Kohen R, Misgav R, Ginsburg I
Department of Pharmacy, Hebrew University of Jerusalem, Hadasaah Medical Center, Israel.
Free Radic Res Commun. 1991;12-13 Pt 1:179-85. doi: 10.3109/10715769109145784.
Carnosine, anserine and homocarnosine are natural compounds which are present in high concentrations (2-20 mM) in skeletal muscles and brain of many vertebrates. We have demonstrated in a previous work that these compounds can act as antioxidants, a result of their ability to scavenge peroxyl radicals, singlet oxygen and hydroxyl radicals. Carnosine and its analogues have been shown to be efficient chelating agents for copper and other transition metals. Since human skeletal muscle contains one-third of the total copper in the body (20-47 mmol/kg) and the concentration of carnosine in this tissue is relatively high, the complex of carnosine:copper may be of biological importance. We have studied the ability of the copper:carnosine (and other carnosine derivatives) complexes to act as superoxide dismutase. The results indicate that the complex of copper:carnosine can dismute superoxide radicals released by neutrophils treated with PMA in an analogous mechanism to other amino acids and copper complexes. Copper:anserine failed to dismute superoxide radicals and copper:homocarnosine complex was efficient when the cells were treated with PMA or with histone-opsonized streptococci and cytochalasine B. The possible role of these compounds to act as physiological antioxidants that possess superoxide dismutase activity is discussed.
肌肽、鹅肌肽和高肌肽是天然化合物，在许多脊椎动物的骨骼肌和大脑中大量存在（浓度为2 - 20 mM）。我们在之前的一项研究中表明，这些化合物能够作为抗氧化剂，这是由于它们具有清除过氧自由基、单线态氧和羟基自由基的能力。肌肽及其类似物已被证明是铜和其他过渡金属的有效螯合剂。由于人体骨骼肌中含有体内总铜量的三分之一（20 - 47 mmol/kg），且该组织中肌肽的浓度相对较高，肌肽与铜的复合物可能具有生物学重要性。我们研究了铜与肌肽（以及其他肌肽衍生物）的复合物作为超氧化物歧化酶的能力。结果表明，铜与肌肽的复合物能够以与其他氨基酸和铜复合物类似的机制使经佛波酯处理的中性粒细胞释放的超氧自由基发生歧化反应。当细胞用佛波酯或经组蛋白调理的链球菌和细胞松弛素B处理时，铜与鹅肌肽不能使超氧自由基发生歧化反应，而铜与高肌肽的复合物则有效。本文讨论了这些化合物作为具有超氧化物歧化酶活性的生理抗氧化剂的可能作用。
