This is a request for micro-scale protein sequencing equipment to extend the protein structure analysis facilities at Purdue University. Research projects on membrane proteins, polypeptide hormones, in vitro synthesized proteins, enzymes available in limited amounts, and developmentally and hormonally regulated proteins will all benefit greatly from the 100-fold increased sensitivity of the gas-phase sequencing system over conventional systems. The long-term experience of the P.I. in protein structure analysis, the well-established collaborative relationships between the investigators, and the convenient administrative structure of the protein structure facility at Purdue guarantee continued high productivity from the facility and ready access to investigators who need protein sequence analyses.