The p-bromobenzamido chromophore as a circular dichroic probe for the assignement of the screw sense of helical peptides

The para-bromobenzoyl group linked to the N-terminus of a helical peptide chain turned out to be useful as a CD probe in the determination of the relationship between C-alpha-configuration of coded and non-coded alpha-amino acids and peptide helix screw sense in solution. The results of the present conformational investigation agree well with published crystal-state structural data on the same peptides obtained using X-ray diffraction where the para-bromobenzoyl group helped us to solve the phase problem by virtue of its heavy atom (bromine).