Natural-abundance nitrogen-15 NMR studies of turkey ovomucoid third domain. Assignment of peptide nitrogen-15 resonances to the residues at the reactive site region via proton-detected multiple-quantum coherence. Ortiz-Polo, Gilberto; Krishnamoorthi, R.; Markley, John L.; Live, David H.; Davis, Donald G.; Cowburn, David. Coll. Agric. Life Sci., Univ. Wisconsin, Madison, WI, USA. J. Magn. Reson. (1986), 68(2), 303-310.

Abstract

Heteronuclear 2-dimensional 1H{15N} multiple-quantum (MQ) spectroscopy was applied to a protein sample at natural abundance: ovomucoid 3rd domain from turkey (Meleagris gallopavo), a serine proteinase inhibitor of 56 amino acid residues. Peptide amide 1H NMR assignments obtained by 2-dimensional 1H{1H} NMR methods led to identification of the corresponding 1H{15N} MQ coherence cross peaks. From these, 15N NMR chem. shifts were detd. for several specific backbone amide groups of amino acid residues located around the reactive site region of the inhibitor. Amide 15N chem. shifts, which are readily obtained in this way, may serve as sensitive probes for conformational studies of proteins.