METHODS: Protein G-Sepharose sorbent was used to resolve IgG from blood of healthy donors and HIV-infected patients by affinity chromatography. Subfractions of κκ-IgG, λλ-IgG, and κλ-IgG were separated from IgGs samples of each group by affinity chromatography on sorbents containing immobilized antibodies to κ or λ light human chains. The IgG catalase activity level was measured spectrophotometrically by evaluating the decrease in optical density (A240) due to hydrogen peroxide decomposition.
RESULTS: The relative catalase activity of antibodies from HIV-infected patients (kcat = (1.41 ± 0.92) × 103 min-1, 95% CI: [1.01-1.81]) was statistically significant, 1.6 times higher (p = 0.014) compared to apparently healthy donors ((0.86 ± 0.49) × 103, 95% CI: [0.69-1.03]). The activity level of κκ-IgG HIV-infected patients ((0.44 ± 0.04) × 103 min-1) was 1.4 times higher than that of λλ-IgGs ((0.31 ± 0.025) × 103 min-1); the opposite was observed for κκ-IgGs from apparently healthy donors, which activity ((0.17 ± 0.015) × 103 min-1) was 3.1 times lower compared to λλ-IgGs ((0.53 ± 0.045) × 103 min-1).
CONCLUSIONS: Thus, the data obtained may indicate that IgG with increased catalase activity may prevent harmful processes arising from oxidative stress in HIV-infected patients, acting as an additional natural molecular mechanism of regulation of hydrogen peroxide level.
方法:蛋白G-Sepharose吸附剂用于通过亲和层析从健康供体和HIV感染患者的血液中分离IgG。κκ-IgG亚组分,λλ-IgG,通过在含有固定的κ或λ轻链抗体的吸附剂上进行亲和层析,从每组的IgG样品中分离出κλ-IgG。通过评估由于过氧化氢分解导致的光密度(A240)的降低,用分光光度法测量IgG过氧化氢酶活性水平。
结果:HIV感染患者抗体的相对过氧化氢酶活性(kcat=(1.41±0.92)×103min-1,95%CI:[1.01-1.81])具有统计学意义,与明显健康的供体((0.86±0.49)×103,95%CI:[0.69-1.03])相比,高出1.6倍(p=0.014)。HIV感染患者的κκκ-IgG活性水平((0.44±0.04)×103min-1)是λλ-IgG的1.4倍((0.31±0.025)×103min-1);对于明显健康的供体,观察到相反的情况。与λλ-IgG((0.53±0.045)×103min-1)相比,其活性((0.17±0.015)×103min-1)低3.1倍。
结论:因此,获得的数据可能表明,过氧化氢酶活性增加的IgG可以预防HIV感染患者氧化应激引起的有害过程,作为调节过氧化氢水平的附加天然分子机制。