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Synthesis and secretion of procathepsin B and cystatin C by human bronchial epithelial cells in vitro: modulation of cathepsin B activity by neutrophil elastase

Burnett, D; Abrahamson, Magnus LU ; Devalia, J L; Sapsford, R J; Davies, R J and Buttle, D J (1995) In Archives of Biochemistry and Biophysics 317(1). p.305-310
Abstract
Procathepsin B and cystatin C are found in human lung secretions. We investigated the capacity of human bronchial epithelial cells to synthesize and secrete these proteins. Immunoprecipitation of [35S]methionine-labeled proteins from cultured bronchial epithelial cell lysates, followed by denaturing gel electrophoresis and autoradiography, showed the presence of newly synthesized procathepsin B of M(r) 42,000; no mature form was detected. Cathepsin B in conditioned medium from epithelial cells was tagged with benzyloxycarbonyl-125I-tyrosyl-alanine-diazomethane before and after treatment of the medium with neutrophil elastase. Control medium again showed a predominant form of cathepsin B with a M(r) of 42,000, but upon treatment with... (More)
Procathepsin B and cystatin C are found in human lung secretions. We investigated the capacity of human bronchial epithelial cells to synthesize and secrete these proteins. Immunoprecipitation of [35S]methionine-labeled proteins from cultured bronchial epithelial cell lysates, followed by denaturing gel electrophoresis and autoradiography, showed the presence of newly synthesized procathepsin B of M(r) 42,000; no mature form was detected. Cathepsin B in conditioned medium from epithelial cells was tagged with benzyloxycarbonyl-125I-tyrosyl-alanine-diazomethane before and after treatment of the medium with neutrophil elastase. Control medium again showed a predominant form of cathepsin B with a M(r) of 42,000, but upon treatment with neutrophil elastase this protein was converted to a M(r) of 38,000, similar to the active form previously found in lung secretions, and cathepsin B activity was generated. The medium also contained the cathepsin B inhibitor, cystatin C, but cystatins A, B, S, SN, SA, and kininogen were not detected. After removal of cystatin C from the medium, elastase was still required to activate procathepsin B. These results suggest that bronchial epithelial cells are a source of procathepsin B and cystatin C in lung secretions. Cleavage both of cystatin C and procathepsin B by neutrophil elastase is essential for the generation of cathepsin B activity in the medium. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Archives of Biochemistry and Biophysics
volume
317
issue
1
pages
305 - 310
publisher
Academic Press
external identifiers
  • pmid:7872798
  • scopus:0028939165
ISSN
0003-9861
DOI
10.1006/abbi.1995.1167
language
English
LU publication?
yes
id
df68ca40-2e6f-4786-937f-0190212b50e1 (old id 1108943)
date added to LUP
2008-07-25 11:23:24
date last changed
2017-01-01 04:25:24
@article{df68ca40-2e6f-4786-937f-0190212b50e1,
  abstract     = {Procathepsin B and cystatin C are found in human lung secretions. We investigated the capacity of human bronchial epithelial cells to synthesize and secrete these proteins. Immunoprecipitation of [35S]methionine-labeled proteins from cultured bronchial epithelial cell lysates, followed by denaturing gel electrophoresis and autoradiography, showed the presence of newly synthesized procathepsin B of M(r) 42,000; no mature form was detected. Cathepsin B in conditioned medium from epithelial cells was tagged with benzyloxycarbonyl-125I-tyrosyl-alanine-diazomethane before and after treatment of the medium with neutrophil elastase. Control medium again showed a predominant form of cathepsin B with a M(r) of 42,000, but upon treatment with neutrophil elastase this protein was converted to a M(r) of 38,000, similar to the active form previously found in lung secretions, and cathepsin B activity was generated. The medium also contained the cathepsin B inhibitor, cystatin C, but cystatins A, B, S, SN, SA, and kininogen were not detected. After removal of cystatin C from the medium, elastase was still required to activate procathepsin B. These results suggest that bronchial epithelial cells are a source of procathepsin B and cystatin C in lung secretions. Cleavage both of cystatin C and procathepsin B by neutrophil elastase is essential for the generation of cathepsin B activity in the medium.},
  author       = {Burnett, D and Abrahamson, Magnus and Devalia, J L and Sapsford, R J and Davies, R J and Buttle, D J},
  issn         = {0003-9861},
  language     = {eng},
  number       = {1},
  pages        = {305--310},
  publisher    = {Academic Press},
  series       = {Archives of Biochemistry and Biophysics},
  title        = {Synthesis and secretion of procathepsin B and cystatin C by human bronchial epithelial cells in vitro: modulation of cathepsin B activity by neutrophil elastase},
  url          = {http://dx.doi.org/10.1006/abbi.1995.1167},
  volume       = {317},
  year         = {1995},
}