Biomaterial Database

Immunochemical and molecular analysis of antigen binding to lipid anchored and soluble forms of an MHC independent human alpha/beta T cell receptor. 1994

A Buchwalder, and M S Krangel, and P Hao, and D J Diamond

Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, CA 91010.

We have constructed antigen-specific chimeric human T cell receptor (TCR) molecules deleted of the transmembrane domain and containing the signal sequence for the biosynthesis of the phosphatidyl inositol glycan (GPI) linkage. These membrane-anchored forms of the TCR alpha and beta chains have been expressed in non-T cells, and they are recognized by alpha or beta TCR specific monoclonal antibodies. We have utilized both immunochemical methods and flow cytometry to prove that the enzyme phosphatidylinositol phospholipase C (PI/PLC) is able to cleave the GPI anchored TCR as a heterodimer from the CHO cell surface. We have demonstrated that the alpha/beta TCR heterodimer on the surface of CHO cells will recognize and bind polymers containing fluorescein (FL-polymer), and the binding activity is completely eliminated by the enzyme, PI/PLC. Moreover, soluble forms of the alpha/beta heterodimer will bind tightly to FL substituted sepharose, which demonstrates the retention of biological activity by the TCR after solubilization. Molecular modelling of the putative antigen binding site of the alpha FL beta FL TCR was derived from the known atomic coordinates of eight different hapten or peptide specific antibodies. Mutagenesis of several residues predicted from the model to be important in FL binding gave results consistent with involvement of Ig equivalent CDR2 and CDR3 domains in the antigen binding pocket. Therefore, using a model hapten system in studying recognition of the TCR independent of MHC interactions, we conclude that amino acid residues located in similar positions within CDR domains as compared to the case of MHC restricted TCR recognition are used in the binding of either hapten or peptide antigens.

UI	MeSH Term	Description	Entries
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010727	Phosphoric Diester Hydrolases	A class of enzymes that catalyze the hydrolysis of one of the two ester bonds in a phosphodiester compound. EC 3.1.4.	Phosphodiesterase,Phosphodiesterases,Hydrolases, Phosphoric Diester
D011233	Precipitin Tests	Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.	Precipitin Test,Test, Precipitin,Tests, Precipitin
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D005452	Fluoresceins	A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.	Tetraiodofluorescein
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia