Studies on unfolded beta-microglobulin at C-terminal in dialysis-related amyloidosis.
BACKGROUND
In 1997, Stoppini et al reported that monoclonal antibody specific to the C-terminal 92-99 of beta(2)-microglobulin (beta(2)m) had been capable of inhibiting fibrillogenesis of beta(2)m in vitro. Meanwhile, recent studies have indicated that an acidifying procedure can unfold conformation of the precursor protein, leading to fibril formation of beta(2)m as well as a transthyretin.


METHODS
We thus prepared monoclonal antibody specific to the C-terminal 92-99 (mAb 92-99), and investigated its reactivity in plasma ultrafiltrate and amyloid tissues from 18 hemodialysis patients with dialysis-related amyloidosis (DRA).


RESULTS
beta(2)m extracted from ultrafiltrate showed no reaction for mAb 92-99, whereas acidified beta(2)m from ultrafiltrate showed a reaction for mAb 92-99. Similarly, a homogenate of carpal amyloid tissues showed a strong reaction for mAb 92-99 on immunoblotting. Immunohistochemical study showed also a distinct staining for mAb 92-99 in 7 Congophilic specimens from DRA patients. More interestingly, staining for mAb 92-99 could be found in most, though not all, non-Congophilic tissues.


CONCLUSIONS
This study demonstrates that the monoclonal antibody specific to the C-terminal 92-99 of beta(2)m can detect the conformational intermediate in amyloidogenesis of beta(2)m ex vivo, and demonstrates that an unfolded beta(2)m at C-terminal could be found not only in Congophilic area but even in non-Congophilic area as well.
Motomiya
Yoshihiro
Y
Suiyukai Clinic, Nara, Japan. motomiya@silver.ocn.ne.jp
Ando
Yukio
Y
Haraoka
Katsuki
K
Sun
Xuguo
X
Morita
Hiroyuki
H
Amano
Izumi
I
Uchimura
Tomonori
T
Maruyama
Ikuro
I
D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D000686:Amyloidosis / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D002349:Carpal Tunnel Syndrome / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D002942:Circular Dichroism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D008875:Middle Aged; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D011489:Protein Denaturation; D017510:Protein Folding; D006435:Renal Dialysis / Q000009:adverse effects*; D001613:beta 2-Microglobulin / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D010446:Peptide Fragments; D001613:beta 2-Microglobulin