This research is aimed at elucidating the minimum set of interactions required to stabilize folded and partially folded protein domains. Attention will be focused on the molten globule state of alpha- lactalbumin, by preparing peptide models of critical regions of this protein and by developing novel techniques for probing long range interactions in partially folded proteins. These experiments will make use of stable spin labels and 2D NMR. These studies of partially folded states will be complemented by determining the interactions required to specify a unique folded structure in a novel three helix """"""""mini-domain"""""""", the E3/E1p domain of a B. Stearothermophilus protein.