J. Biochem, 1974, Vol. 76, No. 6 1165-1173
© 1974 Japanese Biochemical Society
research-article |
Transport of Sugars and Amino Acids in Bacteria
XII. Substrate Specificities of the Branched Chain Amino Acid-binding Proteins of Escherichia coli*
Faculty of Pharmaceutical Sciences, University of Tokyo Hongo, Bunkyo-ku, Tokyo 113
A simple procedure was developed for preparing two species of branched chain amino acid-binding proteins of Escherichia coli. The procedure involved osmotic shock, fractionation with ammonium sulfate and chromatography on DEAE-Sephadex and DEAE-cellulose columns. The major binding protein binds leucine, isoleucine, and valine and is referred to as LIV-BP, while the minor binding protein binds only leucine and is referred to as LS-BP.
Antibody against purified LIV-BP was prepared in rabbits. The antibody gave a single precipitin line with LIV-BP in an Ouchterlony double diffusion plate. The antibody also cross-reacted with LS-BP, but spur formation was observed, indicating a difference in the antigenicities of the two proteins.
A protein released by osmotic shock having binding activity for threonine was studied. The protein was co-purified with the LW-BP activity, and purified, homogeneous LIV-BP was competitively inhibited by threonine. Based on these findings we propose that LfV-BP should be referred to as LIVT-BP, which specifically binds leucine, isoleucine, valine, and threonine.
The structure-binding activity relationship of the two binding proteins was investigated using various compounds which are structurally related to branched chain amino acids.
*This work was supported in part by a grant from the Ministry of Education (C758034), Japan
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
A. L. Davidson, E. Dassa, C. Orelle, and J. Chen Structure, Function, and Evolution of Bacterial ATP-Binding Cassette Systems Microbiol. Mol. Biol. Rev., June 1, 2008; 72(2): 317 - 364. [Abstract] [Full Text] [PDF] |
||||
