These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Electrochemical assay of proteinase inhibitors using polycation-sensitive membrane electrode detection.
    Author: Badr IH, Ramamurthy N, Yang VC, Meyerhoff ME.
    Journal: Anal Biochem; 1997 Jul 15; 250(1):74-81. PubMed ID: 9234901.
    Abstract:
    A simple and sensitive electrochemical method suitable for real time detection of trypsin-like proteinase inhibitors is described. The method is based on utilizing a protamine (a polycationic substrate for trypsin-like proteinases)-sensitive membrane electrode to monitor, potentiometrically, the initial rate of protamine decomposition upon the addition of a proteinase-antiproteinase test solution. In the presence of proteinase inhibitors, the initial rate of change in electromotive force is dependent on the concentration of proteinase inhibitor in the sample solution. The feasibility of this new assay method is demonstrated by detecting four inhibitors of trypsin-like proteinases: alpha1-antiproteinase inhibitor, alpha2-macroglobulin, aprotinin, and soybean inhibitor, using trypsin as the indicator proteinase. The efficacy of inhibition by each species, as expressed by I50 values (concentration of the inhibitor that induces 50% of the maximum proteinase inhibition), is shown to correlate well with literature values for the association constant of the proteinase-antiproteinase complex (k[assoc]). The proposed electrochemical assay for aprotinin is examined further using trypsin, plasmin, and kallikrein as the proteinase indicator reagents. It is found that the trypsin-aprotinin system offers the highest sensitivity and lowest detection limit for aprotinin detection. Application of the proposed method for measuring aprotinin in pretreated plasma samples is also reported.
    [Abstract] [Full Text] [Related] [New Search]