Abstract: The cloning of a truncated Arabidopsis gene expressing squalene synthase, as well as the expression and purification of the squalene synthase, are described. Also described herein is a fluorescent assay using squalene synthase that is amenable to high-throughout use, particularly for studying the regulation of isoprenoid synthesis and identifying squalene synthase inhibitors and promoters. As the formation of squalene is stoichiometric with the depletion of NADPH, the activity of squalene synthase can be evaluated by following the NADPH concentration over time. Squalene synthase activity is determined by combining FPP, NADPH, squalene synthase and a magnesium ion cofactor to form a reaction mixture under conditions suitable for squalene formation, optionally in the presence of a compound being analyzed for its ability to inhibit or promote squalene synthase. The concentration of NADPH over time is determined by subjecting the reaction mixture to UV light and detecting fluorescent light emission.

Abstract: Immunocompentent phage display libraries, specific B-cells, lymphocytes, antibodies and methods for their preparation, useful for high throughput screening and other useful applications in proteomics are described.

Abstract: Novel DNA and enzymes such as Plant Thioredoxin-Porphobilinogen Synthase (T-PPS) or Plant Porphobilinogen Synthase (PPS), together with novel compositions thereof and methods using such enyzmes are claimed.

Abstract: The present invention provides a novel method to purify green-plant phytochrome; the production of hybridoma cell lines secreting monoclonal antibodies specific for green-plant phytochrome and that do not cross-react significantly with etiolated-plant phytochrome; a partial amino acid sequence for an immunoaffinity-purified green-plant phytochrome; oligonucleotide probes for cloning green-phytochrome genes from plant genomic DNA and cDNA libraries; and cloned green-phytochrome genes and cDNA.