EQUILIBRIUM AND KINETIC STUDIES OF AGGREGATION OF PORPHYRINS IN AQUEOUS-SOLUTION
EQUILIBRIUM AND KINETIC STUDIES OF AGGREGATION OF PORPHYRINS IN AQUEOUS-SOLUTION
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DOI：
10.1042/bj1530279
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发表时间：
1976-01-01
影响因子：
4.1
通讯作者：
JONES, P
中科院分区：
文献类型：
--
作者：
BROWN, SB;SHILLCOCK, M;JONES, P
研究了原卟啉IX、次卟啉IX、血卟啉IX和粪卟啉III（来自红球藻）在水溶液中的行为，发现了广泛而复杂的聚集过程。原卟啉似乎是高度聚集在所有条件下研究。在低于4 μ M的浓度下，氘-、血红素-和粪卟啉的聚集可能限于二聚化。在约4 μ M时，这3种卟啉中的每一种都表现出与胶束化过程一致的光谱急剧变化，以形成未知尺寸的大聚集体。该临界浓度随温度和pH值的增加而增加，但对离子强度的变化不太敏感。次卟啉的温度跃变动力学研究也意味着一个初始的二聚化过程，其速率常数与各种合成卟啉的速率常数相当，然后进一步广泛的聚集。一个特定的卟啉二聚化的能力似乎平行于相应的Fe（III）络合物（亚铁血红素），虽然它被认为是亚铁血红素不表现出进一步的聚集在这些条件下。
An investigation of the behavior of protoporphyrin IX, deuteroporphyrin IX, hematoporphyrin IX and coproporphyrin III (from Rhodopseudomonas spheroides) in aqueous solution revealed extensive and complex aggregation processes. Protoporphyrin appears to be highly aggregated under all conditions studied. At concentrations below 4 .mu.M aggregation of deutero-, hemato- and coproporphyrin is probably restricted to dimerization. At approximately 4 .mu.M each of these 3 porphyrins exhibits sharp changes in spectra consistent with a micellization process to form large aggregates of unknown size. This critical concentration increases with increasing temperature and pH, but is not very sensitive to variation inionic strength. Temperature-jump kinetic studies on deuteroporphyrin also imply an initial dimerization process, the rate constants for which are comparable with those for various synthetic porphyrins, followed by a further extensive aggregation. The ability of a particular porphyrin to dimerize appears to parallel that of the corresponding Fe(III) complexes (ferrihemes), although it is thought that ferrihemes do not exhibit further aggregation under these conditions.