Nozawa T, Kobayashi N, Hatano M
Biochim Biophys Acta. 1976 Apr 14;427(2):652-62. doi: 10.1016/0005-2795(76)90209-9.
Magnetic circular dichroism (MCD) spectra were observed for native (Fe(III)) horseradish peroxidase (peroxidase, EC 1.11.1.7), its alkaline form and fluoro- and cyano-derivatives, and also for reduced (Fe(II)) horseradish peroxidase and its carbonmonoxy-- and cyano- derivatives. MCD spectra were obtained for the cyano derivative of Fe(III) horseradish peroxidase, and reduced horseradish peroxidase and its carbonmonoxy- derivative nearly identical with those for the respective myoglobin derivatives. The alkaline form of horseradish peroxidase exhibits a completely different MCD spectrum from that of myoglobin hydroxide. Thus it shows an MCD spectrum which falls into the ferric low-spin heme grouping. Native horseradish peroxidase and its fluoro derivatives show almost identical MCD spectra with those for the respective myoglobin derivatives in the visible region, though some changes were detected in the Soret region. Therefore it is concluded that the MCD spectra on the whole are sensitive to the spin state of the heme iron rather than to the porphyrin structures. The cyanide derivative of reduced horseradish peroxidase exhibited a characteristic MCD spectrum of the low-spin ferrous derivative like oxy-myoglobin.
对天然（Fe(III)）辣根过氧化物酶（过氧化物酶，EC 1.11.1.7）、其碱性形式以及氟代和氰代衍生物进行了磁圆二色性（MCD）光谱观测，同时也对还原态（Fe(II)）辣根过氧化物酶及其一氧化碳和氰代衍生物进行了观测。获得了Fe(III)辣根过氧化物酶氰代衍生物、还原态辣根过氧化物酶及其一氧化碳衍生物的MCD光谱，它们与各自肌红蛋白衍生物的光谱几乎相同。辣根过氧化物酶的碱性形式呈现出与氢氧化肌红蛋白完全不同的MCD光谱。因此，它显示出的MCD光谱属于铁离子低自旋血红素类别。天然辣根过氧化物酶及其氟代衍生物在可见光区域与各自肌红蛋白衍生物的MCD光谱几乎相同，不过在索雷特区域检测到了一些变化。因此可以得出结论，总体而言，MCD光谱对血红素铁的自旋态比对卟啉结构更敏感。还原态辣根过氧化物酶的氰化物衍生物呈现出类似氧合肌红蛋白的低自旋亚铁衍生物的特征MCD光谱。
