AMIDE PROTON-EXCHANGE MEASUREMENTS AS A PROBE OF THE STABILITY AND DYNAMICS OF THE N-TERMINAL DOMAIN OF THE RIBOSOMAL-PROTEIN L9 - COMPARISON WITH THE INTACT PROTEIN
L. Vugmeyster et al., AMIDE PROTON-EXCHANGE MEASUREMENTS AS A PROBE OF THE STABILITY AND DYNAMICS OF THE N-TERMINAL DOMAIN OF THE RIBOSOMAL-PROTEIN L9 - COMPARISON WITH THE INTACT PROTEIN, Protein science, 7(9), 1998, pp. 1994-1997
Amide H/D exchange rates have been measured for the N-terminal domain
of the ribosomal protein L9, residues 1-56. The rates were measured at
pD 3.91, 5.03, and 5.37. At pD 5.37, 18 amides exchange slowly enough
to give reliable rate measurements. At pD 3.91, seven additional resi
dues could be followed. The exchange is shown to occur by the EX2 mech
anism for all conditions studied. The rates for the N-terminal domain
are very similar to those previously measured for the corresponding re
gion in the full-length protein (Lillemoen J et al., 1997, J Mol Biol
268:482-493). In particular, the rates for the residues that we have s
hown to exchange via global unfolding in the N-terminal domain agree w
ithin the experimental error with the rates measured by Hoffman and co
workers, suggesting that the structure of the domain is preserved in i
solation and that the stability of the isolated domain is comparable t
o the stability of this domain in intact L9.