A novel method of preparing totally alpha-deuterated amino acids for selective incorporation into proteins. Application to assignment of 1H resonances of valine residues in dihydrofolate reductase.
The pyridoxal/2H2O exchange reaction of the alpha-CH of amino acids is known to be accompanied by racemisation: Thus by using a D-amino acid as the starting material any L-amino acid formed in the reaction will be essentially fully deuterated at its alpha-position. We have used this method to prepare alpha-deuterated L-valine and incorporated this biosynthetically into L. casei dihydrofolate reductase. A comparison of the alpha CH-NH fingerprint regions of COSY spectra of deuterated and normal DHFR complexes allows one to identify cross-peaks from 15 of the 16 valine residues.
Feeney
J
J
Laboratory of Molecular Structure, National Institute for Medical Research, London, UK.
Birdsall
B
B
Ostler
G
G
Carr
M D
MD
Kairi
M
M
D000596:Amino Acids / Q000378:metabolism*; D003903:Deuterium; D007553:Isotope Labeling / Q000379:methods*; D007780:Lacticaseibacillus casei / Q000201:enzymology; D009682:Magnetic Resonance Spectroscopy; D013762:Tetrahydrofolate Dehydrogenase / Q000096:biosynthesis* / Q000737:chemistry; D014633:Valine / Q000378:metabolism*
D000596:Amino Acids; D003903:Deuterium; D013762:Tetrahydrofolate Dehydrogenase; D014633:Valine