| Assay Method Information | |
| | Biological Assays |
| Description: | Human PDE4A3 coding sequence (amino acids 2 to 825 from the sequence with accession number NP_001104779) was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include an N-terminal His6 affinity tag and a c-terminal FLAG affinity tag to aid in purification. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection. Insect cell paste was lysed and after centrifugation, the supernatant was batch bound to Ni-NTA agarose (GE Healthcare) and eluted with 250 mM imidazole. This eluate was diluted with FLAG buffer (50 mM Tris HCL pH 7.5, 100 mM NaCl, 5% Glycerol, 1 mM TCEP with protease inhibitors) and batch bound to ant-FLAG M2 agarose (Sigma) overnight at 4° C. The agarose was packed into a column, washed with buffer and eluted with buffer containing elute using 250 ug/ml Flag-peptide. Fractions were analyzed using SDS-PAGE Coomassie blue staining and pooled based on purity. Pooled fractions were chromatographed on a S200 120 ml column (GE Healthcare) in 50 mM Tris HCL pH 7.5, 150 mM NaCl, 10% Glycerol, 2 mM TCEP with protease inhibitors. PDE4A3 fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, dialyzed against 50 mM Tris HCL pH 7.5, 100 mM NaCl, 20% Glycerol, 2 mM TCEP, frozen and stored at −80° C.Human PDE4B1 coding sequence (amino acids 122 to 736 from the sequence with accession number Q07343) with the mutations resulting in the amino acid substitutions S134E, S654A, S659A, and S661A was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include a N-terminal His6 affinity tag to aid in purification followed by a thrombin cleavage site. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. Insect cell paste was lysed and after centrifugation, the supernatant was chromatographed on Ni-NTA agarose (Qiagen) as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. Ni-NTA agarose eluting fractions containing PDE4 were pooled, diluted with Q buffer A (20 mM Tris HCl pH 8, 5% glycerol, 1 mM TCEP) to reduce NaCl to −100 mM and loaded on a Source 15Q (GE Healthcare) column. After washing with Q buffer A/10% buffer B to baseline, PDE4D was eluted with a gradient from 10% to 60% of Buffer B (20 mM Tris HCl pH 8, 1 M NaCl, 5% glycerol, 1 mM TCEP). PDE4D fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, frozen and stored at −80° C.Human PDE4C1 coding sequence (amino acids 2 to 712 from the sequence with accession number NP_000914.2) was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include an N-terminal His6 affinity tag and a c-terminal FLAG affinity tag to aid in purification. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection. Insect cell paste was lysed and after centrifugation, the supernatant was batch bound to Ni-NTA agarose (GE Healthcare) and eluted with 250 mM imidazole. This eluate was diluted with FLAG buffer (50 mM Tris HCL pH 7.5, 100 mM NaCl, 5% Glycerol, 1 mM TCEP with protease inhibitors) and batch bound to ant-FLAG M2 agarose (Sigma) overnight at 4° C. The agarose was packed into a column, washed with buffer and eluted with buffer containing elute using 250 ug/ml Flag-peptide. Fractions were analyzed using SDS-PAGE Coomassie blue staining and pooled based on purity. |
| Affinity data for this assay | |
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