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Conformational Correlates of the Epitopes of Human Myelin Basic Protein Peptide 80–89
Author(s) -
Whitaker John N.,
Moscarello Mario A.,
Herman Paula K.,
Epand Richard M.,
Surewicz Witold K.
Publication year - 1990
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1990.tb04171.x
Subject(s) - epitope , myelin basic protein , peptide , chemistry , polyclonal antibodies , circular dichroism , protein secondary structure , biochemistry , linear epitope , protein structure , antigen , myelin , biology , immunology , neuroscience , central nervous system
Different epitopes residing within the decapeptide of residues 80–89 of human myelin basic protein (MBP) exist in the MBP‐like material detected in human CSF and urine. In the present study, the structure of human MBP peptide 80–89 was examined by a combination of physical measurements and correlated with its varying immunochemical reaction with three polyclonal antisera. At least two epitopes are present in the decapeptide. Progressive shortening and reduction in net negative charge of MBP peptide 80–89 to form peptides 81–89, 82–89, 83–89, and 84–89 revealed an epitope not present in intact MBP. Circular dichroism and Fourier‐transform infrared of these MBP peptides in water demonstrated random structure that was partially changed to β‐structure in the shorter peptides. In methanol, used as a model for a lipid environment, the random structure was diminished and was replaced by α‐helix and β‐structure, especially in the shorter peptides. The findings indicate that the range of epitopes present in this decapeptide is influenced by conformation, which, unexpectedly, becomes progressively less random as the peptide becomes smaller, especially in a hydrophobic environment. This behavior has implications for the immunochemical detection of small antigens or antibodies to them in tissue extracts or body fluids.