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Identification of the 1 H resonances of valine and leucine residues in dihydrofolate reductase by using a combination of selective deuteration and two‐dimensional correlation spectroscopy
Author(s) -
Searle M.S.,
Hammond S.J.,
Birdsall B.,
Roberts G.C.K.,
Feeney J.,
King R.W.,
Griffiths D.V.
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)80070-9
Subject(s) - valine , dihydrofolate reductase , chemistry , lactobacillus casei , leucine , stereochemistry , nuclear magnetic resonance spectroscopy , amino acid , crystallography , enzyme , biochemistry , fermentation
Lactobacillus casei dihydrofolate reductase ( M r , 18500) contains 16 valine and 14 leucine residues. By comparing the 2D COSY NMR spectra of normal and [γ‐ 2 H 6 ]valine enzyme we have been able to identify all 60 methyl resonances from these residues, and to connect the pairs arising from the same residue. This pairing of the methyl resonances was aided by the examination of the 2D RELAY spectrum which also allowed the C α H resonances (and hence the complete spin systems) of 14 of the valine residues to be identified. The combination of selective deuteration with 2D NMR techniques is shown to be a powerful general method for resolving 1 H resonances in the complex spectra of proteins and for assigning them to amino‐acid type.