Open AccessConformation of thymosin β 4 in water determined by NMR spectroscopy
Author(s) -
CZISCH Michael,
SCHLEICHER Michael,
HÖRGER Susanne,
VOELTER Wolfgang,
HOLAK Tad A.
Publication year - 1993
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1993.tb18382.x
Subject(s) - chemistry , random coil , crystallography , nuclear magnetic resonance spectroscopy , thymosin , alpha helix , stereochemistry , peptide , aqueous solution , helix (gastropod) , population , circular dichroism , biochemistry , organic chemistry , biology , ecology , sociology , snail , demography
The conformational preferences of a 43‐amino‐acid G‐actin‐binding peptide, thymosin β 4 , in water at 1, 4 and 14°C, and at pH 3.0 and 6.5 were studied by NMR. NMR showed that thymosin β 4 lacks a uniquely folded conformation in water. However, some preferential α‐helical conformations of thymosin β 4 can be observed in aqueous solutions. The segment at residues 5–16 showed characteristic interactions for conformations in both the β‐strand and α‐helical regions of the ø‐Ψ space, based on strong C α H( i )‐NH( i +1) interactions and NH‐NH, C α H( i )‐NH( i +3), and C α H( i )‐C β H( i +3) interactions, respectively. At 1–4°C, another segment at residues 31–37 also shows both β and α conformations, forming however a less well‐defined helix than the segment at residues 5–16. At 14°C, the conformational population of the helix at positions 5–16 is shifted more towards the random and turn‐like structures, whereas the segment at positions 31–37 becomes exclusively a random coil.