Responses of glutathione S-transferase Acidovorax sp. KKS102 towards
antibiotics and its binding profile
Abstract
Beta class glutathione S-transferase (GST) activity is known to be
associated with antibiotic resistance, one of the most serious threats
to global health. In this research, the study of antibiotic resistance
developed by beta class GST was conducted using KKSG6, one of the GST
isozymes found in Acidovorax sp. KKS102. The KKSG6 gene has been
successfully expressed in Escherichia coli BL21 Star™ (DE3) using
pET101/D-TOPO®-KKSG6 as an expression vector, resulting in the presence
of a protein band of approximatly 20 kDa after purification using
GSTrap™ HP column. Over-expression of KKSG6 made Escherichia coli BL21
Star™ (DE3) to be less susceptible towards kanamycin, streptomycin,
gentamycin, tetracycline and chloramphenicol, suggesting the antibiotics
binding with KKSG6. Our study has revealed the KKSG6 conjugation
activity towards chloramphenicol, but not with kanamycin and
tetracycline. The inhibition of protein conjugation activity towards
CDNB by the presence of chloramphenicol has also been demonstrated. An
in-silico study using protein-ligand docking predicted that antibiotics
binding could take place at the protein dimer interface and H-site
depending on their properties.