Androgen-sensitive human prostate cancer cells, LNCaP, produce both N-terminally mature and truncated prostate-specific antigen isoforms

Eur J Biochem. 1998 Jul 15;255(2):329-35. doi: 10.1046/j.1432-1327.1998.2550329.x.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Computer Graphics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Male
  • Metribolone / pharmacology
  • Models, Molecular
  • Molecular Weight
  • Peptide Fragments / chemistry
  • Prostate-Specific Antigen / biosynthesis*
  • Prostate-Specific Antigen / chemistry
  • Prostate-Specific Antigen / isolation & purification
  • Prostatic Neoplasms / metabolism*
  • Protein Conformation*
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / isolation & purification
  • Semen / chemistry
  • Testosterone Congeners / pharmacology
  • Tumor Cells, Cultured

Substances

  • Peptide Fragments
  • Recombinant Proteins
  • Testosterone Congeners
  • Metribolone
  • Prostate-Specific Antigen