Biomaterial Database

Non-A beta component of Alzheimer's disease amyloid (NAC) is amyloidogenic. 1995

A Iwai, and M Yoshimoto, and E Masliah, and T Saitoh

Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla 92093-0624, USA.

The non-A beta component of Alzheimer's disease (AD) amyloid (NAC) was identified biochemically as the second major component in the amyloid purified from brain tissue of AD patients. NAC, derived from its 140 amino acid long precursor, NACP, is at least 35 amino acids long (NAC35) although its amino terminus is not definitely determined. An antiserum, anti-NAC-X1, was raised against the amino-terminal 9 amino acid sequence of NAC35 and purified on a peptide affinity column. This affinity-purified anti-NAC-X1 antibody immunostained amyloid in AD brain sections and recognized NAC35 but not NACP on Western or dot blot. In aqueous solutions, synthetic NAC35 self-aggregated in a time-, concentration-, and temperature-dependent manner. NAC35 was detected initially as a monomer with a molecular mass of 3500 Da but became aggregated as a function of time into a higher molecular mass component that could not migrate into the gel. The aggregate of NAC35 showed green-gold birefringence after Congo red staining when analyzed under polarized light and fiber-like structure when analyzed ultrastructurally. These results suggest that NAC can form amyloid after it has been cleaved out of its precursor and may be a crucial factor in amyloidosis in the AD brain.

UI	MeSH Term	Description	Entries
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
D003224	Congo Red	An acid dye used in testing for hydrochloric acid in gastric contents. It is also used histologically to test for AMYLOIDOSIS.	Red, Congo
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000544	Alzheimer Disease	A degenerative disease of the BRAIN characterized by the insidious onset of DEMENTIA. Impairment of MEMORY, judgment, attention span, and problem solving skills are followed by severe APRAXIAS and a global loss of cognitive abilities. The condition primarily occurs after age 60, and is marked pathologically by severe cortical atrophy and the triad of SENILE PLAQUES; NEUROFIBRILLARY TANGLES; and NEUROPIL THREADS. (From Adams et al., Principles of Neurology, 6th ed, pp1049-57)	Acute Confusional Senile Dementia,Alzheimer's Diseases,Dementia, Alzheimer Type,Dementia, Senile,Presenile Alzheimer Dementia,Senile Dementia, Alzheimer Type,Alzheimer Dementia,Alzheimer Disease, Early Onset,Alzheimer Disease, Late Onset,Alzheimer Sclerosis,Alzheimer Syndrome,Alzheimer Type Senile Dementia,Alzheimer's Disease,Alzheimer's Disease, Focal Onset,Alzheimer-Type Dementia (ATD),Dementia, Presenile,Dementia, Primary Senile Degenerative,Early Onset Alzheimer Disease,Familial Alzheimer Disease (FAD),Focal Onset Alzheimer's Disease,Late Onset Alzheimer Disease,Primary Senile Degenerative Dementia,Senile Dementia, Acute Confusional,Alzheimer Dementias,Alzheimer Disease, Familial (FAD),Alzheimer Diseases,Alzheimer Type Dementia,Alzheimer Type Dementia (ATD),Alzheimers Diseases,Dementia, Alzheimer,Dementia, Alzheimer-Type (ATD),Familial Alzheimer Diseases (FAD),Presenile Dementia,Sclerosis, Alzheimer,Senile Dementia
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
D017433	Protein Structure, Secondary	The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to ALPHA-HELICES; BETA-STRANDS (which align to form BETA-SHEETS), or other types of coils. This is the first folding level of protein conformation.	Secondary Protein Structure,Protein Structures, Secondary,Secondary Protein Structures,Structure, Secondary Protein,Structures, Secondary Protein