Razygraev A V
Biomed Khim. 2012 Sep-Oct;58(5):592-8. doi: 10.18097/pbmc20125805592.
The activity utilizing the free SH-form of homocysteine with H2O2 has been found in rat blood plasma and erythrocyte lysates with the use of the glutathione peroxidase assay with hydrogen peroxide and 5,5'-dithiobis-(2-nitrobenzoic acid) and with the substitution of glutathione by homocysteine. The presence of rat plasma or erythrocyte lysate in a reaction mixture containing D,L-homocysteine, and H2O2 resulted in a marked acceleration of homocysteine concentration decrease (the decrease of homocysteine concentration was initiated by addition of hydrogen peroxide). The data obtained suggest the presence of homocysteine peroxidase activity in plasma and erythrocytes. The observed activity may be attributed to some known thiol-dependent enzymes. In the rat brain tissue, the level of the activity is extremely low (at the detection limit). The increase of the activity in blood components during post-embryonic ontogeny has also been shown. Probably, this activity contributes to low concentrations of life SH-form of homocysteine in the blood components.
利用谷胱甘肽过氧化物酶检测法，用过氧化氢和5,5'-二硫代双（2-硝基苯甲酸），并将谷胱甘肽替换为同型半胱氨酸，在大鼠血浆和红细胞裂解物中发现了利用同型半胱氨酸的游离巯基形式与过氧化氢的活性。在含有D,L-同型半胱氨酸和过氧化氢的反应混合物中加入大鼠血浆或红细胞裂解物，会导致同型半胱氨酸浓度显著加速下降（同型半胱氨酸浓度的下降是由加入过氧化氢引发的）。所得数据表明血浆和红细胞中存在同型半胱氨酸过氧化物酶活性。观察到的活性可能归因于一些已知的硫醇依赖性酶。在大鼠脑组织中，该活性水平极低（处于检测限）。还显示了胚胎后个体发育过程中血液成分中活性的增加。可能，这种活性有助于血液成分中同型半胱氨酸的低浓度活性巯基形式。
