Biomaterial Database

Polypeptide composition of paired helical filaments. 1989

Y Ihara, and J Kondo

Tokyo Metropolitan Institute of Gerontology, Japan.

Immunocytochemical studies using antibodies to cytoskeletal proteins have provided conflicting data on the components of paired helical filaments (PHF), due solely to immunological cross-reactivities. To avoid such ambiguity, we developed a protein chemical approach to the identification of the PHF components. After treatment with formic acid, PHF were digested with lysylendopeptidase and the resultant peptides were separated by HPLC. All major peaks were analysed for their amino acid compositions and sequences. From the PHF digest, proteolytic fragments of ubiquitin, tau and beta protein were sequenced. Ubiquitin in PHF appears to be in a conjugated form, while its target protein remains unidentified. Tau is integrated into PHF at the site of its carboxyl third. The presence of beta protein fragments is best interpreted as being due to contamination of amyloid filaments in the PHF preparation. Thus, ubiquitin and tau are the two definite components of PHF.

UI	MeSH Term	Description	Entries
D008869	Microtubule-Associated Proteins	High molecular weight proteins found in the MICROTUBULES of the cytoskeletal system. Under certain conditions they are required for TUBULIN assembly into the microtubules and stabilize the assembled microtubules.	Ensconsin,Epithelial MAP, 115 kDa,Epithelial Microtubule-Associate Protein, 115 kDa,MAP4,Microtubule Associated Protein,Microtubule Associated Protein 4,Microtubule Associated Protein 7,Microtubule-Associated Protein,Microtubule-Associated Protein 7,E-MAP-115,MAP1 Microtubule-Associated Protein,MAP2 Microtubule-Associated Protein,MAP3 Microtubule-Associated Protein,Microtubule Associated Proteins,Microtubule-Associated Protein 1,Microtubule-Associated Protein 2,Microtubule-Associated Protein 3,7, Microtubule-Associated Protein,Associated Protein, Microtubule,E MAP 115,Epithelial Microtubule Associate Protein, 115 kDa,MAP1 Microtubule Associated Protein,MAP2 Microtubule Associated Protein,MAP3 Microtubule Associated Protein,Microtubule Associated Protein 1,Microtubule Associated Protein 2,Microtubule Associated Protein 3,Microtubule-Associated Protein, MAP1,Microtubule-Associated Protein, MAP2,Microtubule-Associated Protein, MAP3,Protein 7, Microtubule-Associated,Protein, Microtubule Associated,Protein, Microtubule-Associated
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
D009419	Nerve Tissue Proteins		Proteins, Nerve Tissue,Tissue Proteins, Nerve
D009454	Neurofibrils	The delicate interlacing threads, formed by aggregations of neurofilaments and neurotubules, coursing through the CYTOPLASM of the body of a NEURON and extending from one DENDRITE into another or into the AXON.	Neurofibril
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
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
D000682	Amyloid	A fibrous protein complex that consists of proteins folded into a specific cross beta-pleated sheet structure. This fibrillar structure has been found as an alternative folding pattern for a variety of functional proteins. Deposits of amyloid in the form of AMYLOID PLAQUES are associated with a variety of degenerative diseases. The amyloid structure has also been found in a number of functional proteins that are unrelated to disease.	Amyloid Fibril,Amyloid Fibrils,Amyloid Substance,Fibril, Amyloid,Fibrils, Amyloid,Substance, Amyloid
D000911	Antibodies, Monoclonal	Antibodies produced by a single clone of cells.	Monoclonal Antibodies,Monoclonal Antibody,Antibody, Monoclonal
D014452	Ubiquitins	A family of proteins that are structurally-related to Ubiquitin. Ubiquitins and ubiquitin-like proteins participate in diverse cellular functions, such as protein degradation and HEAT-SHOCK RESPONSE, by conjugation to other proteins.	Ubiquitin-Like Protein,Ubiquitin-Like Proteins,Protein, Ubiquitin-Like,Proteins, Ubiquitin-Like,Ubiquitin Like Protein,Ubiquitin Like Proteins