A new nonamyloid transthyretin variant, G101S, detected by electrospray ionization/mass spectrometry. Mutations in brief no. 201. Online.
Familial amyloidotic polyneuropathy is caused by transthyretin (TTR) variants. The identification of new variants with and without amyloidosis may help to clarify the mechanism of amyloid fibril formation. We detected several variant TTRs from patients with and without symptoms of amyloidosis using mass spectrometry (MS). TTR was isolated by mixing test serum with anti-transthyretin antiserum, and the generated immunoprecipitate was analyzed by high performanced liquid chromatography/electrospray ionization (HPLC/ESI) MS. Variant TTRs showed extra peaks in addition to normal TTR peaks. A variant found in nonamyloid group was sequenced by HPLC/ESI tandem MS using peptides obtained by protelytic digestion of TTR and by DNA analysis. The structure was new, [G101S], and was found in a 74 years old Japanese male. This mutation results from substitution in a CpG hot spot. The substitution in the surface loop, 98-102, between F and G b-strands may not cause amyloid formation.
Kishikawa
M
M
Department of Clinical Pathology, Osaka Medical College, Japan.
Nakanishi
T
T
Miyazaki
A
A
Hatanaka
M
M
Shimizu
A
A
Tamoto
S
S
Ohsawa
N
N
Hayashi
H
H
Kanai
M
M
D000368:Aged; D017772:Amyloid Neuropathies / Q000235:genetics*; D005998:Glycine / Q000235:genetics; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D017354:Point Mutation; D011228:Prealbumin / Q000235:genetics* / Q000302:isolation & purification*; D020033:Protein Isoforms / Q000235:genetics / Q000302:isolation & purification*; D012694:Serine / Q000235:genetics
D011228:Prealbumin; D020033:Protein Isoforms; D012694:Serine; D005998:Glycine