title: Construction of Trichosanthin Mutant R122G and Its Activity Study.
abstract: AGG, the codon of 122 Arg of trichosanthin (TCS) was mutated to GGG (Gly) by U-DNA site-directed mutagenesis. The mutant TCS was expressed and purified from the supernatant of host cells, its activities were assayed and compared with expressed wild-type TCS. The results showed that the R122G TCS was still active as a RNA N-glycosidase but its ability to inhibit protein synthesis was 160-fold less than that of wild-type TCS, its abortifacient ability on mid-term gestated mice reduced from 100% to 9.3%, which suggested that 122 Arg was indirectly involved in the catalysis, and it played an important role in its bioactivities.
authors.affiliation: Shanghai Institute of Cell Biology, the Chinese Academy of Sciences, Shanghai 200031, China. knyhbl@sunm.shcnc.ac.cn
authors.forename: Hui-Dong
authors.initials: HD
authors.lastname: Yuan
authors.forename: Xin-Yong
authors.initials: XY
authors.lastname: Ke
authors.forename: Yi-Bao
authors.initials: YB
authors.lastname: Ke
authors.forename: Mei
authors.initials: M
authors.lastname: Kong
authors.forename: Xin-Yong
authors.initials: XY
authors.lastname: Ke
authors.forename: Qi-Chang
authors.initials: QC
authors.lastname: Xia
authors.forename: Zu-Chuan
authors.initials: ZC
authors.lastname: Zhang
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Nie