Senile seminal vesicle amyloid is derived from semenogelin I.
Senile seminal vesicle amyloid (SSVA), one of the most common forms of localized amyloidosis, is associated with the male aging process. Although it had been posited that the amyloidogenic component originated from exocrine cells and that, on the basis of immunohistochemistry, that the amyloid was composed of lactoferrin, the nature of SSVA was never established definitively. To address this issue, we have used our microanalytic techniques to characterize the structure of the congophilic green birefringent protein extracted from 5 such amyloid-containing specimens. Mass spectrometric analysis revealed that in all cases, the fibrils were composed mainly of polypeptide fragments identical in sequence to the N-terminal portion of the major secretory product of seminal vesicles, namely semenogelin I (SgI). Although lactoferrin was detected in 3 instances, the trace amount and seemingly intact form of this molecule indicated that it was not the amyloidogenic molecule. The SgI nature of the amyloid was confirmed through demonstration that the deposits were immunostained specifically with Sgl-reactive antibodies. The results of our research provide unequivocal evidence that SSVA is derived from SgI, and we provisionally designate this form of amyloidosis as ASgI.
Linke
Reinhold P
RP
Department of Structural Research, Max Planck-Institute of Biochemistry, Martinsried, Germany. linke@biochem.mpg.de
Joswig
Reinhild
R
Murphy
Charles L
CL
Wang
Shuching
S
Zhou
Hui
H
Gross
Ulrich
U
Rocken
Christoph
C
Westermark
Per
P
Weiss
Deborah T
DT
Solomon
Alan
A
D000368:Aged; D000375:Aging / Q000378:metabolism*; D000595:Amino Acid Sequence; D000682:Amyloid / Q000378:metabolism*; D000686:Amyloidosis / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D029607:Seminal Vesicle Secretory Proteins / Q000378:metabolism*; D012669:Seminal Vesicles / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D000682:Amyloid; D029607:Seminal Vesicle Secretory Proteins; C424482:seminal vesicle-specific antigen