Inhibition of recombinant human factor D expressed in Escherichia coli using Z-Lys-thiobenzyl and 2,4-dinitrobenzenesulfonyl-fluoresceine as substrate preincubated for 1 hr followed by substrate addition by spectrofluorimetric analysis
In Vitro Assay: Recombinant human factor D (expressed in E. coli and purified using standard methods) at 10 nM concentration is incubated with test compound at various concentrations for 1 hour at room temperature in 0.1 M Hepes buffer, pH 7.5, containing 1 mM MgCl2, 1 M NaCl and 0.05% CHAPS. A synthetic substrate Z-Lys-thiobenzyl and 2,4-dinitrobenzenesulfonyl-fluoresceine are added to final concentrations of 200 μM and 25 μM, respectively. The increase in fluorescence is recorded at excitation of 485 nm and emission at 535 nm in a microplate spectrofluorimeter. IC50 values are calculated from percentage of inhibition of complement factor D-activity as a function of test compound concentration.
Competitive inhibition of human complement factor D preincubated for 1 hr followed by addition of Z-Lys-thiobenzyl ester as substrate measured over 50 mins at 1 min interval
Binding affinity to recombinant human C-terminal 6His-tagged/biotinylated complement factor D (26 to 253 residues) expressed in Sf9 insect cells by biolayer interferometry method
Binding affinity to recombinant human C-terminal 6His-tagged/biotinylated complement factor D (26 to 253 residues) expressed in Sf9 insect cells assessed as association constant measured after 300 to 900 secs by biolayer interferometry method
Binding affinity to recombinant human C-terminal 6His-tagged/biotinylated complement factor D (26 to 253 residues) expressed in Sf9 insect cells assessed as dissociation constant measured after 300 to 1800 secs by biolayer interferometry method
Inhibition of recombinant human C-terminal 6His-tagged complement factor D (26 to 253 residues) expressed in Sf9 insect cells preincubated for 1 hr followed by addition of Z-Lys-thiobenzyl ester as substrate measured over 50 mins at 1 min interval
Inhibition of human serum factor D-mediated complement activation in rabbit erythrocytes assessed as reduction in rabbit erythrocyte hemolysis preincubated with human serum for 15 mins followed by addition of rabbit erythrocytes and Mg-EGTA measured after 30 mins
In Vitro Assay: Recombinant human factor D (expressed in E. coli and purified using standard methods) at 10 nM concentration is incubated with test compound at various concentrations for 1 hour at room temperature in 0.1 M Hepes buffer, pH 7.5, containing 1 mM MgCl2, 1 M NaCl and 0.05% CHAPS. A synthetic substrate Z-Lys-thiobenzyl and 2,4-dinitrobenzenesulfonyl-fluoresceine are added to final concentrations of 200 μM and 25 μM, respectively. The increase in fluorescence is recorded at excitation of 485 nm and emission at 535 nm in a microplate spectrofluorimeter.
In Vitro Assay: Method 1: Recombinant human factor D (expressed in E. coli and purified using standard methods) at 10 nM concentration is incubated with test compound at various concentrations for 1 hour at room temperature in 0.1 M Hepes buffer, pH 7.5, containing 1 mM MgCl2, 1 M NaCl and 0.05% CHAPS. A synthetic substrate Z-Lys-thiobenzyl and 2,4-dinitrobenzenesulfonyl-fluoresceine are added to final concentrations of 200 μM and 25 μM, respectively. The increase in fluorescence is recorded at excitation of 485 nm and emission at 535 nm in a microplate spectrofluorimeter. IC50 values are calculated from percentage of inhibition of complement factor D-activity as a function of test compound concentration.
ELISA Assay: CVF-Bb complex prepared from purified cobra venom factor (1 μM), recombinant human complement factor B (expressed in drosophila cells and purified using standard methods) and human complement factor D (expressed in E. Coli, refolded and purified using standard methods). CVF-Bb complex at 3 nM concentration was incubated with test compound at various concentrations for 1 hour at room temperature in PBS pH 7.4 containing 10 mM MgCl2 and 0.05% (w/v) CHAPS. Human complement C3 substrate purified from plasma was added to a final concentration of 1 μM. After 1 hour incubation at room temperature, the enzyme reaction was stopped by addition of a cocktail of concentrated pan-protease inhibitors. The product of the reaction, C3a, was quantified by means of an enzyme-linked-immunosorbent assay.
Human Complement Factor D Assay: Method 1: Recombinant human factor D (expressed in E. coli and purified using standard methods) at 10 nM concentration is incubated with test compound at various concentrations for 1 hour at room temperature in 0.1 M Hepes buffer, pH 7.5, containing 1 mM MgCl2, 1 M NaCl and 0.05% CHAPS. A synthetic substrate Z-Lys-thiobenzyl and 2,4-dinitrobenzenesulfonyl-fluoresceine are added to final concentrations of 200 μM and 25 μM, respectively. The increase in fluorescence is recorded at excitation of 485 nm and emission at 535 nm in a microplate spectrofluorimeter.
Inhibition of recombinant human complement factor D catalytic domain (G24 to A253 residues) expressed in Escherichia coli Rosetta using Z-Lys-thiobenzyl as substrate pretreated for 1 hr followed by substrate addition by 2,4-dinitrobenzenesulfonyl-2,7-desmethyl-fluorescein probe based spectrofluorimetric thioesterolysis assay
Displacement of [19F]-Methyl (S)-2-((2-((3-(Trifluoromethoxy)phenyl)carbamoyl)-pyrrolidine-1-carboxamido)methyl)benzoate from recombinant human complement factor D catalytic domain (G24 to A253 residues) expressed in Escherichia coli Rosetta by 2D 1H 15N HSQC NMR spectroscopic analysis
Displacement of [19F]-Methyl (S)-2-((2-((3-(Trifluoromethoxy)phenyl)carbamoyl)-pyrrolidine-1-carboxamido)methyl)benzoate from recombinant human complement factor D catalytic domain (G24 to A253 residues) expressed in Escherichia coli Rosetta by 19F NMR spectroscopic analysis
Inhibition of recombinant human complement factor D catalytic domain using Z-Lys-thiobenzylester as substrate preincubated for 1 hr followed by substrate addition by 2,4-dinitrobenzenesulfonyl-2,7-desmethyl-fluorecein probe based spectrofluorimetric assay
Inhibition of recombinant human complement factor D catalytic domain (G24 to A253 residues) expressed in expressed in Escherichia coli(Rosetta) using cobra venom factor-factor B complex as substrate preincubated for 1 hr followed by substrate addition measured after 1 hr by ELISA
Inhibition of complement factor D in human whole blood assessed as decrease in zymosan-induced AP activation mediated soluble MAC complex formation preincubated for 15 mins followed by zymosan addition measured after 40 mins by ELISA