Exploring O-acetylserine sulfhydrylase-B isoenzyme from Salmonella typhimurium by fluorescence spectroscopy

► Comparison of spectroscopic properties of wild type OASS-B and OASS-A. ► Differences in protein dynamics affect the formation of the α-aminoacrylate. ► Spectroscopic investigation of OASS-B Trp mutants. ► Trp28 in OASS-B is mainly responsible for direct Trp fluorescence emission. ► Trp212 mainly involved in energy-transfer to the PLP cofactor and its mutation affects OASS-B function.