Abstract: Short enzyme donor fragments of ?-galactosidase are provided of not more than 40 amino acids, where the short fragments are used as a label and may be substituted with a wide variety of organic compounds, particularly polypeptides having independent functional activity. The enzyme donor finds use in competitive and non-competitive assays, monitoring intracellular events, or other processes where a sensitive non-interfering label is desired.

Abstract: Systems, including methods and reagents, for identifying enzyme inhibitors. The systems employ a conjugate of a known inhibitor of a target enzyme and an enzyme donor, an enzyme acceptor that binds to the enzyme donor to form an active indicator-enzyme complex, and a detectable substrate for the indicator enzyme. The assay is performed by combining the candidate agent, the conjugate of the known inhibitor and enzyme donor, the enzyme acceptor, and the substrate under binding conditions, where the candidate compound competes with the conjugate for the target enzyme. By measuring the rate of product formation or substrate depletion catalyzed by the indicator enzyme, the inhibitory activity of the candidate compound can be determined. The methodology is particularly applicable for target enzymes that have substrates or products that are difficult to synthesize and/or detect, such as kinases and phosphatases.

Abstract: Methods are provided for the fabrication of polymeric microchannel structures having enclosed microchannels of capillary dimension. The microchannel structures are constructed of a base plate and a cover, sealed together. Microchannel structures having walls of a plastic material are formed in a generally planar surface of at least the base plate. The cover has at least one generally planar surface, and the microchannel structures are enclosed by bonding the planar surfaces of the cover and the base plate together. In some embodiments the surfaces of the cover and base plate are both of plastic material, and are directly thermally bonded. In some embodiments a bonding material is applied to one of the surface prior to bringing the surfaces together. Suitable bonding materials are disclosed.

Abstract: Immunoaffinity purifications are performed using non-aqueous media, desirably, a small amount of an aqueous buffered medium, and, optionally, a surfactant. Hydrophobic ligands can be extracted from samples, immunoaffinity purified and eluted to provide a substantially pure product.

Abstract: Enhanced resistance to glyphosate, an inhibitor of the aromatic amino acid biosynthesis pathway, is imparted to a glyphosate sensitive host. A mutated aroA gene is employed which expresses 5-enolpyruvyl-3- phosphoshikimate synthase (EC: 2.5.1.19) (ES-3-P synthase). Methods are provided for obtaining the aroA mutation which provides the enzyme resistant to inhibition by glyphosate, means for introducing the structural gene into a sensitive host, as well as providing a method of producing the enzyme.The E. coli strain C600(pPMG1) has been deposited at the A.T.C.C. on Dec. 14, 1982 and given A.T.C.C. Accession No. 39256.

Abstract: Method for preparing peptides free of undesired amino acids or amino acid sequences employing site specific receptors and proteases to cleave unprotected enzymatically hydrolyzable bonds.

Abstract: Methods are provided for modulating Ligand-Receptor interactions by binding of molecules at two epitopes of a receptor, where the epitopes are in relatively close special relationship. By providing for inhibition of changes in conformation of the receptor, where the inhibition is due to steric interactions or molecular bridging between the two epitopic sites, Ligand-Receptor interactions may be modulated. The modulation of Ligand-Receptor interactions has application to diagnostic assays, modulation of cellular activity, and modulation of the physiological activity of macromolecular compounds.

Abstract: Methods are provided for rapidly determining a number of parameters in a few determinations. Particularly, the method is applicable to blood typing, determining the blood type as to the ABO and Rh type, as well as the determination of isoantibodies to the antigens. The method employs fluorescent particles having a plurality of fluorescers, where the presence or absence of light emission of a particular wavelength can be determined.