Characterization of a transthyretin-related amyloid fibril protein from cerebral amyloid angiopathy in type i familial amyloid polyneuropathy
Kametani, F.; Ikeda, S.; Yanagisawa, N.; Ishi, T.; Hanyu, N.
Journal of the Neurological Sciences 108(2): 178-183
ISSN/ISBN: 0022-510X PMID: 1517749 DOI: 10.1016/0022-510x(92)90048-p
Recently, it has been reported that transthyretin (TTR)-immunoreactive amyloid deposition with cerebral amyloid angiopathy in central nervous system is a common pathological finding in type I familial amyloid polyneuropathy (FAP). In the present study, we performed isolation and sequence analysis of TTR-related amyloid fibril protein from the meninges of a patient with type I FAP. Purified major amyloid fibril protein had a molecular weight of 15 kDa. Complete sequence analysis revealed that this amyloid fibril protein was a variant TTR with a single amino acid substitution of methionine for valine at position 30. This variant TTR is a previously unrecognized as cerebrovascular amyloid fibril protein. Furthermore, the patients with type I FAP are well known to have the variant TTR in the serum. These suggest that cerebrovascular amyloid fibril protein in type I FAP may derive from a serum precursor.