Download MendeleyStructural and functional analysis of the inhibition of equine glutathione transferase A3-3 by organotin endocrine disrupting pollutants.
Skerlova, J., Ismail, A., Lindstrom, H., Sjodin, B., Mannervik, B., Stenmark, P.(2021) Environ Pollut 268: 115960-115960
- PubMed: 33162212
- DOI: https://doi.org/10.1016/j.envpol.2020.115960
- Primary Citation of Related Structures:
6ZJ9, 6ZJC - PubMed Abstract:
Organotin compounds are highly toxic environmental pollutants with neurotoxic and endocrine-disrupting effects. They are potent inhibitors of glutathione transferases (GSTs), thus impeding their detoxication and antioxidant functions. Several GSTs, including equine GST A3-3 (EcaGST A3-3), exhibit steroid double-bond isomerase activity and are involved in the biosynthesis of testosterone and progesterone. We have performed enzyme kinetics analyses of the inhibition of EcaGST A3-3 by organotin compounds. We have also solved crystal structures of EcaGST A3-3 in complexes with glutathione, and with glutathione together with covalently bound triethyltin. Our structural data indicate that the tin atom forms strong bonds with a covalent character not only with the glutathione, but also with a tyrosyl residue of the enzyme itself, thereby preventing the release of the glutathione-organotin adduct and completely blocking the enzyme function. This work presents a structural basis for the general mechanism of GST inhibition by organotin compounds and contributes to the understanding of their neurotoxic and endocrine disrupting effects.
Organizational Affiliation:
Department of Biochemistry and Biophysics, Stockholm University, SE-10691, Stockholm, Sweden.
