On the haematin compound of peroxidase
On the haematin compound of peroxidase
复制标题
DOI：
10.1098/rspb.1937.0015
复制
发表时间：
1937-04-01
期刊：
影响因子：
--
通讯作者：
Mann, T
中科院分区：
文献类型：
--
作者：
Keilin, D;Mann, T
以辣根为原料，采用埃利奥特S法制备过氧化物酶：测定制剂中总血红素含量。作为吡啶血色素原。用Hartridge反转光谱仪确定了吸收带的位置。过氧化物酶-血红素具有亚甲基珠蛋白类型的4条带，第一条带在645米[亩]处，显示三价铁。在加入碱的情况下，形成类似碱性高铁血红蛋白的可逆化合物。Na2S2O4可逆地降低了血红素。氧化后的血红素与KCN、NO和H_2S可逆结合，形成具有特征双带光谱的化合物。NaF处理导致化合物具有4带光谱，第一带在615米[亩]比过氧化物酶的第一带645米[亩]更强。在用CO处理N2S2O4还原的过氧化物酶溶液时，出现了类似于CO-蛋氨酸-球蛋白的双带光谱。NaN3和NH_2OH不改变过氧化物酶的光谱，但改变了血红素的性质。H_2O_2的加入导致2种化合物的形成：一种是当过氧化氢按1个分子与1个铁原子的比例加入时形成的，其吸收带位于561m和530.5 m[u]；另一个是当过氧化氢大量存在时形成的2d，其吸收带位于583和545.5 m[u]。这两种化合物在受体的存在下都是不稳定的。在过氧化氢-过氧化物酶化合物中，铁是三价的，因为它们不会与CO结合，在对苯二酚存在下分解，释放出过氧化物酶，在645m[Mu]处有一个吸收带。在过氧化氢存在下，NaN3与过氧化物酶结合，形成具有两个吸收带的化合物，CO不与之反应。羟胺化合物的唯一证据是胺能抑制过氧化氢-过氧化物酶的形成。酶活性与浓度之间存在严格的比例关系。从645米处的吸收带的强度估计的血红素化合物，而不是活性和总的血红素之间；过氧化物酶，血红素并不是唯一存在的。过氧化物酶类似高铁血红蛋白，因此可以被认为是原血红素和天然蛋白的化合物。在高铁血红蛋白和过氧化氢酶中发现了相同的血红素核。
The peroxidase was prepared from horseradish roots by Elliott''s method: total hematin of the preparation was detd. as pyridine hemo-chromogen. The Hartridge reversion spectroscope was used to determine the position of the absorption bands. Peroxidase hematin has a 4-banded spectrum of the methembglobin type, with the first band at 645 m[mu] showing trivalent iron. On adding alkali, a reversible compound resembling alkaline methemoglobin is formed. Na2S2O4 reversibly reduces the hematin. The oxidized hematin reversibly combines with KCN, NO and H2S to form compounds with characteristic 2-banded spectra. NaF treatment results in a compound with 4-banded spectrum with the first band at 615 m[mu] more intense than the first 645 m[mu] band of the peroxidase. On treatment of the N2S2O4-reduced peroxidase solution with CO a 2-banded spectrum resembling that of CO-methem-oglobin appears. NaN3 and NH2OH do not modify the peroxidase spectrum, but do change the properties of the hematin. H2O2 addition results in the formation of 2 compounds: one formed when the peroxide is added in the proportion of 1 molecule to 1 atom Fe, with absorption bands at 561 and 530.5 m[mu]; a 2d when the peroxide is present in great excess, with bands at 583 and 545.5 m[mu]. Both these compounds are unstable in the presence of acceptors undergoing peroxidatic oxidation. The iron is trivalent in the H2O2-peroxidase compounds, since they will not combine with CO, and in the presence of hydroquinone are decomposed, liberating the peroxidase with an absorption band at 645 m[mu]. NaN3 combines with peroxidase in the presence of peroxide, forming a compound with 2 absorption bands, with which CO does not react. The only evidence for a hydroxyl-amine compound is that the amine inhibits the formation of H2O2-peroxidase. There is strict proportionality between enzyme activity and the concn. of the hematin compound estimated from the intensity of the absorption band at 645 m[mu], but not between activity and total hematin; the peroxidase hematin is not the only hematin present. Peroxidase resembles methemoglobin, and so can be considered as a compound of protohematin and native protein. The same hematin nucleus is found in methemoglobin and catalase.