Attwood D, Graham A B, Wood G C
Biochem J. 1971 Aug;123(5):875-82. doi: 10.1042/bj1230875.
Specific degradation of the phospholipid membrane of guinea-pig liver microsomal fraction with phospholipase A inactivated glucuronyltransferase. The inactivation was reversed by phosphatidylcholine and mixed microsomal phospholipid micelles at concentrations similar to those present in intact microsomal preparations. The other commonly occurring phospholipids did not reactivate phospholipase A-treated enzyme. Since the mixed microsomal phospholipids consisted mainly of phosphatidylcholine, it is concluded that the reactivation by phospholipids is phosphatidylcholine-specific. Reactivation was also achieved by low concentrations of the cationic detergents cetylpyridinium chloride and cetyltrimethylammonium bromide. Higher concentrations of these detergents inactivated the glucuronyltransferase activity of intact and phospholipase A-treated microsomal fractions. Anionic detergents were potent inactivators of the glucuronyltransferase activity of untreated and phospholipase A-treated microsomal fractions, whereas non-ionic detergents had little effect on the activity of either preparation. Measurements of the zeta-potentials of the micellar species used in this study showed that no obvious relationship existed between the zeta-potentials and the ability to reactivate glucuronyltransferase. However, high positive or negative zeta-potentials were correlated with the ability of the amphipathic compound to inactivate glucuronyltransferase.
用磷脂酶A特异性降解豚鼠肝微粒体部分的磷脂膜会使葡糖醛酸基转移酶失活。磷脂酰胆碱和混合微粒体磷脂胶束在与完整微粒体制剂中相似的浓度下可逆转这种失活。其他常见的磷脂不能使经磷脂酶A处理的酶重新激活。由于混合微粒体磷脂主要由磷脂酰胆碱组成，因此得出结论，磷脂的重新激活具有磷脂酰胆碱特异性。低浓度的阳离子去污剂十六烷基吡啶氯化物和十六烷基三甲基溴化铵也能实现重新激活。这些去污剂的较高浓度会使完整的和经磷脂酶A处理的微粒体部分中的葡糖醛酸基转移酶活性失活。阴离子去污剂是未处理的和经磷脂酶A处理的微粒体部分中葡糖醛酸基转移酶活性的有效失活剂，而非离子去污剂对两种制剂的活性影响很小。对本研究中使用的胶束物种的ζ电位测量表明，ζ电位与重新激活葡糖醛酸基转移酶的能力之间不存在明显关系。然而，高正或负ζ电位与两亲化合物使葡糖醛酸基转移酶失活的能力相关。
