Greffard A, Trabelsi N, Terzidis H, Bignon J, Jaurand M C, Pilatte Y
Inserm U139, Institut Mondor de Médecine Moléculaire (IM3), Hopital Henri Mondor, Créteil, France.
Biochim Biophys Acta. 1997 Mar 15;1334(2-3):140-8. doi: 10.1016/s0304-4165(96)00089-x.
Sulfated glycosaminoglycans are known to inhibit mammalian acid-active sialidase. Although the inhibition depends clearly on the presence of sulfate groups on these macromolecules, there was no information on the intrinsic inhibitory potency of inorganic sulfate. In this study, we demonstrate that inorganic sulfates inhibit acid-active Mu-Neu5Ac sialidase of U937 cells. This inhibition was found to be reversible and it appeared to be of the mixed competitive type. Sulfate-induced inhibition was also observed in other cells as well as with other substrates such as sialyl lactose and bovine mixed brain gangliosides. We conclude that the intrinsic inhibitory potency of sulfate groups may be significantly involved in the inhibition of acid-active sialidase by sulfated glycosaminoglycans. In addition, inorganic sulfate by its apparent potency to selectively inhibit acid sialidases might constitute an interesting tool for the characterisation of the minor forms of sialidases occurring in mammalian cells.
硫酸化糖胺聚糖已知可抑制哺乳动物的酸性唾液酸酶。尽管这种抑制显然取决于这些大分子上硫酸基团的存在，但关于无机硫酸盐的内在抑制效力却没有相关信息。在本研究中，我们证明无机硫酸盐可抑制U937细胞的酸性Mu-Neu5Ac唾液酸酶。这种抑制是可逆的，且似乎属于混合竞争型。在其他细胞中以及使用其他底物（如唾液酸乳糖和牛混合脑苷脂）时也观察到了硫酸盐诱导的抑制作用。我们得出结论，硫酸基团的内在抑制效力可能在硫酸化糖胺聚糖对酸性唾液酸酶的抑制中起重要作用。此外，无机硫酸盐因其明显的选择性抑制酸性唾液酸酶的能力，可能成为表征哺乳动物细胞中存在的次要唾液酸酶形式的有趣工具。
