Chair of Bioinorganic Chemistry, Department of Chemistry and Pharmacy, University Erlangen-Nürnberg, Egerlandstr. 1, 91058 Erlangen, Germany.
J Inorg Biochem. 2012 Apr;109:26-32. doi: 10.1016/j.jinorgbio.2011.12.008. Epub 2011 Dec 29.
Stopped-flow measurements have been successfully combined with time-resolved UV/vis spectroscopy and global spectral analysis of superoxide decay for the comparative study of catalytic activity of putative manganese SOD (superoxide dismutase) mimetics known in the literature. The SOD activity of the studied complexes decreases in the following order: a) M40403>Mn(III)TM-4-PyP(5+)>Mn(II)pyane >>EUK-113 at pH 7.4 (M40403=([manganese(II)dichlorido{(4R,9R,14R,19R)-3,10,13,20,26-pentaazatetracyclo[20.3.1.0.4,9014,19]hexacosa-1(26),-22(23),24-triene}], Mn(III)TM-4-PyP(5+)=Mn(III)meso-tetrakis(N-methylpyridinium-4-yl)porphyrin, Mn(II)Pyane=Mn(II)trans-2,13-dimethyl-3,6,9,12,18-pentaazabicyclo[12.3.1]-octadeca-1(18),14,16-triene, EUK-113=[manganese(III)acetato(6,6'-((1E,1'E)-(ethane-1,2-diylbis(azanylylidene))bis(methanylylidene))bis(2-methoxyphenolate)]) in Hepes buffer (Hepes=4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid), b) Mn(III)TM-4-PyP(5+)>M40403≅Mn(II)pyane >>EUK-113 at pH 8.1 in Hepes buffer and c) Mn(III)TM-4-PyP(5+)≅Mn(II)pyane>MnCl(2)>M40403≅EUK-113 at pH 7.4 in phosphate buffer. MnCl(2) in Hepes, Mn(III)TSPP(3-), Mn(III)TBAP(3-), Mn(III)acetate, Mn(II)lactate and Mn(II)EDTA do not exhibit SOD activity (Mn(III)TSPP(3-)=Mn(III)mesotetrakis(benzoic acid)porphyrin, Mn(III)TBAP(3-)=Mn(III)mesotetrakis(4-sulfonatophenyl)porphyrin). MnCl(2) possess SOD activity that is comparable with those of other mimetics in the presence of phosphate. Our results demonstrate that phosphate anions, independent of ionic strength effect, influence the activity of manganese SOD mimetics, which is crucial for understanding and comparing their biological activity.
停流测量已成功与时间分辨的紫外/可见光谱和超氧化物衰减的全局光谱分析相结合，用于比较文献中已知的假定锰 SOD（超氧化物歧化酶）模拟物的催化活性。研究复合物的 SOD 活性按以下顺序降低：a）M40403>Mn（III）TM-4-PyP（5+）>Mn（II）pyane>>EUK-113，在 pH 7.4 时（M40403=[（锰（II）二氯化物{(4R，9R，14R，19R)-3，10，13，20，26-五氮杂环二十烷-1（26），-22（23），24-三烯}]，Mn（III）TM-4-PyP（5+）=Mn（III）meso-四（N-甲基吡啶-4-基）卟啉，Mn（II）Pyane=Mn（II）反式-2,13-二甲基-3,6,9,12,18-五氮杂环十八烷-1（18），14,16-三烯，EUK-113=[锰（III）乙酸盐（6,6'-（1E，1'E）-（乙烷-1,2-二基双（氮杂基）双（甲叉基））双（2-甲氧基苯酚）]）在 Hepes 缓冲液（Hepes=4-（2-羟乙基）哌嗪-1-乙磺酸），b）Mn（III）TM-4-PyP（5+）>M40403≅Mn（II）pyane>>EUK-113，在 Hepes 缓冲液 pH8.1 时，c）Mn（III）TM-4-PyP（5+）≅Mn（II）pyane>MnCl（2）>M40403≅EUK-113，在 Hepes 缓冲液中在 pH7.4 时在磷酸盐缓冲液中。MnCl（2）在 Hepes 中，Mn（III）TSPP（3-），Mn（III）TBAP（3-），Mn（III）乙酸盐，Mn（II）乳酸盐和 Mn（II）EDTA 均不表现出 SOD 活性（Mn（III）TSPP（3-）=Mn（III）meso-四（苯甲酸）卟啉，Mn（III）TBAP（3-）=Mn（III）meso-四（4-磺基苯）卟啉）。在磷酸盐存在下，MnCl（2）具有与其他模拟物相当的 SOD 活性。我们的结果表明，磷酸盐阴离子，独立于离子强度的影响，影响锰 SOD 模拟物的活性，这对于理解和比较它们的生物学活性至关重要。
