Tendamistat (12-26) fragment. NMR characterization of isolated beta-turn folding intermediates.
In order to determine whether regions of a protein that are turns in the native structure are able to maintain such a structure when isolated, we have studied the conformational properties of various peptide fragments corresponding to the 12-26-peptide region of the alpha-amylase inhibitor tendamistat, by NMR. Amide solvent accessibility, NOE spectroscopy (NOESY) and rotating-frame NOE spectroscopy (ROESY) data strongly support the conclusion that the 12-26 and 15-23 peptides adopt in aqueous solution, a set of turn-like structures located around the central region of their corresponding polypeptidic chains, the same region where a beta turn exists in the native protein. Such a set of structures are destabilized when one residue located within the native beta turn of the 15-23 peptide is modified Trp18----Ser. Our results indicate that the tendency to bend in a predetermined region of a protein chain seems to exist from the very beginning of the folding process and therefore it could drive the folding instead of being a consequence of the tertiary assembly of the protein.
Blanco
F J
FJ
Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
Jiménez
M A
MA
Rico
M
M
Santoro
J
J
Herranz
J
J
Nieto
J L
JL
D000577:Amides / Q000737:chemistry; D000595:Amino Acid Sequence; D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics*; D010455:Peptides / Q000737:chemistry / Q000235:genetics*; D011487:Protein Conformation; D013696:Temperature
D000577:Amides; D010446:Peptide Fragments; D010455:Peptides; C030526:tendamistate