Conformation of surface exposed N-terminus part of bacteriorhodopsin studied by transferred NOE technique.

Interaction of the monoclonal antibody A5 raised against native bacteriorhodopsin (BR) with the synthetic peptide pGlu1-Ala-Gln-Ile-Thr-Gly-Arg7-NH2, corresponding to the amino acid sequence 1-7 was studied by transferred nuclear Overhauser effect (TRNOE) spectroscopy. The denaturing reagents and the specially designed pulse sequences which eliminate broad signals from the TRNOE spectra were used to favour evaluation of the TRNOE peaks. On the basis of the data obtained, the conformation of peptide bound with A5 was calculated. A model of the mutual arrangement of bacteriorhodopsin N-terminus and the first transmembrane alpha-helical segment 8-32 was proposed.