Open AccessA “Proportion Graph” Method for Measuring Binding Systems
Author(s) -
Baulieu Etienne E.,
Raynaud JeanPierre
Publication year - 1970
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1970.tb00931.x
Subject(s) - scatchard plot , law of mass action , ligand (biochemistry) , function (biology) , range (aeronautics) , chemistry , graph , binding site , biological system , mathematics , computer science , receptor , combinatorics , biochemistry , materials science , biology , evolutionary biology , composite material
A new graphical methodology is proposed to visualize and estimate the binding at equilibrium of small molecules in protein mixtures, providing each binding system is independent and follows the law of mass action. In many cases, the plots of Lineweaver‐Burk or Eadie‐Scatchard are found to be unsuitable. The method consists in plotting log [fraction bound] vs . log [total ligand]. The determination and statistical approximation of the binding parameters are performed and checked by means of a 360 IBM computer. Therefore instead of the linear method which may lead to arbitrary estimation, a non linear function covering the whole range of informations is used since nowadays computerized analysis is available. Theoretical and experimental examples are given for biological samples containing one or two systems of high affinity (“specific”), in the presence or absence of a system of low affinity and of a relatively large number of binding sites (“non‐specific”). The experimental material consists of steroid hormones and plasma or target tissue proteins.