Gijsbers Rik, Aoki Junken, Arai Hiroyuki, Bollen Mathieu
Afdeling Biochemie, Faculteit Geneeskunde, University of Leuven, Herestraat 49, B-3000 Leuven, Belgium.
FEBS Lett. 2003 Mar 13;538(1-3):60-4. doi: 10.1016/s0014-5793(03)00133-9.
Autotaxin (NPP2) is a tumor cell motility-stimulating factor that displays both a nucleotide pyrophosphatase/phosphodiesterase activity and a recently described lysophospholipase D activity. The hydrolysis of nucleotides is a metal-assisted reaction that occurs via a nucleotidylated threonine in the catalytic site. We show here that the catalytic site threonine and the metal-coordinating residues are also essential for the hydrolysis of lysophospholipids. In comparing the substrate specificity of NPP2 and the closely related NPP1 and NPP3, we found that only NPP2 displayed a lysophospholipase D activity, whereas NPP1 and NPP3 had a much higher nucleotide pyrophosphatase activity.
自分泌运动因子（NPP2）是一种肿瘤细胞运动刺激因子，它兼具核苷酸焦磷酸酶/磷酸二酯酶活性以及最近发现的溶血磷脂酶D活性。核苷酸的水解是一种金属辅助反应，通过催化位点上的核苷酸化苏氨酸发生。我们在此表明，催化位点的苏氨酸和金属配位残基对于溶血磷脂的水解也至关重要。在比较NPP2与密切相关的NPP1和NPP3的底物特异性时，我们发现只有NPP2具有溶血磷脂酶D活性，而NPP1和NPP3具有更高的核苷酸焦磷酸酶活性。
