Androgen-sensitive human prostate cancer cells, LNCaP, produce both N-terminally mature and truncated prostate-specific antigen isoforms.
To characterize prostate-specific antigen (PSA) produced by cancer cells, different isoforms of PSA secreted by the human prostate cancer cells, LNCaP, were purified. LNCaP-PSA production was induced by synthetic androgen, R1881. LNCaP-PSA was separated into four pools. The molecular mass of LNCaP-PSA isoforms in these pools was 34 kDa under reducing conditions and 29 kDa under nonreducing conditions on SDS/PAGE. pI of LNCaP-PSA isoforms varied from 6.8 to 8.2. Pool A had the highest specific activity, 37 nmol/(min x mg). All the pools formed stable complexes with alpha1-antichymotrypsin and alpha2-macroglobulin. The pools contained 10-60% of N-terminally correctly processed LNCaP-PSA isoforms. According to the molecular modelling, the addition or deletion of two or four N-terminal amino acids could affect the three-dimensional structure and thereby remarkably reduce the enzyme activity of LNCaP-PSA.
Biocenter Oulu and WHO Collaborating Centre for Research on Reproductive Health, University of Oulu, Finland.
A
A
Herrala
R
R
Kurkela
M
M
Vihinen
N
N
Kalkkinen
P
P
Vihko
D000595:Amino Acid Sequence; D003196:Computer Graphics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008297:Male; D015741:Metribolone / Q000494:pharmacology; D008958:Models, Molecular; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D017430:Prostate-Specific Antigen / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D011471:Prostatic Neoplasms / Q000378:metabolism*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D012661:Semen / Q000737:chemistry; D045165:Testosterone Congeners / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D010446:Peptide Fragments; D011994:Recombinant Proteins; D045165:Testosterone Congeners; D015741:Metribolone; D017430:Prostate-Specific Antigen