I would like to point out that HSQC could still be applied even in such a large protein. TROSY-HSQC has been successful in improving peaks in spectra of large protein. Typically the sample would need to be deuterated to see the full effect of TROSY, but even a partial deuteration can improve signal. We have run TROSY-spectra of a complex (75kDa) with no deuteration and that spectrum is much better than a normal HSQC spectrum.
Dan
