Abstract: This invention provides methods to determine the activity of methyltransferase enzymes which employ S-adenosylmethionine (SAM) as a substrate and transfer a methyl group to convert this substrate to S-adenosylhomocysteine (SAH), by measuring SAH conversion to AMP.

Abstract: Compositions, methods, and kits for detecting and monitoring kinase, phosphatase and protein post-translational modification activity are described. The compositions typically include a peptide, a detectable moiety, and a protease cleavage site. Modification of a peptide by a kinase, phosphatase or other protein post-translational modification alters the proteolytic sensitivity of the peptide, resulting in a change of a detectable property of the composition. Panel assays for determining substrates or modulators of kinase, phosphatase or other protein post-translational modification activity are also described.

Abstract: Compositions, methods, and kits for detecting and monitoring kinase, phosphatase and protein post-translational modification activity are described. The compositions typically include a peptide, a detectable moiety, and a protease cleavage site. Modification of a peptide by a kinase, phosphatase or other protein post-translational modification alters the proteolytic sensitivity of the peptide, resulting in a change of a detectable property of the composition. Panel assays for determining substrates or modulators of kinase, phosphatase or other protein post-translational modification activity are also described.

Abstract: Compositions, methods, and kits for detecting and monitoring post-translational modification activities, including kinase or phosphatase activities, are described. The compositions typically include a peptide, a first detectable moiety, a first binding member, and a protease cleavage site. Modification of a composition by a post-translational modification enzyme, such as a kinase or phosphatase, alters the proteolytic sensitivity of the peptide, resulting in a change of a detectable property of the composition when it is associated noncovalently with a probe composition that includes a second binding member and a second detectable moiety. Panel assays for determining substrates or modulators of enzymatic activities are also described.

Abstract: Compositions, methods, and kits for detecting and monitoring kinase or phosphatase activity are described. The compositions typically include a peptide, a detectable moiety, and a protease cleavage site. Modification of a peptide by a kinase or phosphatase alters the proteolytic sensitivity of the peptide, resulting in a change of a detectable property of the composition. Panel assays for determining substrates or modulators of kinase or phosphatase activity are also described.