COMPARING CONFORMATIONS AT LOW-TEMPERATURE AND AT HIGH-VISCOSITY - CONFORMATIONAL STUDY OF SOMATOSTATIN AND 2 OF ITS ANALOGS IN METHANOL AND IN ETHYLENE-GLYCOL
P. Verheyden et al., COMPARING CONFORMATIONS AT LOW-TEMPERATURE AND AT HIGH-VISCOSITY - CONFORMATIONAL STUDY OF SOMATOSTATIN AND 2 OF ITS ANALOGS IN METHANOL AND IN ETHYLENE-GLYCOL, International journal of peptide & protein research, 44(5), 1994, pp. 401-409
The influence of low temperature and high viscosity on the conformatio
n of somatostatin and two of its analogues was investigated by H-1 NMR
in solution. The conformation of native somatostatin, a cyclic octape
ptide agonist DC13-116 and a linear octapeptide agonist were compared
in ethylene glycol at 303 K and in methanol at low temperature. The fi
rst goal of this study was to investigate if either low temperature or
high viscosity is the more important for the reduction of the conform
ational freedom. Secondly we wanted to compare the amount of informati
on concerning the conformation present in both solvents. A larger amou
nt of NOESY cross-peaks is observed in ethylene glycol at room tempera
ture compared to methanol at low temperature. This indicates that the
raising of the viscosity is a more important factor in reducing the fl
exibility of peptides than the lowering of the temperature. (C) Munksg
aard 1994.