其与生物系统进行比较。一种这样的系统可以是浓度高于30%的牛血清白蛋白（BSA）的水溶液。研究发现，低浓度白蛋白水溶液中的核磁弛豫时间T-2主要取决于自由水与蛋白质表面吸附水之间的快速质子交换。对于较高浓度的 BSA (30%-55%)，第二个质子交换过程开始发挥作用，因此自旋-自旋弛豫函数是两个指数函数的总和。版权所有 (C) 1999 John Wiley & Sons, Ltd.
Measurements performed on biological systems, such as parts of plants, seeds and animals reveal non-exponential decay of the spin-spin relaxation function. Such behaviour has also been observed in the eye lens, which is a relative simple system mainly built from water, 65% of total weight, and 35% organic material, mainly structural proteins. To understand this phenomena one has to find a simplified system which will allow measurement and description of magnetic relaxation processes and compare them to the biological system. One such system can be water solution of bovine serum albumin (BSA) with concentration higher than 30%. It was found that nuclear magnetic relaxation time, T-2, in aqueous solution of albumin for low concentration depends mainly on fast proton exchange between free water and water adsorbed on the protein surface. For higher concentration of BSA (30%-55%) a second proton exchange process starts to play a role and in consequence the spin-spin relaxation function is a sum of two exponential functions. Copyright (C) 1999 John Wiley & Sons, Ltd.