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Sensitive and specific enzymatic assay for the determination of precursor forms of prostate-specific antigen after an activation step

Niemela, P; Lovgren, J; Karp, M; Lilja, Hans LU and Pettersson, K (2002) In Clinical Chemistry 48(8). p.1257-1264
Abstract
Background: The proteome of the serine protease prostate-specific antigen (PSA) and its enzymatic properties have been clarified only recently. We have developed a specific and sensitive method for the measurement of active PSA and used it to measure proPSA in blood. Methods: We used the synthetic peptide KGISSQY, which possesses a PSA-specific cleavage site, as substrate. To ascertain the specificity of the assay, we used an anti-PSA monoclonal antibody that captures known forms of PSA. An activation step enabled us to measure proPSA by converting it to mature, active PSA. Results: The detection limit of the optimized assay was 0.5 mug/L. In blood samples from patients, the activation step substantially increased the concentration of... (More)
Background: The proteome of the serine protease prostate-specific antigen (PSA) and its enzymatic properties have been clarified only recently. We have developed a specific and sensitive method for the measurement of active PSA and used it to measure proPSA in blood. Methods: We used the synthetic peptide KGISSQY, which possesses a PSA-specific cleavage site, as substrate. To ascertain the specificity of the assay, we used an anti-PSA monoclonal antibody that captures known forms of PSA. An activation step enabled us to measure proPSA by converting it to mature, active PSA. Results: The detection limit of the optimized assay was 0.5 mug/L. In blood samples from patients, the activation step substantially increased the concentration of active PSA, thus showing the presence of proPSA in the samples. ProPSA was 0-79% (median, 45%) of the amount of free PSA in 15 samples with total PSA concentrations of 5.3-423 mug/L. In samples obtained from three benign prostatic hyperplasia (BPH) patients after transurethal resection of the prostate, no significant increase in activity was detected after the activation step, thus showing that proPSA was not a portion of free PSA in plasma of BPH patients. Conclusions: Proforms of PSA are a considerable fraction of free PSA in the blood of patients with increased total PSA. The approach described can be used to study the diagnostic value of proPSA and active PSA in patients with BPH and prostate cancer. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Clinical Chemistry
volume
48
issue
8
pages
1257 - 1264
publisher
American Association for Clinical Chemistry
external identifiers
  • pmid:12142382
  • wos:000176996500018
  • scopus:0036325771
ISSN
0009-9147
language
English
LU publication?
yes
id
01eb1918-459d-4ef5-b93a-f446403e2f1c (old id 332786)
alternative location
http://www.clinchem.org/cgi/reprint/48/8/1257
date added to LUP
2007-11-19 15:06:53
date last changed
2017-01-01 04:23:45
@article{01eb1918-459d-4ef5-b93a-f446403e2f1c,
  abstract     = {Background: The proteome of the serine protease prostate-specific antigen (PSA) and its enzymatic properties have been clarified only recently. We have developed a specific and sensitive method for the measurement of active PSA and used it to measure proPSA in blood. Methods: We used the synthetic peptide KGISSQY, which possesses a PSA-specific cleavage site, as substrate. To ascertain the specificity of the assay, we used an anti-PSA monoclonal antibody that captures known forms of PSA. An activation step enabled us to measure proPSA by converting it to mature, active PSA. Results: The detection limit of the optimized assay was 0.5 mug/L. In blood samples from patients, the activation step substantially increased the concentration of active PSA, thus showing the presence of proPSA in the samples. ProPSA was 0-79% (median, 45%) of the amount of free PSA in 15 samples with total PSA concentrations of 5.3-423 mug/L. In samples obtained from three benign prostatic hyperplasia (BPH) patients after transurethal resection of the prostate, no significant increase in activity was detected after the activation step, thus showing that proPSA was not a portion of free PSA in plasma of BPH patients. Conclusions: Proforms of PSA are a considerable fraction of free PSA in the blood of patients with increased total PSA. The approach described can be used to study the diagnostic value of proPSA and active PSA in patients with BPH and prostate cancer.},
  author       = {Niemela, P and Lovgren, J and Karp, M and Lilja, Hans and Pettersson, K},
  issn         = {0009-9147},
  language     = {eng},
  number       = {8},
  pages        = {1257--1264},
  publisher    = {American Association for Clinical Chemistry},
  series       = {Clinical Chemistry},
  title        = {Sensitive and specific enzymatic assay for the determination of precursor forms of prostate-specific antigen after an activation step},
  volume       = {48},
  year         = {2002},
}