Effects of methylamine and heparin on a rapid chromogenic assay of C1-esterase inhibitor in plasma
| Autor: | Jørgen Gram, Kathrine Overgaard, M Rånby, Jørgen Jespersen, S. Munkvad |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Clinical Biochemistry
Tripeptide Complement C1 Inactivator Proteins surgery Methylamines chemistry.chemical_compound Blood plasma medicine Humans complement Antigens Enzyme Inhibitors Serine protease chemistry.chemical_classification Autoanalysis Chromatography biology Heparin Chromogenic Methylamine Biochemistry (medical) Temperature α-macroglobulin Enzyme Chromogenic Compounds chemistry Enzyme inhibitor biology.protein medicine.drug |
| Zdroj: | Munkvad, S, Jespersen, J, Gram, J, Overgaard, K & Ranby, M 1990, ' Effects of methylamine and heparin on a rapid chromogenic assay of C1-esterase inhibitor in plasma ', Clinical Chemistry, vol. 36, no. 5, pp. 737-741 . https://doi.org/10.1093/clinchem/36.5.737 |
| ISSN: | 1530-8561 0009-9147 |
| Popis: | We describe a rapid assay of C1-esterase inhibitor (C1-inh) activity in plasma. After adding purified C1s serine protease (EC 3.4.21.42) in excess to plasma, we determine the residual C1s activity towards a new chromogenic tripeptide, CH3CO-Lys(CbO)-Gly-Arg-pNA. Optimal conditions include the addition of methylamine (final concentration 0.12 mol/L) to reduce the potential inhibitory capacity of alpha 2-macroglobulin towards C1s and the addition of heparin (final concentration 3000 int. units/L) to enhance the reaction of C1s with C1-inh. The correlation with C1-inh antigen concentrations in plasma was excellent. The estimated interassay CV was 4.3%, whereas the intra-assay CV was 2.0% for activity concentrations within the range of normal individuals (means +/- 2 SD: 70-124%), 1.3% at lower concentrations. The method is more convenient, rapid, and precise than previous methods, and C1-inh activity in plasma can be assessed within 30 min. We found that concentrations of C1-inh in plasma were low during open-heart bypass surgery. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|