Inhibition of curcumin derivative C1209 on proliferation of CML cells by disrupting Hsp90 chaperon function / 中国药理学通报

Aim To estimate the inhibition of curcumin derivative C1209 on the proliferation of chronic myeloid leukemia (CML) cells involving the disruption Hsp90 chaperon function. Methods The fluorescence spec-trum experiment was applied to examine the affinity be-tween different C1209 concentrations and Hsp90, NH-sp90,MHsp90,CHsp90;fluorescence intensities were recorded in the range of 290~510 nm at 293 K,303 K and 310 K,respectively;a colorimetric assay for in-organic phosphate based on the formation of a phospho-molybdate complex and subsequent reaction with mala-chite green was used to examine the inhibitory effects of C1209 on the activity of Hsp90 ATPase. MTT assay and CFSE were used for K562 and K562/G01cell pro-liferation determination in vitro by C1209. Western blot was used to detect the client proteins and the mo-lecular chaperone of Hsp90 level. Results The disso-ciation constant KDvalues of C1209 was (14.733 ± 0.713) μmol·L-1. The interaction between C1209 and Hsp90 was driven mainly by electrostatic interac-tion. C1209 showed the strongest affinity with CHsp90. When the concentration of ATP was 1mmol· L-1,the inhibition of Hsp90 ATPase activity of C1209 with the IC50value was 11.4 μmol·L-1; C1209 showed inhibition of K562 and K562/G01cells in dose-dependent proliferation and the IC50value was 1.14 μmol·L-1and 0.56 μmol·L-1, respectively after 24 h incubation. C1209 affected the molecular chaper-one functions of Hsp90 and down-regulated Bcr-Abl, Akt, MEK, ERK, c-Raf, p-Akt, p-MEK and p-ERK protein levels which were client proteins of Hsp90 in K562 and K562/G01cells. Conclusions Curcumin derivative C1209 is Hsp90 inhibitor;C1209 has signif-icant inhibitory effects on proliferation of K562 and K562 / G01, which may be related to C1209 affecting the molecular chaperone functions of Hsp90 and down-regulating client proteins of Hsp90 level.

Study on the Interaction of Gliotoxin with BSA / 微生物学通报

The interaction between Gliotoxin and bovine serum albumin (BSA) was studied by the fluo-rescence, Circular Dichroism (CD) and ultraviolet visible (UV-Vis) techniques. The fluorescent experiment showed that the intrinsic fluorescence of BSA was quenched by the binding of gliotoxin in a static quenching procedure, with an association constant of 7.2?103 L/mol and in hydropobic forces. And the CD spectrum revealed that gliotoxin effected the conformation of BSA by increased the mass of ?-helix.