Myers B D, Throneberry G O
Plant Physiol. 1966 May;41(5):787-91. doi: 10.1104/pp.41.5.787.
Gossypol was examined in relation to its effect on certain enzymes and enzyme complexes associated with the tricarboxylic acid cycle and the electron transport system. Succinic dehydrogenase and cytochrome oxidase activity from sweet potato was completely inhibited by gossypol at 7.5 x 10(-3)m and 2.0 x 10(-3)m, respectively. Succinoxidase activity of the same preparations was fully inhibited at a lower concentration, 2.5 x 10(-4)m. This concentration did not affect either succinic dehydrogenase or cytochrome oxidase, the primary and terminal enzymes of the succinoxidase complex. The nature of the intermediate step or steps inhibited at this concentration is not yet known. Gossypol was further shown to inhibit phosphorylation at concentrations having no appreciable effect on oxidation. Inhibition in general was not reduced by increased substrate concentrations in the enzyme systems examined, with the exception of cytochrome c for cytochrome oxidase. Bovine serum albumin was partially effective in reducing gossypol inhibition, provided that it was present before enzyme exposure to gossypol.
对棉酚进行了研究，以考察其对与三羧酸循环和电子传递系统相关的某些酶及酶复合物的影响。棉酚对甘薯中的琥珀酸脱氢酶和细胞色素氧化酶活性分别在7.5×10⁻³m和2.0×10⁻³m时完全抑制。相同制剂的琥珀酸氧化酶活性在较低浓度2.5×10⁻⁴m时被完全抑制。该浓度对琥珀酸脱氢酶或细胞色素氧化酶（琥珀酸氧化酶复合物的起始酶和终末酶）均无影响。在此浓度下被抑制的中间步骤的性质尚不清楚。进一步表明，棉酚在对氧化没有明显影响的浓度下能抑制磷酸化。在所研究的酶系统中，除了细胞色素c对细胞色素氧化酶的作用外，一般来说，增加底物浓度并不能减轻抑制作用。牛血清白蛋白若在酶接触棉酚之前存在，则能部分有效地减轻棉酚的抑制作用。
