Abstract: The invention provides a method to screen for a modulator of enzymatic activity comprising the step of monitoring the association or dissociation of a pair of polypeptides which can associate as a dimer. The polypeptide pair comprises a first polypeptide comprising detection means and a site of post-translational modification and a second polypeptide comprising detection means.

Abstract: The invention provides methods and compositions for monitoring enzymatic activity as a function of the interaction of modification dependant binding partner polypeptides. Association or dissociation of the binding partner polypeptides is dependant upon the addition or removal of a moiety to or from one or both of the binding partner polypeptides or upon proteolytic digestion of one or both of the binding partner polypeptides by a modifying enzyme.

Abstract: The invention relates to a method for determining the conformational state of a protein, comprising the steps of: a) providing a first binding partner which is capable of binding to the protein in a manner dependent on the conformational state of the protein and which generates a signal in a manner dependent on the binding of the first binding partner to the protein; and b) contacting the protein with the first binding partner and determining the conformational state of the protein by assessing the labelling of the protein by the binding of the first binding partner.

Abstract: The present invention relates to a polypeptide multimer comprising a first polypeptide having associated therewith a label and a second polypeptide, wherein a) at least one of the polypeptides is susceptible to protease digestion; b) association of the polypeptides to form a multimer is detectable via a signal emitted by the label; and c) digestion of at least one polypeptide results in dissociation of the multimer and modulation of the signal emitted by the label, and the method of detecting or monitoring the activity of a protease enzyme based on such a multimer.

Abstract: A method is provided for measuring in vivo in a transgenic non-human multicellular organism the activity of a cellular enzyme, which organism is transgenic by virtue of comprising one or more nucleic acid constructs encoding a binding domain and a binding partner thereof wherein: (i) the binding domain and/or binding partner comprise a site subject to post-translational modification by the cellular enzyme; (ii) modification of the site by the enzyme affects the interaction between the binding domain and the binding partner; and (iii) the binding domain and the binding partner each comprise a detectable label such that when the binding domain and binding partner interact, a detectable physical characteristic of one or both of the labels is altered, which method comprises measuring the interaction between the binding domain and the binding partner by measuring changes in the physical characteristic in one or more cells of the transgenic organism. A transgenic non-human multicellular organism is also provided.

Abstract: This invention relates to methods and compositions for monitoring the interaction of binding partners as a function of the addition or subtraction of a phosphate group to or from one of the binding partners by a protein kinase or phosphatase.

Abstract: This invention relates to methods and compositions for monitoring the interaction of binding partners as a function of the addition or subtraction of a phosphate group to or from one of the binding partners by a protein kinase or phosphatase.

Abstract: The invention provides an isolated polypeptide, or a fragment thereof, comprising a coiled-coil and an engineered site sufficient for the addition of a “moiety”, i.e., a group, that is one or more of a phosphate, ubiquitin, glycosyl or ADP-ribosyl moiety, wherein the polypeptide binds to a binding partner in a phosphorylation-, ubiquitination-, glycosylation- or ADP-ribosylation-dependent manner. The invention also relates to methods and kits utilizing an isolated polypeptide and its binding partner, which methods and kits permit monitoring of addition or removal of the one or more moieties.

Abstract: This invention relates to methods and compositions for monitoring enzymatic activity as a function of the the interaction of binding partners, wherein binding is dependent upon addition or subtraction of a chemical moiety to or from one of the binding partners by a protein modifying enzyme.