Determination of cathepsin S abundance and activity in human plasma and implications for clinical investigation.
Anal Biochem
; 430(2): 130-7, 2012 Nov 15.
Article
em En
| MEDLINE
| ID: mdl-22922382
ABSTRACT
There is strong experimental evidence associating cathepsin S with the pathogenesis of atherosclerosis, with emerging data to support its role in diseases such as abdominal aortic aneurysm, obesity, and type 2 diabetes. To further our understanding of cathepsin S, we have developed a novel sandwich immunoassay to measure the mature form of cathepsin S in plasma (mean values from 12 healthy donors of 53±17ng/ml, range=39-102). We also developed a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay to measure in vitro cathepsin S activity to compare activity levels with the protein mass levels determined by enzyme-linked immunosorbent assay (ELISA). Interestingly, we observed that only 0.4 to 1.1% of circulating cathepsin S was enzymatically active. We subsequently demonstrated that the attenuated activity we observed resulted from binding between cathepsin S and its endogenous inhibitor cystatin C in plasma. These data were obtained through immunoprecipitation coupled with either Western blotting analysis or in-gel tryptic digestion and LC-MS/MS characterization of Coomassie-stained gel bands. Although many laboratories have explored the relationship between cathepsin S and cystatin C, this is the first study to demonstrate their association in human circulation, a finding that could prove to be important in furthering our understanding of cathepsin S biology.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ensaio de Imunoadsorção Enzimática
/
Catepsinas
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Cromatografia Líquida de Alta Pressão
/
Espectrometria de Massas em Tandem
Limite:
Humans
Idioma:
En
Revista:
Anal Biochem
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos