p47phox蛋白第73位脯氨酸在中性粒细胞NADPH氧化酶激活中的新作用。

A new role of Pro-73 of p47phox in the activation of neutrophil NADPH oxidase.

作者信息

Nagasawa Teruaki, Ebisu Kentaro, Inoue Yasuyuki, Miyano Kei, Tamura Minoru

机构信息

Department of Applied Chemistry, Faculty of Engineering, Ehime University, Matsuyama, 790-8577, Ehime, Japan.

出版信息

Arch Biochem Biophys. 2003 Aug 1;416(1):92-100. doi: 10.1016/s0003-9861(03)00296-0.

DOI:10.1016/s0003-9861(03)00296-0

PMID:12859985

Abstract

The PX domain of p47phox is thought to be involved in autoinhibition. However, when the domain was deleted, the ability to activate the phagocyte NADPH oxidase was markedly diminished. We have mutated the proline-rich region of the PX domain and examined the mutants for the ability to activate. Substitution of Gln for Pro-73 of p47phox(1-286) (P73Q) resulted in a considerably lower activity than the wild type and P73Q had a much lower affinity for the oxidase complex. Whereas, Gln substitution for Pro-76 (P76Q) showed a slightly enhanced activation and the mutant had a slightly higher affinity for the complex than the wild type. Affinity for p67phox(1-210) was slightly decreased either by P73Q or P76Q. Optimal SDS concentration for the activation was lowered by these mutations. Binding of PX domain with phosphatidylinositol-3,4-bisphosphate was diminished by P73Q mutation. The results in this study suggest that Pro-73 has a role in interaction with the catalytic component cytochrome b558.

摘要

p47phox的PX结构域被认为与自身抑制有关。然而，当该结构域被删除时，激活吞噬细胞NADPH氧化酶的能力显著降低。我们对PX结构域富含脯氨酸的区域进行了突变，并检测了这些突变体的激活能力。将p47phox(1-286)的Pro-73替换为Gln（P73Q）导致活性比野生型显著降低，并且P73Q对氧化酶复合物的亲和力低得多。而将Pro-76替换为Gln（P76Q）显示激活略有增强，并且该突变体对复合物的亲和力比野生型略高。P73Q或P76Q对p67phox(1-210)的亲和力略有降低。这些突变降低了激活所需的最佳SDS浓度。P73Q突变减少了PX结构域与磷脂酰肌醇-3,4-二磷酸的结合。本研究结果表明，Pro-73在与催化成分细胞色素b558的相互作用中起作用。