ABSTRACT: PROTEIN PRODUCTION AND INTERACTION CORE (CORE D) The Protein Production and Interaction Core (Core D) will be led by W. Sean Davidson and will be located in his laboratory at the University of Cincinnati. His lab has extensive and documented experience in all proposed Core services. The Core is designed to provide a consistent and cost-effective set of high quality protein and lipoprotein reagents to PPG investigators in furtherance of the goals of each Project. Core D also provides evaluations of protein:protein interactions by developing and implementing state-of-the-art cross-linking approaches for application across the PPG projects as well as continued technology development with the aim of improving the resolution of structural determinations. The Core will be heavily used by each of the Projects. The goals of Core D are: 1. To express, purify and distribute recombinant apolipoproteins and their mutants produced in bacteria. 2. To express and distribute PON1, CETP, apoA-II and ABCA1 and their mutants produced in eukaryotic cells. 3. To isolate, characterize and distribute lipoproteins and apolipoproteins isolated from human plasma. 4. To generate, characterize and distribute reconstituted HDL lipoproteins. 5. To perform chemical cross-linking analyses on individual proteins, enzymes, transfer proteins and lipoprotein complexes in synergy with the HDL Quantitation Core (Core C). 6. To develop innovative new cross-linking approaches aimed at increasing protein structure resolution.