Anti-human prostasome MAB 78 binds to antigen distinct from PSA and PAP.
OBJECTIVE
The characteristics of an antigen corresponding to a monoclonal antibody (mAb 78) against human prostasomes were compared with prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP). The correspondence of Ag 78 to two other prostate-derived antigens, prostasin and peptide pGlu-Phe-Pro-NH2, were also considered.


METHODS
The immunoreactivity of mAb 78 and the cross-reactivity of mAb 78 with PSA and PAP were studied with immunohistochemical and enhanced chemiluminescence (ECL) Western blotting methods.


RESULTS
The mAb 78 did not bind to PSA blots, and anti-PSA antibody did not label prostasome blots. Neither did PSA and PAP impede the binding of mAb 78 onto prostasome blots nor to paraffin sections of prostate epithelium. Afer Western blots, mAb 78 bound diffusely to a band with a molecular weight of 35 kDa, but did not bind to PSA 933 kDa) or PAP (monomer 50 kDa, intact molecule 100 kDa) bands. From purified 35 kDa bands, three fractions were sequenced, which showed no similarities to PSA and PAP.


CONCLUSIONS
The Ag 78 is different from PSA and PAP, and probably also from prostasin and peptide pGlu-Phe-Pro-NH2. The mAb 78 can be used as a new marker for human prostasomes.
Jin
M
M
Department of Human Anatomy, Univeristy of Uppsala, Sweden.
Nilsson
B O
BO
Larsson
A
A
Hellman
U
U
Ronquist
G
G
D000135:Acid Phosphatase / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D003429:Cross Reactions; D004848:Epithelium; D006801:Humans; D008297:Male; D011467:Prostate / Q000276:immunology*; D017430:Prostate-Specific Antigen / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000135:Acid Phosphatase; D017430:Prostate-Specific Antigen