A novel capillary electrophoresis method coupled with on-line microdialysis using an attachable electrode has been developed to study the interaction of macromolecule with small molecule. The binding constants of bovi...A novel capillary electrophoresis method coupled with on-line microdialysis using an attachable electrode has been developed to study the interaction of macromolecule with small molecule. The binding constants of bovine serum album (BSA) with D,L-tryptophan (Trp), sulfamethoxazole (SMZ) with trypsin and chymotrypsin were determined. These values are 2.3 x 10(4)L/mol for BSA-L-Trp; 1.77 x 10(3) L/mol for BSA-D-Trp in pH 7.4, 50 mmol/ L phosphate; 1.4 x 10(4) L/mol for SMZ- trypsin and 6.0 x 10(3) L/mol for SMZ-chymotrypsin in pH 6.5, 25 mmol/L Tris buffer. The proposed method has merits of speed, low sample consumption and readily available to be performed in desired physiological conditions.展开更多
By introducing cell membrane into electrophoretic buffer as pseudo-stationary phase,a novel capillary electrophoresis method was established to explore the interaction between drugs and cell membrane,where the interac...By introducing cell membrane into electrophoretic buffer as pseudo-stationary phase,a novel capillary electrophoresis method was established to explore the interaction between drugs and cell membrane,where the interaction between citalopram and rabbit red blood cell membrane was used as an example. A series of concentrations of cell membrane were suspended into the running buffer by peak-shift method. The binding constant of citalopram to rabbit red blood cell membrane of 0.977 g-1·L was obtained after treatment of Scatchard plot. This method could provide not only a new way for the investigation on the interactions between drugs and cell membrane,but also a new approach for high throughput screening of the drug membrane permeability,biological activity,and evaluating drugs in vivo.展开更多
Based on the chiral separation of several basic drugs, dimetindene, tetryzoline, theodrenaline and verapamil, the liquid pre-column capillary electrophoresis (LPC-CE) technique was established. It was used to determin...Based on the chiral separation of several basic drugs, dimetindene, tetryzoline, theodrenaline and verapamil, the liquid pre-column capillary electrophoresis (LPC-CE) technique was established. It was used to determine free concentrations of dmg enantiomers in mixed solutions with human serum albumin (HSA). To prevent HSA entering the CE chiral srparation zone, the mobility differences between HSA and drugs under a specific pH condition were employed in thr LPC. Thus, the detection confusion caused by protein was totally avoided. Further study of binding constants determination and protein binding competitions was carried out. The study proves that the LPC technique could be used for complex mrdia, particularly the matrix of protein coexisting with a variety of dmgs.展开更多
The binding constant( K b) between fluorescein isothiocyanate labeled bovine serum albumin(FITC BSA) and its monoclonal antibody was determined using the ligand separation mode of affinity capillary electrophoresis(AC...The binding constant( K b) between fluorescein isothiocyanate labeled bovine serum albumin(FITC BSA) and its monoclonal antibody was determined using the ligand separation mode of affinity capillary electrophoresis(ACE) with laser induced fluorescence detection(LIF). Free FITC BSA and the complexes were separated by capillary electrophoresis in 7 min after incubation. The running buffer was 100 mmol/L HEPES at pH 7 4, and separation voltage was 30 kV. The K b was determined to be 4 7×10 8 L/mol using Scatchard plotting method. The influences of incubation time and electrophoresis conditions on determination were also studied.展开更多
文摘A novel capillary electrophoresis method coupled with on-line microdialysis using an attachable electrode has been developed to study the interaction of macromolecule with small molecule. The binding constants of bovine serum album (BSA) with D,L-tryptophan (Trp), sulfamethoxazole (SMZ) with trypsin and chymotrypsin were determined. These values are 2.3 x 10(4)L/mol for BSA-L-Trp; 1.77 x 10(3) L/mol for BSA-D-Trp in pH 7.4, 50 mmol/ L phosphate; 1.4 x 10(4) L/mol for SMZ- trypsin and 6.0 x 10(3) L/mol for SMZ-chymotrypsin in pH 6.5, 25 mmol/L Tris buffer. The proposed method has merits of speed, low sample consumption and readily available to be performed in desired physiological conditions.
基金Supported by the National Natural Science Foundation of China (Grant No. 20775096)the Natural Science Foundation of Chongqing (Grant No. 2006BB5177)
文摘By introducing cell membrane into electrophoretic buffer as pseudo-stationary phase,a novel capillary electrophoresis method was established to explore the interaction between drugs and cell membrane,where the interaction between citalopram and rabbit red blood cell membrane was used as an example. A series of concentrations of cell membrane were suspended into the running buffer by peak-shift method. The binding constant of citalopram to rabbit red blood cell membrane of 0.977 g-1·L was obtained after treatment of Scatchard plot. This method could provide not only a new way for the investigation on the interactions between drugs and cell membrane,but also a new approach for high throughput screening of the drug membrane permeability,biological activity,and evaluating drugs in vivo.
文摘Based on the chiral separation of several basic drugs, dimetindene, tetryzoline, theodrenaline and verapamil, the liquid pre-column capillary electrophoresis (LPC-CE) technique was established. It was used to determine free concentrations of dmg enantiomers in mixed solutions with human serum albumin (HSA). To prevent HSA entering the CE chiral srparation zone, the mobility differences between HSA and drugs under a specific pH condition were employed in thr LPC. Thus, the detection confusion caused by protein was totally avoided. Further study of binding constants determination and protein binding competitions was carried out. The study proves that the LPC technique could be used for complex mrdia, particularly the matrix of protein coexisting with a variety of dmgs.
文摘The binding constant( K b) between fluorescein isothiocyanate labeled bovine serum albumin(FITC BSA) and its monoclonal antibody was determined using the ligand separation mode of affinity capillary electrophoresis(ACE) with laser induced fluorescence detection(LIF). Free FITC BSA and the complexes were separated by capillary electrophoresis in 7 min after incubation. The running buffer was 100 mmol/L HEPES at pH 7 4, and separation voltage was 30 kV. The K b was determined to be 4 7×10 8 L/mol using Scatchard plotting method. The influences of incubation time and electrophoresis conditions on determination were also studied.
