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Solution structure of salmon calcitonin
Author(s) -
Meyer JeanPhilippe,
Pelton John T.,
Hoflack Jan,
Saudek Vladimir
Publication year - 1991
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360310210
Subject(s) - chemistry , peptide , nuclear overhauser effect , residue (chemistry) , nuclear magnetic resonance spectroscopy , aqueous solution , crystallography , helix (gastropod) , amino acid , alanine , two dimensional nuclear magnetic resonance spectroscopy , stereochemistry , organic chemistry , biochemistry , ecology , snail , biology
Salmon calcitonin, a 32‐residue peptide with a 1–7 disulfide bridge, was synthesized by standard solid‐phase techniques, and studied by CD and two‐dimensional NMR experiments. The peptide was dissolved in pure trifluoroethanol (TFE) and in aqueous solutions containing various amounts of TFE. CD studies in pure TFE indicated the presence of an α‐helical structure comprising 40% of the constituent amino acids. This was fully confirmed by nmr. A detailed analysis was performed with the peptide in a 9 : 1 deuterated TFE/H 2 O mixture. A total of 365 nuclear Overhauser enhancements (154 intraresidual, 112 sequential and 99 long range) were compiled from the nuclear Overhauser enhancement spectroscopy spectra and used in the distance geometry calculations. The core of the peptide between residues 8 and 22 assumes an α‐helix like structure. The Cys 1–Cys 7 ring is well defined and in close association with the helix, while the C‐terminal decapeptide folds back toward the core, forming a loose loop.