Identical independent sites for dye ligand on bovine serum albumin demonstrated by multivariate analysis |
| |
Authors: | Nakamaru Y Sato C |
| |
Affiliation: | Biological Institute, Graduate School of Science, Tohoku University, 980-8578, Sendai, Japan. ynak@mail.cc.tohoku.ac.jp |
| |
Abstract: | The most fundamental parameters concerning an interaction between a ligand and a protein are equilibrium constants and the number of binding sites. The Scatchard plot has for a long time been widely used to obtain those parameters. However, controversy in 1982-1983 over the reliability of this plot (the graphical estimation of the number of identical independent sites from the x-intercept) indicated that some methodologies other than the Scatchard plot are expected. Over the past decade, we have developed a method for applying multivariate analysis to the problem of determining spectral features of a ligand associated with a protein molecule. In principle, this method is based mainly on the computer-assisted adjustment of dissociation constants to an assumed reaction model. We discovered in this process that an n-parameter, introduced into an equation for calculating the amount of dye ligand bound to a protein, coincided with the number of identical independent sites, under a certain condition in principal factor analysis calculation. In this study, we established a new methodology for determining the number of identical independent sites using synthesized spectral series, and we then applied this method to a simple reaction system composed of bovine serum albumin (BSA) and bromocresol purple (BCP) anions. BSA was found to have two identical independent sites for BCP anions at pH 8.8. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|