Preparation of metal ion buffers for biological experimentation: A methods approach with emphasis on iron and zinc
Preparation of metal ion buffers for biological experimentation: A methods approach with emphasis on iron and zinc
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DOI：
10.1002/jez.10068
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发表时间：
2002-05-01
影响因子：
--
通讯作者：
Ahearn, GA
中科院分区：
文献类型：
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作者：
Aslamkhan, AG;Aslamkhan, A;Ahearn, GA
过渡金属离子在生理学研究中是一个挑战，因为与溶解度，氧化，结合，并在溶液中获得适当的自由活动相关的问题。本文讨论了这些问题和解决这些问题的可能途径。特别注意的是铁和锌离子，但许多概念可以应用于研究其他过渡金属。本文简要讨论了金属加工用试剂（包括水、盐、非络合pH缓冲剂）的选择。涵盖了常见铁和锌沉淀物的溶度积（K-sp）的计算，以及用于用有机螯合物溶解Fe 3+的技术。提到影响Fe 2+氧化的因素，并考虑使用抗坏血酸作为还原剂。本文还讨论了用Fe ~（2+）发色团ferrozine和BPS测定Fe ~（2+）氧化（或Fe ~（3+）还原）速率的方法。讨论了通过使用金属缓冲剂（螯合剂）产生游离金属离子活性。与此技术相关的理论问题进行了探讨，并选择共享金属离子缓冲计算器进行说明。最后，被认为是用于测量和减少铁和锌离子的生物膜非特异性结合的技术。J. Exp. Zool.292：507-522，2002. (C)2002 Wiley-Liss，Inc.
Transition metal ions are a challenge to study in physiology because of problems associated with solubility, oxidation, binding, and attaining appropriate free activities in solution. This review discusses these problems and potential ways of accommodating them. Special attention is given to iron and zinc ions, but many of the concepts can be applied for studying other transition metals. Selection of reagents appropriate for metal work (including water, salts, noncomplexing pH buffers) is briefly discussed. Calculation of the solubility product (K-sp) for common iron and zinc precipitates is covered, as well as techniques used to solubilize Fe3+ with organic chelates. Factors that affect Fe2+ oxidation are mentioned, and the use of ascorbate as a reducing agent is considered. Measurement of the rate of Fe2+ oxidation (or Fe3+ reduction) with the Fe2+ chromophores ferrozine and BPS is also discussed. Generation of a free metal ion activity through use of metal buffers (chelators) is discussed. Theoretical problems associated with this technique are explored, and selected shareware metal ion buffer calculators are described. Finally, techniques for measuring and minimizing nonspecific binding of iron and zinc ions to biological membranes are considered. J. Exp. Zool. 292:507-522, 2002. (C) 2002 Wiley-Liss, Inc.