UV-vis. absorption and CD spectral data indicate that the minimum amino acid sequence in the N-terminal segment of the light-harvesting (LH) polypeptides of photosynthetic bacteria necessary for the LH1-type complex-formation was that of the type 2, of our synthetic hydrophobic polypeptides (Scheme 2). Stable BChl a complex in the presence of a 2alpha-helix polypeptide with disulfide linkage, was obtained in lipid bilayers as well as in n-octyl-beta-D-glucopyranoside (OG) micelles, analogous to the subunit complex, B820, of the LH I complex of photosynthetic bacteria.