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Updated: May 22, 2026
Spectrophotometric Screening for Potential Inhibitors of Cytosolic Glutathione S-Transferases
Published on: October 10, 2020
Structural basis for catalytic activity of a silkworm Delta-class glutathione transferase
Kohji Yamamoto1, Kazuhiro Usuda, Yoshimitsu Kakuta
1Faculty of Agriculture, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. yamamok@agr.kyushu-u.ac.jp
Background:
Glutathione transferase (GST) catalyzes glutathione conjugation, a major detoxification pathway for xenobiotics and endogenous substances. Here, we determined the crystal structure of a Delta-class GST from Bombyx mori (bmGSTD) to examine its catalytic residues.
Methods:
The three-dimensional structure of bmGSTD was resolved by the molecular replacement method and refined to a resolution of 2.0Å.
Results:
Structural alignment with a Delta-class GST of Anopheles gambiae indicated that bmGSTD contains 2 distinct domains (an N-terminal domain and a C-terminal domain) connected by a linker. The bound glutathione localized at the N-terminal domain. Putative catalytic residues were changed to alanine by site-directed mutagenesis, and the resulting mutants were characterized in terms of catalytic activity using glutathione and 1-chloro-2,4-dinitrobenzene, a synthetic substrate of GST. Kinetic analysis of bmGSTD mutants indicated that Ser11, Gln51, His52, Ser67, and Arg68 are important for enzyme function.
General Significance:
These results provide structural insights into the catalysis of glutathione conjugation in B. mori by bmGSTD.
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