Abstract The interactions of divalent metal ions with several normal biological buffers, such as 2-(N-morpholino)ethane sulfonic acid (MES), 3-(N-morpholino)propane sulfonic acid (MOPS), 4-(2-hydroxyethyl)-1-piperazineethane sulfonic acid (HEPES), tris(hydroxymethyl)aminomethane (Tris) and N-[tris(hydroxymethyl)methyl]-2-aminoethanesulfonic acid (TES) have been investigated by using isothermal titration calorimetry (ITC) from the calorimetric perspective. MES at pH 6.0 does not form complexes with Zn2+, Cd2+, Ca2+, Co2+, Mg2+, Mn2+, and Ni2+, and shows imperceptible complexation ability to Cu2+ and Pb2+. MOPS and HEPES at pH 7.4 show no binding affinity to Ca2+, Co2+, Mg2+, Mn2+, and Ni2+, mild binding affinity towards Cu2+ and Pb2+, and weak binding affinity to Zn2+ and Cd2+. The metal complexation abilities of Tris are much stronger than MOPS or HEPES, especially towards Cu2+ and Pb2+. TES shows negligible binding affinity to Zn2+, Cd2+, Ca2+, Co2+, Mg2+, Mn2+, and Ni2+, and a moderate binding affinity towards Cu2+.

中文翻译：

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二价金属离子与几种生物缓冲液的结合热力学

摘要 二价金属离子与几种常规生物缓冲液的相互作用，如 2-(N-吗啉) 乙磺酸 (MES)、3-(N-吗啉) 丙磺酸 (MOPS)、4-(2-羟乙基) -1-哌嗪乙烷磺酸 (HEPES)、三(羟甲基)氨基甲烷 (Tris) 和 N-[三(羟甲基)甲基]-2-氨基乙磺酸 (TES) 已通过使用等温滴定量热法 (ITC) 从量热法看法。MES 在 pH 6.0 下不与 Zn2+、Cd2+、Ca2+、Co2+、Mg2+、Mn2+ 和 Ni2+ 形成络合物，并且对 Cu2+ 和 Pb2+ 表现出难以察觉的络合能力。在 pH 7.4 下 MOPS 和 HEPES 对 Ca2+、Co2+、Mg2+、Mn2+ 和 Ni2+ 没有结合亲和力，对 Cu2+ 和 Pb2+ 有温和的结合亲和力，对 Zn2+ 和 Cd2+ 的结合亲和力弱。Tris 的金属络合能力比 MOPS 或 HEPES 强得多，尤其是对 Cu2+ 和 Pb2+。TES 对 Zn2+、Cd2+、Ca2+、Co2+、Mg2+、Mn2+ 和 Ni2+ 的结合亲和力可以忽略不计，而对 Cu2+ 的结合亲和力中等。