NH resonances of Ribonuclease S-peptide in aqueous solution. Low temperature n.m.r. study.
A detailed study of the NH resonances of Ribonuclease-S-peptide (1-19 N-terminal fragment of Ribonuclease A) has been carried out in H2O, pH 3.0, in the temperature range 1-31 degrees, and ionic strength 0-1 M. Individual assignments of all NH amide signals have been achieved by means of extensive double resonance experiments. The folding of S-peptide at low temperature has been monitored by examination of the several NH resonance parameters: first, the nonlinearity of chemical shift vs. temperature plots; second, the selective broadening observed for signals assigned to residues 3-13; and third, the decrease of 3JHNCH coupling constants belonging to this region of the polypeptide chain. All these results are in agreement with the formation of a folded structure at low temperature, which is similar to the one found for the S-peptide in the RNase S crystal.
Nieto
J L
JL
Rico
M
M
Santoro
J
J
Bermejo
J
J
D000577:Amides; D003080:Cold Temperature; D009682:Magnetic Resonance Spectroscopy; D010446:Peptide Fragments / Q000276:immunology*; D011487:Protein Conformation; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D012260:Ribonucleases; D012996:Solutions; D013373:Substance P / Q000276:immunology*
D000577:Amides; D010446:Peptide Fragments; D012996:Solutions; C023560:ribonuclease S-peptide; D013373:Substance P; C032292:substance P (6-11); D012260:Ribonucleases; D011761:Pyrrolidonecarboxylic Acid