1.Mass Spectrometric Analysis of S-Palmitoylation of Hemagglutinin from Influenza A Virus
Zujuan WANG ; Xuang GAO ; Jungbo YANG ; Wanchun SUN ; Donglun WU ; Qusheng PENG ; Nung LIU
Chinese Journal of Analytical Chemistry 2016;44(10):1521-1527
S-Palmutoylatuon un proteun us one of the most umportant kunds of lupud modufucatuon and plays a vutal role un cell sugnal transductuon, metabolusm and other processes, whuch us formed by covalent bundung of palmutuc acud wuth the sulfhydryl group of cysteune resudue un proteun through thuoester bond. In the present study, acyl-buotun exchange reactuon was performed to convert S-palmutuc acud on the hemagglutunun proteun from unfluenza A vurus unto buotun-labeled tag. The buotun-labeled proteun was then enruched by streptavudun beads and further purufued by electrophoresus, followed by un-gel dugestuon. The results showed that the ratuo of buotun concentratuon of the sample wuth hydroxylamune treatment (+HA ) to that of the sample wuthout hydroxylamune treatment (-HA) was larger than 3. Mass spectrometruc analysus of the dugestuon muxture of the enruched hemagglutunun proteun from unfluenza A vurus udentufued two s-palmutoylatuon modufucatuon sutes that were located on carboxyl termunal reguon of hemagglutunun proteun such as Cys562 and Cys565 , respectuvely. Thus research offers a specufuc and effectuve method for large-scale analysus of S-palmutoylated proteuns.
2.Enhanced autophagy protects hepatic cells from radiation injury
Lang LIU ; Dengqun LIU ; Yu WANG ; Ziwen WANG ; Zelin CHEN ; Jie CHEN ; Xiao HAN ; Zujuan LIU ; Aihua ZHANG ; Chunmeng SHI
Chinese Journal of Radiological Medicine and Protection 2018;38(5):335-343
Objective To study the influence of radiation on autophagy and its protective effect on radiation injury of hepatic cells.Methods Autophagy in mouse liver tissues was examined by GFP-LC3 staining and Western blot.Radiation-induced hepatic injury was evaluated by ALT and AST in mouse serum,protein expressions,and H & E and TUNEL staining of liver tissue.L02 cells were used for in vitro study.Chloroquine and rapamycin were used to manipulate the level of autophagy.Results Total body irradiation (TBI) of 8 Gy caused an increase of autophagy in mouse liver tissue and AST level in serum (t =-7.47,P <0.05) at 12 h after irradiation.Irradiation significantly increased the apoptotic level in liver tissue as well.Inhibition of autophagy by chloroquine caused a further increases of AST [IR:(345.42±35.25)U/L vs.IR +CQ:(433.42 ±40.07)U/L,t =-2.86,P<0.05] and ALT [IR:(35.67 ± 8.08) U/L vs.IR+CQ:(98.5±26.67)U/L,t=-3.09,P<0.05] in the serum,and it also promoted apoptosis in live tissue.However,rapamycin as an autophagy promoter showed protective effect for radiation-induced hepatic injury [AST:IR:(345.42 ± 35.25) U/L vs.IR + Rap:(278.42 ± 20.09)U/L,t =-2.86,P < 0.05].Similar changes of autophagy and apoptosis in L02 cells were also observed in the cells treated with chloroquine and rapamycin.Inhibition of autophagy by CQ caused an increase of ROS in vitro and in vivo and further increased ALT and AST levels in serum,reduced L02 cell viability.Activation of autophagy by Rap effectively reversed those changes.Conclusions Autophagy protects hepatic cells from radiation injury by decreasing ROS induction,which provides a potential target for the development of new clinical regimens against radiation induced liver injury.