Controllable Electrocatalytic Activity of Heme Peptide in a Phase Transition Gel
Controllable Electrocatalytic Activity of Heme Peptide in a Phase Transition Gel
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相变凝胶中血红素肽的可控电催化活性
DOI：
10.1149/1.1391125
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发表时间：
1999
影响因子：
--
通讯作者：
N. Oyama
中科院分区：
文献类型：
--
作者：
T. Tatsuma;Y. Fujimoto;N. Oyama
将N-异丙基丙烯酰胺基相变凝胶涂覆在电极表面，并将血红素肽作为过氧化物酶模型化合物共价包埋在凝胶中。凝胶对H_2O_2电还原的表观催化活性受凝胶溶胀（≤ 30 ℃）和收缩（≥ 40 ℃）的控制，收缩的凝胶表现出较高的表观催化活性。血红素肽在溶胀凝胶中形成的微氧代二聚体或低聚体，以及由于血红素肽分子的低迁移率和空间位阻而在收缩凝胶中的解离，可能是活性变化的原因。作为与含有氯化血红素代替血红素肽的类似凝胶的比较的结果，发现活性位点的亲水性或疏水性可能严重影响催化活性的温度依赖性。
A phase transition gel based on N-isopropylacrylamide was coated on the electrode surface, and heme peptide as a peroxidase model compound was covalently entrapped in the gel. Apparent catalytic activity of the gel for H2O2 electroreduction was controlled by swelling (≤ 30 C) and shrinking (≥ 40 C) the gel; the shrunken gel exhibited higher apparent activity. Formation of the µ-oxo dimer, or oligomers of heme peptide in the swollen gel and the dissociation in the shrunken gel due to low mobility of heme peptide molecules and steric hindrance, may be responsible for the activity changes. As a result of the comparison with a similar gel containing hemin in place of the heme peptide, it was found that hydrophilicity or hydrophobicity of the active site may affect critically the temperature-dependence of the catalytic activity.