A new multi-quantum version of the HBHA(CBCACO)NH experiment with enhancedsensitivity for partially deuterated samples

A new multi-quantum version of the HBHA(CBCACO)NH experiment for partially deuterated protein samples is presented. The method is based on the signifi cant reduction of the proton and carbon relaxation rates due to multi-quant um delays in highly deuterated proteins recently published by our group. Th e introduction of a multi-quantum period in the coherence transfer pathway of the HBHA(CBCACO)NH experiment yields a dramatic increase of sensitivity- on average 46% with a 75% deuterated sample of the homodimeric 31 kDa E. co li IIPMAN domain. Additional resolution in the proton dimension can be achi eved by a double time shared approach keeping the H-1 single-quantum period at a minimum.. (C) 1999 academic Press.