哺乳动物紫色酸性磷酸酶的磷酸酶活性和氧自由基生成活性在功能上是独立的。

Phosphatase and oxygen radical-generating activities of mammalian purple acid phosphatase are functionally independent.

作者信息

Kaija Helena, Alatalo Sari L, Halleen Jussi M, Lindqvist Ylva, Schneider Gunter, Väänänen H Kalervo, Vihko Pirkko

机构信息

Biocenter Oulu, Research Center for Molecular Endocrinology, Oulu University Hospital, University of Oulu, FIN-90014 Finland.

出版信息

Biochem Biophys Res Commun. 2002 Mar 22;292(1):128-32. doi: 10.1006/bbrc.2002.6615.

DOI:10.1006/bbrc.2002.6615

PMID:11890682

Abstract

Bone-resorbing osteoclasts and activated macrophages express large amounts of tartrate-resistant acid phosphatase (TRAP), an iron-containing enzyme with unknown biological function. We studied acid phosphatase (AcP) and reactive oxygen species (ROS)-generating activities of recombinant rat TRAP. pH optimum was 4.5 for AcP activity and 6.5 for ROS-generating activity. Replacement of His113 and His216 by site-directed mutagenesis severely inhibited AcP activity, but had no significant effects on ROS-generating activity. Substrate specificity was not affected by the mutations. These results suggest that AcP and ROS-generating activities of TRAP are functionally independent.

摘要

骨吸收破骨细胞和活化巨噬细胞表达大量抗酒石酸酸性磷酸酶（TRAP），这是一种含铁酶，其生物学功能未知。我们研究了重组大鼠TRAP的酸性磷酸酶（AcP）和活性氧（ROS）生成活性。AcP活性的最适pH为4.5，ROS生成活性的最适pH为6.5。通过定点诱变将His113和His216替换后，AcP活性受到严重抑制，但对ROS生成活性没有显著影响。突变不影响底物特异性。这些结果表明，TRAP的AcP和ROS生成活性在功能上是独立的。