Conformational stability of ribonuclease T1 determined by hydrogen-deuterium exchange

Conformational stability of ribonuclease T1 determined by hydrogen-deuterium exchange.

The hydrogen-deuterium exchange kinetics of 37 backbone amide residues in RNase T1 have been monitored at 25, 40, 45, and 50 degrees C at pD 5.6 and at 40 and 45 degrees C at pD 6.6. The hydrogen exchange rate constants of the hydrogen-bonded residues varied over eight orders of magnitude at 25 degrees C with 13 residues showing exchange rates consistent with exchange occurring as a result of g...

Investigation of ribonuclease T1 folding intermediates by hydrogen-deuterium amide exchange-two-dimensional NMR spectroscopy.

The rate of hydrogen bond formation at individual amino acid residues in ribonuclease T1 (RNase T1) has been investigated by the hydrogen-deuterium exchange-2D NMR (HDEx-2D NMR) technique (Udgaonkar & Baldwin, 1988; Rder et al., 1988) to gain insight into the mechanism and pathways of protein folding. The HDEx-2D NMR technique combines rapid mixing and 2D NMR methods to follow the protection of...

Structure of a hydrophobically collapsed intermediate on the conformational folding pathway of ribonuclease A probed by hydrogen-deuterium exchange.

The unfolded state of disulfide-intact bovine pancreatic ribonuclease A is a heterogeneous mixture of unfolded species which have different X-Pro peptide bond conformations. One of these unfolded species, labeled Uvf, has all its X-Pro peptide bonds in the native conformation. Therefore, the refolding of Uvf is a purely conformational folding process which is not complicated by cis-trans X-Pro ...

Measuring the conformational stability of a protein by hydrogen exchange.

Local conformational stability of HIV-1 gp120 in unliganded and CD4-bound states as defined by amide hydrogen/deuterium exchange.

The binding reaction of the HIV-1 gp120 envelope glycoprotein to the CD4 receptor involves exceptional changes in enthalpy and entropy. Crystal structures of gp120 in unliganded and various ligand-bound states, meanwhile, reveal an inner domain able to fold into diverse conformations, a structurally invariant outer domain, and, in the CD4-bound state, a bridging sheet minidomain. These studies,...