The Core is intended to provide necessary support for the research work in this program in two areas, firstly in providing biochemical and molecular biological infrastructure for all four projects and secondly in supporting the infrastructure of the NMR and X-ray efforts, in proportion to the usage that this program is anticipated to make of these facilities. Many of the hybridomas and immunoglobulins necessary for the two structural projects will be provided by the core, and it is anticipated that all four projects will rely heavily on the expertise of core personnel.