Manipulating Monomer-Dimer Equilibrium of Bovine β-Lactoglobulin by Amino Acid Substitution

Sakurai, Kazumasa; Goto, Yuji

Journal of Biological Chemistry, 2002, 277(28), 25735-25740

Number of Access:468（2025-08-30 01:41 Counts）

Identifier to cite or link to this item: https://hdl.handle.net/11094/71301

Link to primary information 

File Format Terms of use Size Views Date.Available Description information
JBC_25735-40 pdf None 538 KB 249 2019.02.26  

Item Information

Output File Export EndNote Basic Export Mendeley

Title
Manipulating Monomer-Dimer Equilibrium of Bovine β-Lactoglobulin by Amino Acid Substitution
Creator
NRID
1000010403015 1000010403015
CreatorName
Sakurai, Kazumasa
NRID
1000040153770 1000040153770
researchmap permalink
read0014440 read0014440
CreatorName
Goto, Yuji
Description
This research was originally published in the Journal of Biological Chemistry. Kazumasa Sakurai and Yuji Goto. Manipulating Monomer-Dimer Equilibrium of Bovine β-Lactoglobulin by Amino Acid Substitution. J. Biol. Chem. 2002; 277, 25735-25740. © the American Society for Biochemistry and Molecular Biology
Abstract
Bovine β-lactoglobulin, a major protein in cow's milk composed of nine β-strands (βA–βI) and one α-helix, exists as a dimer at neutral pH while it dissociates to a native monomer below pH 3.0. It is assumed that the intermolecular β-sheet formed between I-strands and salt bridges at AB-loops play important roles in dimer formation. Several site-directed mutants in which intermolecular interactions stabilizing the dimer would be removed were expressed in the methylotrophic yeast Pichia pastoris, and their monomer-dimer equilibria were studied by analytical ultracentrifugation. Various I-strand mutants showed decreases in K a, suggesting that the intermolecular β-sheet is essential for dimer formation. By substituting either Asp33 or Arg40 on the AB-loop to oppositely charged residues (i.e. R40D, R40E, and D33R), a large decrease in K a was observed probably because of the charge repulsion, which is consistent with the role of electrostatic attraction between Arg40 on one monomer and Asp33 on the other monomer in the wild-type dimer. However, when two of these mutants, R40D and D33R, were mixed, a heterodimer was formed by the electrostatic attraction between Arg33 and Asp40 of different molecules. These results suggested that protein-protein interactions of bovine β-lactoglobulin can be manipulated by redesigning the residues on the interface without affecting global folding.
Publisher
American Society for Biochemistry and Molecular Biology
Source Title
Journal of Biological Chemistry
Volume (Issue)
277(28)
Page
25735-25740
Date of Issued
2002-07
Language
English
Handle URL
https://hdl.handle.net/11094/71301
eISSN
1083351X
NCID
AA1202470X
Relation.isIdenticalTo
DOI (Publisher Version)
https://doi.org/10.1074/jbc.M203659200
Access Rights
open access
oaire:version
Version of Record
Category
学術雑誌論文 Journal Article