[19F]-1H heteronuclear nuclear Overhauser effect studies of the acyl chain-binding site of acyl carrier protein.

[19F]-1H heteronuclear difference nuclear Overhauser effect experiments are performed on a sample of 5,5-difluorohexanoyl acyl carrier protein from Escherichia coli. Interaction of the fluorines at the 5-position of the acyl chain with protons on methyl groups of isoleucine 54 and alanine 59 is clearly indicated. The covalent attachment of the acyl chain via a prosthetic group to serine 36 and the known alpha-helix which exists from residues 36 to 51 greatly restrict the structural models which would allow acyl chain contact with residues 54 and 59.