title: The combined use of selective deuteration and double resonance experiments in assigning the 1H resonances of valine and tyrosine residues of dihydrofolate reductase.
abstract: Selective deuteration is a general solution to the resolution problem which limits the application of double resonance experiments to the assignment of the 1H NMR spectra of proteins. Spin-decoupling and NOE experiments have been carried out on Lactobacillus casei dihydrofolate reductase and on selectively deuterated derivatives of the enzyme containing either [gamma-2H6]Val or [alpha, delta 2, epsilon 1-2H3]His, [alpha, delta 1, delta 2, epsilon 1, epsilon 2, zeta-2H6]Phe, [alpha, delta 1, epsilon 3, zeta 2, zeta 3, eta 2-2H6]Trp and [alpha, epsilon 1, epsilon 2-2H3]Tyr. When combined with ring-current shift calculations based on the crystal structure of the enzyme, these experiments allow us to assign 1H resonances of Val 61, Val 115, Tyr 46 and Tyr 68.
mesh_terms: D003903:Deuterium; D007780:Lacticaseibacillus casei / Q000201:enzymology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D011485:Protein Binding; D011487:Protein Conformation; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism*; D014443:Tyrosine / Q000032:analysis*; D014633:Valine / Q000032:analysis*
chemical_list: D014443:Tyrosine; D003903:Deuterium; D013762:Tetrahydrofolate Dehydrogenase; D014633:Valine