| Assay Method Information | |
| | GSKbeta Assay |
| Description: | Types of GSK-3 assay used to test the selectivity/off target potential compounds of the invention with respect to PKC ±/ inhibition activity includes the following: Type 1: The GSK-3 specific peptide used in this assay was derived from the phosphorylation site of glycogen synthase and its sequence is: YRRAAVPPSPSLSRHSSPHQ(S)EDEEE (SEQ ID NO: 1). (S) is pre-phosphorylated as is glycogen synthase in vivo and the three consensus sites for GSK-3 specific phosphorylation are underlined. The buffer used to make up the glycogen synthase peptide and [γ-33P] ATP consisted of MOPS 25 mM, EDTA 0.2 mM, magnesium acetate 10 mM, Tween-20 0.01% and mercaptoethanol 7.5 mM at pH 7.00. The compounds were dissolved in dimethyl sulphoxide (DMSO) to a final concentration of 100 mM. Various concentrations were made up in DMSO and mixed with the substrate (GSK-3 peptide) solution (to a final concentration 20 uM) described in the above section along with rabbit or human GSK-3α and GSK-3β (final concentration 0.5 uM/mL enzyme). The reactions were initiated with the addition of [γ-33P] ATP (500 cpm/pmole) spiked into a mixture of ATP (final concentration of 10 uM). After 30 minutes at room temperature the reaction was terminated by the addition of 10 uL of H3PO4/O.OP/0 Tween-20 (2.5%). A volume (10 uL) of the mixture was spotted onto P-30 phosphocellulose paper (Wallac & Berthold, EG&G Instruments Ltd, Milton Keynes). The paper was washed four times in H3PO4 (0.5%), 2 minutes for each wash, air dried and the radioactive phosphate incorporated into the synthetic glycogen synthase peptide, which binds to the P-30 phosphocellulose paper, was counted in a Wallac microbeta scintillation counter Analysis of Data: Values for IC50 for each inhibitor were calculated by fitting a four-parameter logistic curve to the model: cpm=lower+(upper-lower)/(I+(concentration IC50)). |
| Affinity data for this assay | |
|---|---|
| If you find an error in this entry please send us an E-mail | |