Open AccessStructure and Antigenicity of Hen Egg‐White Lysozyme Fragments
Author(s) -
Matthyssens Gaston E.,
Kanarek Louis
Publication year - 1974
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1974.tb03421.x
Subject(s) - lysozyme , circular dichroism , chemistry , peptide , antigenicity , stereochemistry , molecule , tyrosine , salt bridge , disulfide bond , biochemistry , antibody , biology , mutant , organic chemistry , gene , immunology
Purification of a lysozyme‐digest resulted in the isolation of two main regions of the molecule, namely sequence (57—107) denoted loop fragment (see the accompanying paper), and sequence (1—27) linked to sequence (122—129) through disulfide bridge I—VIII (Jollès et al. , 1963), denoted NC‐peptide. Inhibition of lysozyme‐anti‐lysozyme precipitation showed that NC‐peptide reacted with about 10% of all goat anti‐lysozyme antibodies. It was suggested that these antibodies react with a conformation‐dependent determinant including tyrosine 20 and 30. In water or in aqueous salt solution, NC‐fragment retained about 20% of its “native” alpha‐helical amount ( i.e. the amount of helicity this fragment possesses when integrated in the lysozyme‐molecule). Reduction and alkylation of the I—VIII disulfide bridge abolished most of the spatial conformation, as was obvious from the circular dichroism curve isolated N‐peptide. Long‐range interactions between the N and C terminal parts of the molecule, therefore, seem to stabilize the native lysozyme molecule.