標題: A nano switch mechanism for the redox-responsive sulfotransferase
作者: Lin, Chih-Heng
Lin, En-Shyh
Su, Tian-Mu
Hung, Kuo-Sheng
Yang, Yuh-Shyong
生物科技學系
Department of Biological Science and Technology
關鍵字: Sulfotransferase;Redox regulation;Drug metabolism;Xenobiotics;Glutathione
公開日期: 15-七月-2012
摘要: Cellular redox signaling is important in diverse physiological and pathological processes. The activity of rat phenol sulfotransferase (rSULT1A1), which is important for the metabolism of hormone and drug, is subjected to redox regulation. Two cysteines, Cys232 and Cys66, nanometer away from each other and from the enzyme active site were proposed to form disulfide bond to regulate the activity of rSULT1A1. A nano switch, composed of a flexible loop from amino acid residues 59-70, explained how this long distance interaction between two cysteines can be achieved. The enzyme properties were investigated through site-directed muatagnesis, circular dichroism, enzyme kinetics and homologous modeling of the rSULT1A1 structures. We proposed that the formation of disulfide bond between Cys232 and Cys66 induced conformational changes of sulfotransferase, then in turn affected its nucleotide binding and enzyme activity. This discovery was extended to understand the possible redox regulation of other sulfotransferases from different organisms. The redox switch can be created in other redox-insensitive sulfotransferases, such as human phenol sulfotransferase (hSULT1A1) and human alcohol sulfotransferase (hSULT2A1), to produce mutant enzymes with redox regulation capacity. This study strongly suggested that redox regulation of drug and hormone metabolism can be significantly varied even though the sequence and structure of SULT1A1 of human and rat have a high degree of homology. (C) 2012 Elsevier Inc. All rights reserved.
URI: http://hdl.handle.net/11536/16246
ISSN: 0006-2952
期刊: BIOCHEMICAL PHARMACOLOGY
Volume: 84
Issue: 2
結束頁: 224
顯示於類別:期刊論文


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