Proteomics of beta2-microglobulin amyloid fibrils.
Knowledge on the chemical structure of beta2-microglobulin in natural amyloid fibrils is quite limited because of the difficulty in obtaining tissue samples suitable for biochemical studies. We have reviewed the available information on the chemical modifications and we present new data of beta2-microglobulin extracted from non-osteotendinous tissues. beta2-microglobulin can accumulate in these compartments after long-term haemodialysis but rarely forms amyloid deposits. We confirm that truncation at the N-terminus is an event specific to beta2-microglobulin derived from fibrils but is not observed in the beta2-microglobulin from plasma or from the insoluble non-fibrillar material deposited in the heart and spleen. We also confirm the partial deamidation of Asn 17 and Asn 42, as well as the oxidation of Met 99 in fibrillar beta2-microglobulin. Other previously reported chemical modifications cannot be excluded, but should involve less than 1-2% of the intact molecule.
Stoppini
Monica
M
Dipartimento di Biochimica, Università degli Studi di Pavia, via Taramelli 3b, 27100 Pavia, Italy.
Mangione
Palma
P
Monti
Maria
M
Giorgetti
Sofia
S
Marchese
Loredana
L
Arcidiaco
Patrizia
P
Verga
Laura
L
Segagni
Siro
S
Pucci
Piero
P
Merlini
Giampaolo
G
Bellotti
Vittorio
V
D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry* / Q000302:isolation & purification; D000686:Amyloidosis / Q000503:physiopathology*; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D009206:Myocardium / Q000737:chemistry; D040901:Proteomics; D006435:Renal Dialysis / Q000009:adverse effects; D013154:Spleen / Q000737:chemistry; D001613:beta 2-Microglobulin / Q000737:chemistry* / Q000235:genetics
D000682:Amyloid; D001613:beta 2-Microglobulin