6-hydroxy-4-methylbenzo[d]thiazole-2-carbonitrile

6-Hydroxy-4-Methylbenzo[d]Thiazole-2-Carbonitrile for the Functional Expression Study of Sulfotransferases

Sun, Yanan, et al. Biomolecules, 2020, 10(11), 1517.

This work evaluated fission yeast as a host for recombinant expression of human SULTs and assessed its suitability for functional production of sulfotransferases (SULTs), including SULT4A1 and SULT6B1. A series of biotransformation and substrate docking experiments were performed using UGT-Glo substrates A (GSA, 6-hydroxy-4-methylbenzo[d]thiazole-2-carbonitrile) and B (GSB, 6-((3-aminobenzyl)amino)benzo[d]thiazole-2-carbonitrile).
Experimental results related to GSA
· Sulfation reactions were carried out using the S9 fraction of human hepatocytes, along with the cofactor PAPS and GSA or GSB. The results indicated that GSA, but not GSB, was metabolized by the S9 fraction in a manner dependent on PAPS. LC-MS analysis further validated the production of sulfated GSA. This evidence suggests that GSA serves as a substrate for sulfotransferases (SULTs) present in the S9 fraction of human hepatocytes, with the sulfation of GSA primarily linked to the activity of SULT2A1.
· To explore the activity trends of GSA, homology models was developed for the catalytically active SULT4A1 and SULT6B1, incorporating the unique aspect of PAPS cofactor binding. A structural analysis of the four SULT isoforms that metabolize GSA revealed distinct shapes of their active sites. SULT1E1 and SULT2A1 feature a narrower, slot-like substrate pocket, while SULT4A1 and SULT6B1 possess a larger, more spacious active site.
· Molecular docking studies of GSA indicate that the less constricted active sites in SULT4A1 and SULT6B1 facilitate improved substrate binding, consequently enhancing the rate of sulfation.