Correlation between structural characteristics and immunological properties of the terpolymer L-glutamic acid60-L-alanine30-L-tyrosine10

Thèze, J.; Waltenbaugh, C.; Benacerraf, B.

European Journal of Immunology 7(2): 86-92

1977


ISSN/ISBN: 0014-2980
PMID: 68885
DOI: 10.1002/eji.1830070207
Accession: 068519250

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Abstract
The structure of the terpolymer L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) was investigated. GAT appears very heterogeneous in size as determined by gel filtration on a Sephadex G-100 column. A dramatic downward shift in the average MW is observed after gel filtration under denaturing conditions (Sepharose 6B, 6 M guanidine hydrochloride or polyacrylamide gel electrophoresis containing 0.1% sodium dodecyl sulfate). Under nondenaturing conditions, GAT is a multimeric structure; the dissociation of the structure is reversible. GAT was fractionated based on the size of the polypeptide chains under denaturing conditions. After removal of guanidine hydrochloride 3 fractions were obtained with .apprx. 100,000 (GAT fraction I), 45,000 (GAT fraction II) and < 10,000 (GAT fraction III) MW, respectively. The immunological properties of these 3 fractions were compared with those of unfractionated GAT. Fraction II resembles unfractionated GAT, showing similar immunogenicity in responder mice and suppressive properties in nonresponder animals. Fraction I is less immunogenic, otherwise it resembles unfractionated GAT. Fraction II is the most dissimilar of the 3 fractions investigated. It retains the suppressive activity of GAT but is unable to stimulate a specific antibody response in responder animals. GAT fraction III is not a general tolerogen and is specifically suppressive for nonresponder mice.