A new multi-quantum version of the HBHA(CBCACO)NH experiment with enhanced sensitivity 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 significant reduction of the proton and carbon relaxation rates due to multi-quantum delays in highly deuterated proteins recently published by our group. The 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. coli IIPMAN domain. Additional resolution in the proton dimension can be achieved by a double time shared approach keeping the H-1 single-quantum period at a minimum.. (C) 1999 academic Press.